occupational safety and health branch Ø Ç Ì Ú · 2019. 1. 7. · code of practice for safe use...

2

This Code of Practice is prepared by the Occupational Safety and Health Branch Labour Department January 2004 First Edition September 2017 Second Edition xxxx Third Edition This Code of Practice is issued free of charge and can be obtained from offices of the Occupational Safety and Health Branch or downloaded from website of the Labour Department at http://www.labour.gov.hk/eng/public/content2_8.htm. Addresses and telephone numbers of the offices can be found by telephone 25592297. This Code of Practice may be freely reproduced except for advertising, endorsement or commercial purpose. Please acknowledge the source as “Code of Practice for Safe Use of Mobile Cranes”, published by the Labour Department.

4

CCONTENTS

Foreword ........................................................................... 1

1. Scope............................................................................. 2

2. Definitions ..................................................................... 3

3. Management of the Lifting Operation......................... 5

3.1 Safe system of work ................................................................ 5

3.2 Control of the lifting operation.................................................. 6

4. Planning of the Lifting Operation................................ 7

5. Responsibilities/Requirements of Personnel ............ 9

5.1 Owner’s responsibilities ........................................................... 9

5.2 Mobile crane operator .............................................................. 9

5.3 Slinger ................................................................................... 10

5.4 Signaller ................................................................................. 11

6. Selection of Mobile Cranes........................................ 12

6.1 General .................................................................................. 12

6.2 Types of mounting and jib configuration ................................ 13

7. Markings and Documentation ................................... 17

7.1 Identification .......................................................................... 17

7.2 Safe working load charts ....................................................... 17

7.3 Instruction manuals and log book .......................................... 17

8. Operational Features of Mobile Cranes.................... 19

5. Responsibilities5. Responsibilitie

5.15 Owner’s resp resp

5.25 Mobile crane crane

5.35 Slingerger ...........

5 45 4 Si ll

sibilitiessibilities............

peratorator...........

......................... ..

........................................ ...

......................................

.............................................

............................

nelel ...........

.......................

.......................

.......................

99

.. 99

.. 99

1010

11

....

.....

.....

... 1

1

5

8.1 Automatic safe load indicator ................................................ 19

8.2 Brakes.................................................................................... 19

8.3 Cabins for operators .............................................................. 19

8.4 Operating controls ................................................................. 20

8.5 Guards and protective structures .......................................... 20

8.6 Outriggers .............................................................................. 21

8.7 Drum assemblies ................................................................... 21

8.8 Sheaves ................................................................................. 21

8.9 Safety features ...................................................................... 22

9. Siting of Mobile Cranes.............................................. 24

9.1 General .................................................................................. 24

9.2 Crane standing or supporting conditions ............................... 24

9.3 Proximity hazards .................................................................. 27

10. Erection, Dismantling and Transportation ............. 31

10.1 General precautions for erection and dismantling ................. 31

10.2 Folding or hinging jibs ........................................................... 32

10.3 Jib assembly .......................................................................... 33

10.4 Jib suspension ....................................................................... 34

10.5 Load hoist rope ...................................................................... 34

10.6 Safety devices ....................................................................... 36

10.7 Crane stability, erection and dismantling procedures ........... 36

10.8 Tyres ...................................................................................... 37

10.9 Travelling and transportation ................................................. 37

11. Procedures and Precautions ................................... 39

gg

9.19 Generaleral .............

9.29 Crane standin andin

9.39 Proximity hazy haz

10. Erection, Dism0. Erection, Dis

or supporting or supporting

ds .......................

ntling and ing

conditions onditions............

.................................

TransportatioTransporta

d di l d di

........................ 22

.......................

.......................

.......................

on .................

2424

2424

2727

3131

31

... 2

... 22

... 2

.. 3

6

11.1 Suspension of load ................................................................ 39

11.2 Leaving the crane unattended for a short period ................... 39

11.3 Leaving the crane unattended for a long period of time ........ 39

11.4 Routine Checks ..................................................................... 40

11.5 Permit to work for maintenance ............................................. 43

11.6 Safe means of access ........................................................... 44

12. Safe Working Loads and Operating Conditions.... 45

12.1 Mode of operation and control ............................................... 45

12.2 Safe working loads ................................................................ 46

12.3 Near maximum working loads ............................................... 51

12.4 Travelling with suspended loads ........................................... 51

12.5 Carrying of persons by crane ................................................ 53

12.6 Communication system ......................................................... 54

12.7 Weather conditions ................................................................ 55

12.8 Mobile cranes for other duties ............................................... 56

13. Maintenance.............................................................. 60

13.1 Statutory requirements .......................................................... 60

13.2 Planned maintenance ............................................................ 60

13.3 Competence of maintenance personnel ................................ 60

14. Inspection, Examination and Testing ..................... 61

15. Securing of Loads before Lifting ............................ 63

15.1 Loads to be safely secured .................................................... 63

15.2 Precautions to be taken before the lifting operation .............. 63

12.12.33 Near maximuNear

12.41 Travelling witelling w

12.51 Carrying of pe of pe

12.61 Communicatinicati

12.71 Weather condher co

12 812 8 Mobile crane Mobil

sons by craneons by crane

system ystem ........

onss...................

or othe or other dutier d

.........................................

.............................. ...

.............................................

.........................................

................................. 55

.......................

.......................

.......................

.......................

5151

5353

5454

5555

... 5656

... 5

... 55

... 5

... 5

5

7

15.3 Methods of slinging, their application and limitations ............ 66

15.4 Precautions to be taken in fitting the slings ........................... 72

Table 1 - Recommended hand signals ......................... 73

Table 2 - Frequency of test, thorough examination and inspection of mobile cranes under the LALGR ........... 74

References ...................................................................... 75

8

LList of Figure Fig. 1 Types of mounting for mobile cranes…………………………………….…………………………. 15 Fig. 2 Types of jib and fly-jib on mobile cranes…………………………………………………………… 16 Fig. 3 Typical mobile crane shown with outriggers set……….…………………………………… 25 Fig. 4 Position of mobile crane……………………………………………………….……….……………….…..…… 27 Fig. 5 Travelling under overhead electric lines and cables………………………………..… 29 Fig. 6 Typical rope and suspension systems on mobile cranes…………………….….. 35 Fig. 7 Influence of rope stretch on board operation……………………………………….……….. 50 Fig. 8 Vertical or straight lift………………………………………………………………………….…………….……… 68 Fig. 9 Basket hitch…………………………………………………………………………………………..…………………….. 68 Fig. 10 Simple choker hitch……………………………………………………………………………….…….……………. 68 Fig. 11 Double and choked………………………………………………………………………….……..………..….... 68 Fig. 12 Choker hitch double wrapped…………………………………………………………….…………..…... 69 Fig. 13 Two single-leg slings used with direct attachment………………………………..……. 69 Fig. 14 Two single-leg slings used in choker hitch……………………………………………………. 70 Fig. 15 Two single-leg slings used in basket hitch� ………………………………..…………….... 70 Fig. 16 Two single-leg slings in double wrap choker hitch….………………………….……… 71 Fig. 17 Two single-leg slings in double wrap basket hitch…………………….…….………….. 71 Fig. 18 Three-leg sling………………………………………………………………………………………….…...……………. 71 Fig. 19 Four-leg sling…………………………………………………………………………..……………….………………….. 71

Fig. 8Fig. 8 Vertical or straiVertical or st gh

Fig. 9ig. 9 Basket hitch…………h…………

Fig. 10ig. 1 Simple choker hiter hit

Fig. 11ig. 1 Double and choke nd cho

Fi 12Fi 12 Ch k hit h dCh k d d

……………………………………………………

………………………………………… …

………………………………………

………………………………………………

……………………………………………

………………………………………………………………

……….…………………….………

……..…..……………………………………

……………..………….………

…….……..………..………..…

6868

. 68

686

6969

……..…..

…….

…....

Code of Practice for Safe Use of Mobile Cranes

1

FForeword Mobile cranes are widely used for lifting operations in industrial undertakings in Hong Kong especially in the construction industry. Every year, there are quite a number of accidents involving mobile cranes, such as overturning of cranes and displacement of loads being lifted. Property damage and bodily injuries can be avoided if they are properly used. This Code of Practice (hereafter referred to as this Code) is issued by the Commissioner for Labour under Section 7A of the Factories and Industrial Undertakings Ordinance (Cap. 59). It provides practical guidance to the industry as to how to use mobile cranes safely and properly with a view to assisting the duty holders in preventing accidents. The provisions in this Code should not be regarded as exhausting those matters which need to be covered by the relevant safety legislation, nor is it intended to relieve persons undertaking the work of their statutory responsibilities. It is important to note that compliance with this Code does not of itself confer immunity from legal obligations. This Code has a special legal status. A failure to observe a provision of this Code is not in itself an offence. However, that failure may in criminal proceedings be relied on by any party to the proceedings as tending to establish or to negative any liability which is in question in the proceedings, if the said provision is found by the court to be a matter to which a contravention or failure alleged in the proceedings relates (see section 7A(5) of the Factories and Industrial Undertakings Ordinance (Cap. 59)). Throughout this Code, we have quoted the relevant safety standards of the British Standards Institution. However, if there are some other national, international standards or provisions which are equivalent, they would be acceptable as alternatives. In addition, statutory provisions referred to or cited in this Code are those in force as at XX XXXXX 201x.

The provisions in this CoThe provisions in this which need to be covere which need to be covererelieve persons undertakelieve persons undertakimportant to note that commportant to note that comfrom legal obligations. om legal obligations.

This Code has a special This Code has a spC d i t i it lf ffC d i t i

g the work of g the work of ance with this ce with this

gal status. A al sta H H

their statutory r heir statuto Code does not of Code does not

failure failure to observ to observ hat failure may in t failure may

usting those mang t nor is it inter is

sponsibilities sponsibilitie tself confer imf co

e a provision a prov i i l i i l

atters tered to ed t

It is It is munity muni

of this of this ceedings ings

maends. s.

mm

n o

2

11.. Scope

11. Scope 1.1 This Code provides guidance on the safe use and operation of mobile

cranes to ensure the safety of personnel working at or nearby those cranes.

1.2 It covers management and planning of the lifting operation of mobile

cranes, requirements for operators, slingers and signallers, siting, erection, dismantling, maintenance and testing of mobile cranes. It also contains guidance pertaining to the selection, safe use and specific precautions when mobile cranes are operating within a workplace.

1.3 Reference is also made to relevant Hong Kong legislation in particular

Sections 6A & 6B of the Factories and Industrial Undertakings Ordinance (Cap. 59) (hereafter referred to as the FIUO), the provisions in the Factories and Industrial Undertakings Regulations (hereafter referred to as the FIUR), the Factories and Industrial Undertakings (Lifting Appliances and Lifting Gear) Regulations (hereafter referred to as the LALGR), the Factories and Industrial Undertakings (Guarding and Operation of Machinery) Regulations (hereafter referred to as the GOMR) and the Construction Sites (Safety) Regulations (hereafter referred to as the CSSR). Attention is drawn to the requirements and procedures for testing and examination of cranes under the LALGR and the British Standard BS 7121.

SectionsSect 6A & Ordinancedinance (Cap (Cin the Factorie Factorireferred to as o as (Lifting Appliancpliancas the LALGR) ALGRand Operation eration GOMR) and thGOMR) an

f d t tf

e FIUR), the e FIUR), the s and Lifting G nd Lifting

he Factories Fac Machinery) Reachin Construction onstr CSSR) Att CSSR)

actories and Indctories and ear) Regulations ar) Regulatio

nd Industrial Un Industrial gulations (hereaftgulations (her

Sites (Safety) R Sites (Safety) Rtion is drawn to tn is drawn t

ustrial Underta Underta IUO), the proviO), tegulations (hatioustrial Undeustrial Unde

hereafter refeaftertakings (Gakin

er referred to efergulations (hlation

h i h i

sions oneafter eaftekings kings

red to ed tarding ardin

as the s theafter eafter

ents and and

rovi here

ertaertaferr

Gua o a

heret


3

22. D

efin

ition

s

22. Definitions Automatic safe load indicator

It means a device intended to be fitted to a crane that automatically gives an audible and visible warning to the operator thereof that the crane is approaching its safe working load, and that automatically gives a further audible and visible warning when the crane has exceeded its safe working load (Regulation 3(1) of the LALGR). Competent examiner

A competent examiner, in relation to the carrying out of any test and examination required by the LALGR, means a person who is -

(a) appointed by the owner required by those regulations to ensure that the test and examination is carried out;

(b) a registered professional engineer registered under the Engineers Registration Ordinance (Cap. 409) within a relevant discipline specified by the Commissioner for Labour; and

(c) by reason of his qualifications, training and experience, competent to carry out the test and examination.

(Regulation 3(1) of the LALGR) As at the date of this Code, Mechanical Engineering and Marine & Naval Architecture are the disciplines specified by the Commissioner for Labour. Competent person

A competent person, in relation to any duty required to be performed by him under the LALGR, means a person who is -

(a) appointed by the owner required by those regulations to ensure that the duty is carried out by a competent person; and

(b) by reason of training and practical experience, competent to perform the duty.

(Regulation 3(1) of the LALGR)

(a) appointed by the owna) appointed by the oand examination is caand examination is c

(b) a registered profeb) a registered profeRegistration OrdinancRegistration OrdinancCommissioner for LaCommissioner for La

(c) by reason of his quac) by reason of his out the test and examout the test a

onal engineeonal enginee (Capap. 409) wit. 4ur; and and

cations, traininions atiation.on.

registered un registered n a relevant discn a relevant d

g and experience g and experien

ensure that the sure

der the Ender the Epline specifiee sp

competent ompe

e test te

neers neers by the by th

carry carry

the

nginied b

to

4

22. Definitions

CCondition of tipping

A condition when a crane is subjected to an overturning moment which cannot be increased by even a small amount without causing the crane to fall over. Owner

Owner, in relation to any crane or lifting gear, includes the lessee or hirer thereof, and any overseer, foreman, agent or person in charge or having the control or management of a crane or lifting gear, and the contractor who has control over the way any construction work which involves the use of the crane or lifting gear is carried out and, in the case of a crane or lifting gear situated on or used in connection with work on a construction site, also includes the contractor responsible for the construction site (Regulation 3(1) of the LALGR).

A contractor is responsible for a construction site if he is undertaking construction work there or, where there is more than one contractor undertaking construction work at the site, if he is the principal contractor undertaking construction work there (Regulation 3(2) of the LALGR). Specified body

It means-

(a) the body known as the Construction Industry Training Authority before the commencement of section 71 of the Construction Industry Council Ordinance (Cap 587); or

(b) the Construction Industry Council established by section 4 of the Construction Industry Council Ordinance (Cap 587).

A contractor is responsiblA contractor is respowork there or, where therwork there or, where thwork at the site, if he is work at the site, if he is there (Regulation 3(2) of there (Regulation 3(2) of t

Spec yyy

It means-

e principal co rincipal co LALGR). LALGR).

tractor undertakior und

)

ertaking construing construertaking consking g constructiog construct

uction uctio work work

struon


5

33. M

anag

emen

t of t

he

LLifti

ng O

pera

tion

3. Management of the Lifting Operation 3.1 Safe system of work 3.1.1 A safe system of work should be established and documented. This

should be followed for every lifting operation whether it is an individual lift or a group of repetitive operations. This safe system of work should be prepared and endorsed by the owner/contractor of mobile crane, with the advice of the competent person, safety officer and other relevant personnel. The same principle should be applied whether the lifting operations are carried out at a site, in a factory or at a dock. The safe system of work should be effectively communicated to all parties concerned.

3.1.2 The safe system of work should include the following:

(a) risk assessment;

(b) planning of the operation;

(c) taking care of the safety of all workers involved and other persons who may be affected by the lifting operation, including fencing off all lifting zones as far as reasonably practicable;

(d) selection, provision and use of a suitable mobile crane and equipment;

(e) maintenance, examination and testing of the mobile crane and equipment;

(f) the provision of a log-book for the competent examiner/competent person/mechanic to enter the details of testing, examination, inspection, maintenance/repair works which have been carried out for the mobile crane;

(g) the provision of properly trained and competent personnel who have been made aware of their relevant responsibilities under the Sections 6A & 6B of the FIUO;

(h) adequate supervision by properly trained and competent personnel;

(i) observing for any unsafe conditions such as adverse weather conditions that may arise during operation;

3.1.2 The safe system 3.1.2 The safe sys

(a) risk assess assess

(b) planning of ng of

(c) taking care g care who may bo may lifting zonelifting z

ent;

e operation; operation;

f the safety of e sa ffected by the cted s far as reason far as

ll workers involve orkers inv fting operation, in fting operationably practicable; ably practicable;

g:

d and other nd o cluding fencding in

rsons rson off all off a

peng

6

33. Managem

ent of the LLifting O

peration

(j) ensuring that all necessary test and examination certificates and other documents are available;

(k) preventing unauthorized movement or use of a mobile crane at all times; and

(l) the contingency plan providing procedures to be followed in case of emergency situation.

3.1.3 The lifting operation should be taken to include any necessary

preparation of a site, and the siting, erection, alteration and dismantling of the crane.

3.2 Control of the lifting operation 3.2.1 To ensure the implementation of the safe system of work, a responsible

person should be appointed by the owner to have overall control of the lifting operation. This appointed person should:

(a) be fully conversant with crane operation and crane maintenance;

(b) have adequate practical experience in mechanical engineering;

(c) be familiar with hazards, limitations and precautions associated with crane operation;

(d) have properly trained in the safe use of mobile cranes including the theory of crane operation;

(e) be familiar with the provisions of the LALGR and the contents in this Code;

(f) ensure the safe system of work is fully understood by the personnel associated with the lifting operation; and

(g) be capable of performing inspections on mobile cranes and tests in accordance with the manufacturer’s instructions.

3.2.1 To ensure the i3.2.1 To ensuperson should bon shoulifting operation eration

(a) be fully cony con

(b) have adequ adeq

(c) be familiar familiacrane opercrane

rsant with cranrsant with cran

e practical exp ract

h hazards, lim azaon;;

e operation and cr operation an

rience in mechane in mec

ations and precauations and pre

f work, a responk, a respon overall control orall

ane maintena ane mainten

cal engineer eng

tions associas as

of the f th

ce; ce;

;;

d with d wit

ol o

anc

ring

ated


7

44. P

lann

ing

of th

e LLi

fting

Ope

ratio

n 3. M

anagement of the

Lifting Operation

4. Planning of the Lifting Operation 4.1 All lifting operations should be planned to ensure that they are carried

out safely and that all foreseeable risks have been taken into account. Planning should be carried out by personnel who have the appropriate expertise and have been appointed for this purpose. In case of repetitive or routine operations, this planning may only be necessary in the first instance, with periodic reviews to ensure that no factors have changed.

4.2 Planning should include the consideration of:

(a) the load such as its characteristics and the method of lifting;

(b) the selection of a suitable mobile crane appropriate to the operation ensuring that adequate clearances are maintained between the load and the crane structure;

(c) the selection of suitable lifting gear, the weight of which should be taken into account when assessing the load on the mobile crane;

(d) the selection of suitable personnel for the operation;

(e) the proper position of the mobile crane and the load before, during and after the operation;

(f) the proper fencing off of all lifting zones (e.g. providing fencing or barricade) with suitable warning notices displayed; or where it is not reasonably practicable to fence off the lifting zones due to space constraint, etc., the taking of effective measures, such as appointment of sufficient watch-out personnel, to ensure no unauthorized entry into the zones;

(g) the site of the operation, taking into account proximity hazards, space availability and suitability of the ground such as the allowable bearing capacity of the ground;

(h) any necessary erection, alteration and dismantling of the mobile crane;

(i) the environmental conditions that exist or may occur at the site of the operation, which may necessitate stopping the operation when conditions are unsuitable; and

load and thload a

(c) the selectio selecttaken into a into a

(d) the selectio lectio

(e) the proper prope and after thand afte

(f)(f) th

ount when assount when ass

of suitable pers suitab

sition of the mon o operation; eratio

i ff i ff f ll f

essing the load on sing the loa

onnel for the opernnel for the o

bile crane and thbile crane and

ifting zones (e g ng zones (e

tained between between

t of which sh wh the mobile c the mobile c

ation; n;

e load before ad b

idi f idi

uld be uld bne; ne;

during durin

ncing or g or

hou cran cran

e, d

i

8

44. Planning of the

LLifting Operation

(j) the effectiveness of communication among relevant parties, such as that between the operator and the signaller(s).


9

55. R

espo

nsib

ilitie

s/

RReq

uire

men

ts o

f PP

erso

nnel

5. Responsibilities/Requirements of Personnel 5.1 Owner’s responsibilities 5.1.1 The owner is responsible for putting together the safe system of work,

educating all related personnel in safe practices and the assignment of definite, individual safety responsibilities. The owner must plan all phases of the operation involving the mobile crane.

5.1.2 It is the responsibility of owner to ensure that the persons who prepare

the mobile crane, erect it, operate it, and work with it are well trained in both safety and operating procedures.

5.1.3 The owner must ensure that all mobile cranes are operated by trained,

experienced, competent and qualified crane operator. 5.1.4 The owner must also ensure that the persons who direct, rig and handle

the loads have received proper training in the principles of the operation, are able to establish weights and judge distances, heights and clearances, are capable of selecting tackle and lifting gear as well as rigging method suitable for the loads to be lifted, and are capable of directing the movement of the crane and load to ensure the safety of all personnel.

5.2 Mobile crane operator

5.2.1 The mobile crane operator should ensure at all times the safe operation of the crane under his control. He should follow the correct operation of the crane in accordance with the manufacturer’s instructions and within the safe system of work. He should at any one time only respond to the signals from one slinger/signaller who should be clearly identified. In particular, the mobile crane operator should:

(a) have attained the age of 18 years and hold a valid certificate issued by the specified body or by any other person specified by the

5.1.3 The owner mus .1.3 The owner muexperienced, coced, co

5.1.4 The owner mus .1.4 The owner mus the loads have have are able to e ble to clearances, are clearanc

petent and quatent and qua

lso ensure tha enseived proper ted p

ablish weights sh apable of sele apable of

fied crane operat crane o

the persons who he persons w ining in the princning in the pr

and judge dist and judge ting tackle and ling tackle and li

operated by erateor. r.

direct, rig and ct, rples of the ops of tances, heighes,

ting gear as ting gear a

ained, ained

andle andation, atio and an

s well as ell as

tra

d ha pera

hts s we

10

55. Responsibilities/

RRequirem

ents of PP

ersonnel

Commissioner for Labour (Regulation 15A(1) of LALGR);

(b) be fit, with particular regard to eyesight, hearing and reflexes;

(c) have been trained in the general principles of slinging and be able to establish weights and judge distances, heights and clearances;

(d) have been adequately trained in the operation of the type of crane he is operating and have sufficient knowledge of the crane and its safety devices;

(e) understand fully the duties of the slinger and be familiar with the signal code shown in Table 1 in order to implement safely the instructions of the slinger or signaller; and

(f) understand fully the radio/tele-communication signals between the parties concerned.

5.3 Slinger 5.3.1 The slinger should be responsible for attaching and detaching the load

to and from the crane, and for the use of correct lifting gear in accordance with the planning of the operation. In particular, the slinger should:

(a) have attained the age 18 years;

(b) be fit, with particular regard to eyesight, hearing and reflexes;

(c) have been trained in the general principles of slinging and be able to establish weights and judge distances, heights and clearances;

(d) be capable of selecting tackle and lifting gear as well as rigging method suitable for the loads to be lifted;

(e) understand fully the signal code shown in Table 1 and be able to give clear and precise signals;

(f) be capable of directing the movement of the crane and load in such a manner as to ensure the safety of personnel and plant; and

(g) understand fully the radio/tele-communication signals between the parties concerned.

55..33 Slinggeerr

5.3.1 The slinger sho.3.1 The slinger shoto and from tom taccordance with ce witshould:

(a) have attain(a) have

d be responsib be responsib crane, and fane,

he planning of plan

the age 18 ye the age 18

e for attaching an for attaching r the use of cor the use of

he operation. In operation.

rs; s;

d detaching d detaching rrect lifting ct li

particular, the ticul

e load e load ear in ar

linger linge

the the ge

e s


11

55. R

espo

nsib

ilitie

s/

RReq

uire

men

ts o

f PP

erso

nnel

5.4 Signaller 5.4.1 Where the crane operator of the mobile crane does not have a clear and

unrestricted view of the load carried by the crane, its vicinity or the point of attachment for a load where no load is being carried and such view is necessary for the safe working of the crane, a signaller shall be employed to relay the slinger’s instructions to the crane operator (Regulation 15B(1) of LALGR).

5.4.2 The signaller should be responsible for relaying the signal from the

slinger to the crane operator. He is also responsible for directing the safe movement of the crane. He should not be engaged in other activities while giving signal to the crane operator. In particular, he should:

(a) have attained the age 18 years (Regulation 15B(2) of LALGR);

(b) be fit with particular regard to eyesight, hearing and reflexes;

(c) understand fully the signal code shown in Table 1 and be able to transmit the instructions of the slinger in a clear and precise manner;

(d) be easily identifiable to the crane operator (e.g. by wearing `high-visibility’ clothing, or other means); and

(e) understand fully the radio/tele-communication signals between the parties concerned.

(b) be fit with p be fit wit

(c) understand rstand transmit the mit the

(d) be easily id sily ivisibility’ clobility’ c

(e) understand (e) underi

ully the sig the signal na nstructions of th structions of th

ntifiable to the able ing, or other m, or

lly the radio/tey the rdd

ode shown in Ta hown e slinger in a clea e slinger in a c

crane operator (e operato ans); andans); a

ee-communication -communication

B(2) of LALGR); LALGR);

and reflexes; d ref

ble 1 and be 1 a and precise and precise

g. by wearin by w

signals betw gnals b

ble to ble t anner; anner;

`high- `high

en the n the

s;

e ab ma

ng `

wee

12

66. Selection of

MMobile C

rane

6. Selection of Mobile Cranes 6.1 General 6.1.1 Each class of cranes possesses certain basic characteristics which will

usually dictate the one most suited to a particular application. Mobile cranes must be properly selected to suit the job. If the crane’s basic characteristics do not match the job’s requirements, unsafe conditions will be created and accidents are prone to happen.

6.1.2 Reference should therefore be made to the following sub-section 6.2 for

details of different crane types and their operational characteristics. 6.1.3 The type of mobile cranes to be used should be considered against the

job requirements for a particular application. Points to be considered in making the selection include:

(a) weights and dimensions of loads;

(b) heights of lift and distances/areas of movement of loads;

(c) number and frequency of lifts;

(d) length of time for which the crane will be required;

(e) site conditions, including ground conditions for crane standing, and space available for crane access, erection, operation and dismantling;

(f) any special operational requirements or limitations imposed including the existence of other cranes in close proximity; and

(g) any dynamic loads involved. 6.1.4 In general, all the points in sub-section 6.1.3 can influence the choice of

the crane. With the consideration of the above points, the crane to be selected should be:

(a) capable of making all its lifts in its standard configuration;

(b) having at least a 5% working/safety margin with respect to the load capacity on every lift;

6.1.3 The type of mo6.1.3 The tyjob requirement requiremmaking the he sele sel

(a) weights an ts an

(b) heights of lts of l

(c) number an mber a

(d) length of tim(d) lengt

imensions of lo imensions of lo

and distances/d dis

requency of liftuen

for which the c for which

ads; ads;

reas of movemen movem

ane will be requir ane will be requir

nsidered againsred againss to be consider be

of loads; load

ed; ed;

red in d der


13

66. S

elec

tion

of

MMob

ile C

rane

(c) having sufficient clearance for the boom; and

(d) having adequate headroom between the load and rigging required to make the lift.

6.2 Types of mounting and jib configuration 6.2.1 The operating characteristics of a mobile crane are largely determined

by its type of mounting and type of jib (see Fig. 1 & 2). 6.2.2 Crawler-mounted crane (Fig. 1a) - a crane which is mounted on crawler-

tracked chassis. The crane can travel under its own power. A crane cabin is usually provided for the crane driving and operation purposes. A single power unit is provided for both the crane driving and operation modes.

This type of crane should be considered under the following conditions:

(a) the ground is poor to travel over or sloped;

(b) operation in areas of limited access; or

(c) handling of dynamic loads such as vibrators. The tracks of the crane which provide large ground-bearing area have

prevented the sinkage of it on soft or unpaved ground to enhance its operational stability. Crawler-mounted crane is highly manoeuverable and can be turned virtually about its own centre.

6.2.3 Truck-mounted crane (Fig. 1b) - a crane which is mounted on a truck

chassis with or without a spring suspension. Apart from the driving cabin, a crane with higher lifting capacity is usually provided with a separate control cabin. As far as the power to drive the crane is concerned, the crane and the truck can be driven by either a single power unit or by separate power units.

6.2.4 Lorry-mounted crane (Fig. 1c) – a crane which is mounted on a lorry

usually power-driven and with a load carrying capability. The crane mainly consists of a column that slews about a base and a boom system that is fixed on top of the column.

modes. modes.

This type of cra This type of cra

(a) the ground ound

(b) operation in ation i

(c) handling of ndling

should be conld be co

poor to travel o oor to travel o

reas of limited as of

ynamic loads smic

ver or sloped; er or sloped;

ccess; or ss; or

ch as vibrators. ch as vibrators

driving and oper nd ope

ollowing condwing ons:ons:ditio

14

66. Selection of

MMobile C

rane

6.2.5 Wheel-mounted crane (Fig. 1d) - a crane which is mounted on wheeled chassis. The crane can travel under its own power. A crane cabin is usually provided for the crane driving and operation purposes. A single power unit is provided for both the crane driving and operation modes.

The following conditions are required for these types of crane:

(a) operation on hard or compacted ground; and

(b) good access to the operating area is provided. In this respect, load bearing capacity of access routes should be properly assessed.

6.2.6 In general, local lifting operations would use wheel-mounted or crawler-

mounted crane. While those involving considerable travelling between sites during lifting operations would use truck-mounted crane.

6.2.7 Telescoping jib Its operationally-variable jib length can greatly facilitate manoeuvring

and placing the load in confined areas. The operational set-up and strip down times of this kind of jibs are shorter than other type. However, working loads at longer radii are less than those at comparable radii of a lattice-construction strut jib and the maximum length of the jib is restricted due to the jib's relative heavier weight (see Fig. 2a).

6.2.8 Strut-type jib It would provide greater heights of lift and maximum operating radii, and

hence suitable for long range work or high lifts (see Fig. 2b). 6.2.9 Fly-jib It would be suitable for operations involving the handling of relatively

light loads to extremes of height (see Fig. 2b).

6.2.6.2.7 Telescoping jibTelesco Its operationally Its operation

and placing the cing thstrip down timn timHowever, work workcomparable radle ralength of the jib of the jFig. Fig. 2a). 2a).

of this kind of this kind g loads at l loads

of a lattice-co a la restricted due stric

of jibs are shorf jibs are snger radii are nger radii anstruction strut jiruction stru o the jib's relative o the jib's rela

cilitate manoeuate erational settionaer than otheer than oth

ess than ths thb and the m nd t heavier wei avie

uvring vrinp and p an type. type. se at se aimum imut (see t (se

oeut-up er er

hos maxi

ght


15

66. S

elec

tion

of

MMob

ile C

rane

Fig. 1 Types of mounting for mobile cranes (not relatively scaled)

Fig. 1b - Truck-mounted crane

Fig. 1a - Crawler-mounted crane

Fig. 1c - Lorry-mounted crane

Fig. 1d - Wheel-mounted crane

Wheels usually stay on the ground

Fig. 1a Fig. 1a -- CrawlerCrawler-mounte -mounted cranented crane

16

66. Selection of

MMobile C

rane

Fig. 2a – Telescoping jib (hydraulic)

Telescoping

Fig. 2 Types of jib and fly-jib on mobile cranes (not relatively scaled)

Fig. 2b – Strut-type jib and fly jib (lattice)

Intermediate sections

Offset angle

Pivot

Derricking rope

Jib derricking rope

Fly-jib offset

Fly-jib fixed guy ropes

Extended jib

Fly-jib

Basic jib

Headsection

Frontsection

Headsection

Jib derriccking ropeking rop

FlyFly--jib fixed guy rjib fixed guy --

Fly-

pespes

ly jibb

b offsetfset


17

77. M

arki

ngs

and

DDoc

umen

tatio

n

7. Markings and Documentation 7.1 Identification 7.1.1 The crane should have a permanent durable plate bearing the

manufacturer's name, machine model, serial number, year of manufacture and weight of the unit for identification purpose.

7.1.2 Every major structural, electrical and mechanical component of the

machine should have a permanent durable plate bearing the manufacturers' name, machine model number, serial number, year of original sale by the manufacturer and weight of the unit. Besides, identification numbers should be clearly marked on all basic removable components and attachments of the machine (such as counterweights etc.) to show that they belong to that machine. It is important that these components should be used only on that machine or identical models or an equipment for which they were specifically intended by the manufacturer.

7.2 Safe working lload charts 7.2.1 The crane shall have a substantial/durable safe working load chart

which:

(a) has clearly legible characters in English and Chinese and figures displayed inside the crane (Regulation 11(1) of the LALGR); and

(b) is easily visible to the crane operator. 7.3 Instruction manuals and log book 7.3.1 Manufacturer’s manuals containing all pertinent data relating to

operation and maintenance for the specific model of crane in use must be provided with each machine.

components ancompoetc.) to show t) to showthese compone omponmodels or an eq an eqmanufacturer. rer.

77..22 Saffee wwoorrkking

pment for whicpment for whic

ad cchhaarts

they were specif hey were sp

h as counterwe counterwe It is important is im machine or chin

cally intendecally intende

t that thaentical ntic by the by the

tant ideed bed b

18

77. Markings and

DDocum

entation

7.3.2 The language used in the majority of the workforce in Hong Kong, especially among the shop-floor operations and the middle supervisory staff, is Chinese. It is essential that all the written instructions, the documents and literatures given by the crane manufacturers in relation to the safe use and maintenance of the cranes (such as the load charts), if not in Chinese, be translated into Chinese so that the operatives have no difficulty in understanding them. Suitable arrangement should also be made to enhance communication in workplace where people would use languages other than Chinese or English.

7.3.3 If the equipment is not supplied with a log book then one should be

started, maintained and kept on the work site for the regular, periodic recording of all inspections, tests, repairs, maintenance, and hours of service related to the machine. All entries should be dated and signed by the operator, repairer or supervisor. The crane owner should ensure that the log book remains with the crane and is kept up-to-date throughout its working life in Hong Kong (see section 14 of this Code).

ensure that the ensure thathroughout its whout its

crane owner s wner s nd is kept up- kept up-toto

n 14 of this C 4 of de). e). Cod


19

88. O

pera

tiona

l FF

eatu

res

of

Mob

ile C

rane

8. Operational Features of Mobile Cranes 8.1 Automatic safe load indicator 8.1.1 All types of crane, except those with a maximum safe working load of 1

tonne or less or those operate with a grab or by electromagnetic means, shall be fitted with an automatic safe load indicator (Regulation 7B of the LALGR). The automatic safe load indicator is usually used in association with overloading cut-out. The specification of automatic safe load indicator should conform to British Standard BS 7262 or equivalent standards.

8.2 Brakes 8.2.1 Fail-safe brakes should be provided so that they will be applied

automatically to prevent any “free fall” of the hook or load whenever the hook or load is not in a power raising or power lowering condition. The brakes should be automatically applied if there is a loss of power or pressure. They cannot be released until the restoration of power and only when deliberately released.

8.2.2 Effective swing brake capable of stopping the swing with full load should

be provided. Besides, a positive swing lock or house lock designed to prevent accidental engagement or disengagement should be provided.

8.2.3 Fail-safe vehicle brakes should be provided to hold the crane stationary

under normal working condition or on the maximum grade for travel recommended by the manufacturer.

8.3 Cabins for operators 8.3.1 The operating cabin attached to the structure of the mobile crane should

meet the following requirements:

8..22 Brakess

8.2.1 Fail-safe brake.2.1 Fail-safe brakeautomatically to ally to hook or load is oad is brakes should s shoupressure. Thepressur

should be pr hould be p revent any ent a “fre

t in a power ra a p automatically utom

cannot be rele cannot be

vided so that tvided so tha fall ll” of the hook he hoing or power lowng or power

applied if there is applied if thersed until the rested until the rest

hey will be wi or load when oad ering conditiog co

a loss of p loss oration of pooration of p

pplied pplieer the er th The Thwer or wer o

wer and r and

apeve

on. pow

we

20

88. Operational

FFeatures of

Mobile C

rane

(a) be designed and constructed to protect the operator and the controls from the weather (Regulation 10(1) of LALGR);

(b) be provided with a roof of adequate strength to protect the operator from falling objects;

(c) be properly ventilated by artificial means where necessary;

(d) be fitted with a lock to prevent unauthorized entry when the unit is left unattended, unless the control unit can be separately locked;

(e) be constructed to give the operator a clear and unrestricted view that will enable him to use the crane safely (Regulation 10(1) of LALGR);

(f) have a safe access to and egress from the cabin.

(g) have guardrails provided on all outside and access platforms (see Regulation 38 B(1) of the CSSR, Regulation 24 of the FIUR);

(h) have hand holds and steps to facilitate entrance to and exit from the cabin; and

(i) all walking surfaces on the crane should be of anti-skid type. 8.4 Operating controls 8.4.1 All controls must be located within easy reach of the operator and allow

him ample room for operation. The controls should be of dead man switches in that they return to neutral automatically when released. The main power switch should be lockable and located within easy reach of the operator. Each control must be clearly labelled and marked to show the motion and the direction of movement that it controls. Where practicable, controls should be arranged so that accidental displacement is prevented and inadvertent pressure on them does not cause the crane to be set into motion.

8.5 Guards and protective structures 8.5.1 All exposed moving parts of a mobile crane such as gears, pulleys, belts,

chains, shafts, flywheels which might constitute a hazard under normal operating conditions shall be effectively guarded (see Regulation 5 of

(h) have hand (h) have hacabinbin; ; andand

(i) all walking lking

8..44 Operatiinngg cco

8 4 1 All l 8 4 1

rfaces on the cfaces on the c

olss

b l d i h b l d

ane should be of ne should be

n easy reach of th asy reach o

of the FIUR); IUR);

e to and exit from and exit fro

nti-skid type nti-skid type

nd allow low

.

d


21

88. O

pera

tiona

l FF

eatu

res

of

Mob

ile C

rane

the GOMR). 8.6 Outriggers 8.6.1 Outriggers should be securely held in the retracted position while

travelling. 8.6.2 They should also be securely held in the extended position when

blocked for hoisting. 8.6.3 If power actuated jacks are used, they should never lose pressure or

leak while under load. 8.6.4 The outrigger beams should be marked or painted in a manner to

indicate the fully extended position. 8.7 Drum assemblies 8.7.1 The drum assemblies should have adequate power. 8.7.2 The winding and unwinding directions of the drum should be clearly

marked in Chinese and English. 8.7.3 Rope should be correctly installed on drum. 8.8 Sheaves 8.8.1 Grooves should be smooth and slightly larger than the rope to prevent it

from being pinched or jammed in the groove. 8.8.2 Jib/boom hoisting sheaves should have pitch diameter of not less than

15 times the nominal diameter of the rope used. 8.8.3 Load hoisting sheaves should have pitch diameters not less than 18

times the nominal diameter of the rope used, and the load block

indicate the fully indicate the

8..77 Drum assseemmbb

8.7.1 The drum assem.7.1 The drum asse

8.7.2 The winding an8.7.2 The win

eess

lies should havs sho

unwinding dir unwinding

e adequate power adequate po

ctions of the dructions of the dru

ted in a mann a mann

m should be m should e clearly early e c

22

88. Operational

FFeatures of

Mobile C

rane

sheaves should also have pitch diameters not less than 16 times the nominal diameter of the rope used.

8.8.4 Depth of sheave grooves should be at least 1.5 times the rope diameter,

and the tapered side walls of the grooves should not make an angle of more than 18 degrees with respect to the centre line.

8.8.5 Bearings should be permanently lubricated or be equipped with means

for lubrication. 8.8.6 Sheave should be equipped with cablekeepers or close fitting guards to

prevent the rope from leaving the groove.

8.9 Safety features 8.9.1 The following should be provided to mobile cranes for the sake of safe

operation:

(a) jib/boom angle indicators should be installed for jib/boom which is capable of moving in the vertical plane. The indicator should be clearly visible and readable by the operator at his control station to the nearest degree;

(b) motion limit devices: These devices should be fitted to limit hoisting, derricking, travelling, slewing or any other crane motion. For example, automatic device should be installed to stop jib/boom drum motion when the maximum permissible jib/boom angle is reached;

(c) overload cut-out devices, if provided, should cut out crane motions when the crane is in an overload situation. This should not be achieved by stopping the prime mover. Only motions, that permit the crane to return to a safe condition, should remain operative. Besides, the overload cut-out device should be either of fail-safe design or protected from damage by excessive overloading;

(d) a spirit level for levelling the outriggers should be provided at the outrigger controls;

(e) a carpenter's level should be equipped at the machined surfaces on the revolving deck which are parallel to the jib/boom foot pins in the

8.9.1 The following s.9.1 The following operation::

(a) jib/boom aom acapable of ble of clearly visibrly visthe nearest the nea

(b) i li i

e indicators sh ndicators s oving in the vng i

and readable d re egree; ee;

i i Th Th

ould be installed ould be instalrtical plane. The plane.

y the operator at y the operato

evices should be ces should

for the sake the

or jib/boom w ib/b indicator sh dica

his control s con

i d li i i d li

f safe f saf

ich is ich ld be ld bion to ion t

hoisting ing

e of

wh hou stati

h i


23

88. O

pera

tiona

l FF

eatu

res

of

Mob

ile C

rane

horizontal plane for final precision levelling of the crane;

(f) rear view mirrors of each at least 625 cm2 in area should be equipped on both sides of crane;

(g) a suitable fire extinguisher should be installed and properly maintained;

(h) a suitable receptacle should be provided where storing tools and lubricating equipment on the crane is required;

(i) for wheel-mounted crane, wheel chocks should be provided to block movement on slopes when the crane is left unattended or undergoing repair/maintenance; and

(j) for night operation if required, adequate lighting and back-up lights should be provided.

24

99 Siting of

MMobile C

ranes

9. Siting of Mobile Cranes 9.1 General 9.1.1 In siting a mobile crane for operation, particular attention should be paid

to two factors: the crane standing or support conditions and the presence of proximity hazards. Consideration should also be given to the projection of the mobile crane beyond the site boundary to avoid potential hazards to the public including those in private areas and public areas.

9.1.2 The owner shall ensure the measures required by the manufacturer of cranes

are implemented, especially the safety measures against falling over, crashing or rolling over of cranes, including, but not limited to, the appropriate use of outriggers and mats / timber blockings to spread out the load.

9.2 Crane standing or supporting conditions 9.2.1 Mobile cranes should only be operated on uniform, level and firm

ground with sufficient load bearing capacity to withstand the maximum in-service loadings of the crane. It should be noted that wind loadings and dynamic effect should also be taken into account.

9.2.2 For the wind effect on structure of mobile cranes, reference can be

made to the Code of Practice on Wind Effects in Hong Kong – 2004 issued by the Buildings Department. Crane manufacturer’s data relating to the dead weight of the mobile crane and the dynamic forces, which can occur during operation of the crane, should always be obtained for determining the maximum in-service loadings.

9.2.3 In calculating the maximum bearing pressures of the crane on the

ground or supporting surface, it is incorrect to assume an average value equal to total weight divided by the ground contact area because the maximum values would generally be far in excess of this average bearing pressure.

or rolliriggers and

9..22 Crane staannddiinn

9.2.1 Mobile cranes .2.1 Mobile crane ground with sufround wit ii i l di

or ssuuppporttiin

ould only be ld oent load bearint loa f th f th

g ccoonditioonnss

operated on uni operated on g capacity to witg capacity to wit

It should be not should be n

propriate u

orm, level am, lehstand the mand thd th t i d d th t i d

d firm d firmimum imum

loadings ings

and maxi

l


25

99 S

iting

of

MMob

ile C

rane

s

Outriggers beams (extended position)

Rear OutriggersFront outriggers

Mat

Float

Fig. 3 Typical mmobile ccrane shown with outriggers set

9.2.4 In order to avoid the sinkage or collapse of the supporting surface and overturning or collapse of the crane, the loading should be distributed over a sufficiently large area. Steel plates of adequate strength, suitable mats or suitable timber blocking should therefore be used.

9.2.5 The owner of the crane shall take appropriate precautions to ensure its stability.

If outriggers are provided, the beams should be fully extended as far as practicable unless otherwise specified by the manufacturer (Fig. 3). The jacks should be suitably extended so that all crane tyres are clear of the ground innormal circumstances. However, in case of lorry-mounted crane, subject to the manufacturer’s instructions, jacking up the tyres clear of the ground may not be necessary.

9.2.6 Some mobile cranes can lift loads with partially extended outrigger beams.

However, use of partially extended outrigger beams should be strictly adhered to the manufacturer’s load charts and requirements because the stability of the crane may be greatly reduced. Where the use of partially extended outriggerbeams is permitted by the manufacturer and cannot be avoided, it should be carefully planned. It should also be supervised by a competent person. In order to prevent confusion in the interpretation of safe working loads, alloutrigger beams should be extended to the same extension positions, unless

Ou(ex

ams amssition)sition)

loatoat

ea s

Fl

26

99 Siting of

MMobile C

ranes

otherwise specified by the manufacturer. In other words, the outrigger beams should not be set at any other intermediate points apart from the designated partial extension positions.

. 9.2.7 Mats or timber blockings with adequate strength and size which are capable of

completely supporting the floats of the outriggers should be used to provide alevel and firm ground support with due regard to the ground condition and having considered the manufacturer’s instructions and assessment of local conditions. If separate pieces of mats and timber blockings are used, they should be tightly spaced. The angles formed between the cylinders and the floats of the outriggers should be maintained to a right angle (90 degrees).

9.2.8 Advice should be sought from the manufacturer regarding the particular

data and information on weights and loadings of the crane. Besides, the supporting surface should be frequently examined during the operation to ensure that there has been no movement or sinkage affecting the crane's stability.

9.2.9 The overall stability and safety of a crane should be carefully checked in

relation to local conditions and particularly when the crane has to be operated on bridge decks, partially completed building frames, other structural supports, or close to excavations and embankments.

9.2.10 When operating close to the edge of a soil slope or an unsupported soil

excavation, a mobile crane may collapse as the load bearing capacity there is much lower than those away from the edge. A safety distance at least 4 times the width of the foundation (the mat or timber blocking of the outrigger or the crawler) should therefore be maintained between the foundation and the edge (see Fig. 4). The distance between the foundation and the toe of the slope or excavation should also be at least 2 times the depth of the slope or excavation. Advice on closer distance from the edge for slopes or unsupported excavation with other materials should be sought from a Registered Geotechnic Engineer.

9.2.11 Before a mobile crane is put into operation in a land filling, reclamation

or demolition site, a thorough investigation on the ground conditions

data and informdata and the supporting upportinoperation to e to eaffecting the cra he cra

9.2.9 The overall stab.2.9 The overall starelation to loca n to looperated on broperated

ure that there that there e's stability. 's stability.

y and safety o nd s onditions and ditio

ge decks, partge decks,

has been no m been

a crane should be crane shoul articularly when articularly wh

ally completed blly completed b

garding the part he part he crane. Bes rane. Besxamined durmined ovement or vement or

carefully che refu the crane ha cra

ilding frameilding fram

g the g thnkage nkage

ked in ked to b to be other other

ring sin

eck as t

es,


27

99 S

iting

of

MMob

ile C

rane

s

Danger area

B : width of foundation

D ≥ 4B D + d ≥ 2H

D d

H : height of slope

Fig. 4 Position of mobile crane

should be conducted to ensure that the crane will not be positioned in areas which have insufficient load bearing capacity.

9.3 Proximity hazards 9.3.1 Consideration should be given to the proximity hazards such as

overhead electricity lines and conductors, power cables, radio frequency wave transmitting tower, nearby structure and building, hoists, stacked materials, other construction works, the flight paths of airfields, the routes of aerial ropeway and other cranes, and public access areas including highways and railways.

H : hH : hheig

Dd

ger are

B : dth of

28

99 Siting of

MMobile C

ranes

9.3.2 As far as possible mobile cranes should be sited to avoid loads being handled over occupied premises, highways, the route of aerial ropeway, other construction works, or railways. The danger to or from underground services, such as gas mains or electric cables, should not be overlooked. Precautions should be taken to ensure that the mobile crane standing is clear of any underground services. Where this is not possible, the services should be adequately protected to safeguard against any damage.

9.3.3 Overhead electricity lines 9.3.3.1 Fatal accident may occur when a crane comes into contact with or near

to overhead electricity lines. Where a mobile crane has a chance of coming within a horizontal distance of 9 meters from the outermost conductor of any live overhead electricity lines, the crane owner should before works are begun, liaise with the owner of the overhead lines, e.g. a power company, to work out the exact safety requirements and devise the safe work plans. Any person working in the vicinity of overhead electricity lines shall observe the relevant provisions on taking all reasonable steps and all reasonable measures as stipulated in Section 10 of the Electricity Supply Lines (Protection) Regulation (Cap. 406H). In particular, a safe working distance must be maintained between any part of the crane and the overhead line conductor. Reference should be made to the Code of Practice on Working near Electricity Supply Lines published by the Electrical and Mechanical Services Department.

9.3.3.2 In ascertaining the safe working distance from the overhead electricity

lines, it should be noted that it would vary with different voltages and operating conditions of the lines. For example, an overhead line may swing laterally due to the wind and its vertical clearance may change due to current loading of the line. Additional allowance should therefore be made to the safe working distance based on the advice from the power company.

9.3.3.3 All overhead lines or other electric apparatus should be treated as live

unless declared dead and safe by the relevant authority. 9.3.3.4 Any person working in the vicinity of any electricity supply line should be

before works arbefore woa power compaer compthe safe work work electricity lines lines reasonable stepe step10 of the Elect ElecIn particular, a ticular, part of the cranpart of th

ns. Any pers Any pers hall observe hall observe

and all reasond all ty Supply Line Supfe working dist work

and the overh and the ov

n working in the rking he relevant prov he relevant p

ble measures as ble measures (Protection) Reg (Protection) nce must be mance must be ad line conductoad line conducto

crane owner s wner s overhead lines rhead lines irements and men

vicinity of o vicinity of osions on tasions on t

stipulated in pulatulation (Cap tion ntained betwned Reference Referen

evise evisrhead rhead ng all ng all

ection ectio 06H). 06H

n any n an hould hould

d d over

akin ki Se

. 40ween e sh


29

99 S

iting

of

MMob

ile C

rane

s

Safety clearance

Fig. 5 Travelling under overhead electric lines and cables

properly trained to ensure that they are capable of taking necessary safety measures.

9.3.3.5 When working parallel to overhead power cables, ground level barriers

or a string of warning markers should be erected at a safe distance from the cables. The position of the barriers should be clearly marked. Warning notices of overhead lines nearby should be attached to or displayed on the barriers at intervals of not less than 2 metres.

9.3.3.6 Where a crane must travel underneath an overhead line, the crossing

route should be plainly marked. Suitable goal posts and crossbars should be erected each side of the crossing approach to ensure that the jib or moving parts are lowered to a safe position (see Fig. 5). In the case where it is not possible to place suitable crossbars due to the width of the passageway, a string of strong non-metallic under tension could be used as a flexible height limiter.

9.3.3.7 The dimensions of the goal posts and crossbars, and their distances

from the nearest power cable are to be decided in consultation with the relevant electric power company. Suitable warning notices should also be erected.

9.3.3.8 The operator of the crane should operate under the direction of a

be used as a flebe used as

afety cle

under tension ension

30

99 Siting of

MMobile C

ranes

signaller who has a clear view of the crane and the obstruction. 9.3.3.9 The signaller should be able to assess whether there is adequate

headroom and clearance. 9.3.3.10 The point of the jib and the front and rear of the crane should be painted

in a distinctive manner for visual sighting and warning purposes. 9.3.4 Proximity of other cranes 9.3.4.1 When considering the positioning of a mobile crane for operation, care

should be exercised regarding the proximity of other cranes. Where overlapping working area(s) cannot be avoided, all the crane operations should be co-ordinated and supervised by a competent person. All the personnel involved including operators, slingers and signaller should be fully informed of the lifting arrangements.

fully informed of fully inform

d signallerer shou shorr


31

110. E

rect

ion,

DD

ism

antli

ng a

nd

Tra

nspo

rtat

ion

10. Erection, Dismantling and Transportation 10.1 General precautions for erection and dismantling 10.1.1 Accidents may occur during crane erection and dismantling operations

due to failure to follow the correct procedures specified by the crane manufacturers, use of incorrect parts, the wrong size or type of bolt, the incorrect assembly or sequence of assembly, or taking apart of components. To avoid dangerous and expensive consequences, the following points should be observed:

(a) it is essential that crane manufacturer's instructions should be strictly adhered to. Any departures from the specified procedures may impose excessive loadings on structural and mechanical parts leading to a failure or collapse of the crane;

(b) the erection or dismantling operation shall be supervised by a competent person who have been adequately trained and have experience of erecting/ dismantling the particular type of crane involved (Regulation 7H of the LALGR);

(c) for the erection/dismantling operation, a roped-off area is required which has been clear of other personnel not involved and stacked materials, etc. The area should be large enough to permit the components to be stacked and handled, and the crane to be erected/dismantled without interfering with or risking the other site personnel. Sufficient area must be set aside for the mobile crane or other lifting appliance that will be used to erect/dismantle the mobile crane. Provisions must be made for good access for trucks delivering or taking away the components. Adequate lighting should be provided for all these working areas;

(d) all major components, particularly those that are load bearing, should be clearly marked for proper identification. Bolts and nuts manufactured from high tensile steel or other special steels should also carry clear identification marks. The re-use of high tensile bolts and nuts should be strictly in accordance with the manufacturer’s specifications and instructions;

y may imposmay imleading to a ding to

(b) the erectio rectiocompetent etent experience rience involved (Rolved

(c) for the ere(c) for

or dismantling or dismantling erson who havon w

f erecting/ dis rectulation 7H of ttion

on/dismantling on/dismant

operation shall operation she been adequatee been adequmantling the partntling the

e LALGR); e LALGR);

operation, a rope peration, a rope

specified proceded proced nd mechanical mechanica

be supervise be supervisy trained an raincular type oar t

-off area is -off area i

parts ar

by a by a have hav

crane cran

required uired

cal

ed ed nd of c

req

32

110. Erection,

DDism

antling and TT

ransportation

(e) all structural components should be inspected to ensure they are free from damage or defects;

(f) erection/dismantling staff should not improvise or try short-cuts in handling the crane. Only the correct tackle and tools should be used;

(g) a copy of the manufacturer’s instruction manual for the particular machine should be carried at all times on the crane (this should bear the manufacturer's machine serial number and the owner's plant number);

(h) assemblies should be slung from the points recommended by the manufacturer and in such a way that they will not swing or become unstable or sustain damage when lifted;

(i) erection/dismantling staff should be fully briefed on and familiar with the prescribed procedures; and

(j) approval should be obtained from the crane manufacturer before any departure is made from the prescribed procedures.

10.2 Folding or hinging jibs 10.2.1 For jib which can be folded down-and-under or hinged sideways, the

manufacturer's instructions should be followed when the jib is setting up for operations or performing jib folding operations.

10.2.2 It should be ensured that the jib is restrained by the hoist rope or other

specified means to prevent it from swinging uncontrollably on release from its stowed position or when pins are removed for folding.

10.2.3 Integral pinned folding-hinges should be provided in the jib sections. 10.2.4 Before erection of the assembled jib, any gate or hinge section should

be positioned or removed in the manner specified by the manufacturer.

(j) approval s approva any depart depart

100..22 Folding oorr hhiin

10.2.110.2.1 For jib which c For jib whf '

ng jjiibbss

be folded dow be foldi hi

n-n-andand-under or h-under or hd be followed whe e followed w

manufacturer bnufacedures. ures

inged sidewged sid h jib i h jib i

before for

s, the s, the etting up g up

er b

ays i


33

110. E

rect

ion,

DD

ism

antli

ng a

nd

Tra

nspo

rtat

ion

10.3 Jib assembly 10.3.1 The following should be noted for jibs which are designed to be

extended by the addition of intermediate sections into the basic jib:

(a) only correct sections for the particular crane should be used;

(b) the sections should be in good conditions and free of bent bracings/main chords, broken welds, etc;

(c) jib length should be made up of at least minimum number of intermediate sections according to the manufacturer's specifications;

(d) sections should be assembled in the correct manner and sequence as specified in the manufacturer's instructions and procedures, and that the bracing pattern continuity is maintained throughout the jib length;

(e) certain designs of jib employing pin connections instead of bolted joints to link jib sections together, the jib should be supported at the appropriate sections according to the manufacturer's instructions. All personnel should never work or pass underneath a jib during this operation. Besides, all the jib section pins should preferably be inserted from the inside of the jib pointing outwards. The suspension ropes or ties should not foul the locking pins or clips of the pin connections when the jib is being raised from ground level. All the locking pins or spring clips should be in good condition and offer effective security of the jib section pins;

(f) other than in accordance with the manufacturer’s instructions, when extending the length of a strut jib no attempt should be made to lift the jib on the suspension. Should this practice be unavoidable, the suspension rope should attach to the extremity of the part-assembled or fully-assembled jib; and

(g) when a fly-jib is to be fitted, the angle and/or length of suspension ties between the fly-jib and the main jib should be in accordance with the manufacturer's recommendations. Also, the safety ropes or arrestors should be installed to prevent backwards instability of the fly-jib.

(e) c certain desertain djoints to lin s to linappropriate priate All personnrsonnthis operat operatbe inserted insertsuspension suspeh i

ections accord ections accord should never ould . Besides, a Bes

rom the insidm th opes or ties shes or t

i h hi h

ng to the manufag to the ma work or pass und work or pass the jib section pe jib sectio of the jib poin of the jib puld not foul the lould not foul the lo

e jib is being rais b is being ra

ns instead of b inste be supporte e supcturer's instrcturer's insterneath a jib eath

ns should pr shouing outward out

cking pins or ing pind f d f

bolted olte at the at thtions. tions.

during durinerably erab The Th

ips of ips of nd level vel

of bed aructruct

b d refe

s. r cli

d

34

110. Erection,

DDism

antling and TT

ransportation

10.4 Jib suspension (see Fig. 6) 10.4.1 Correct length of derricking rope and ties should be used for the jib fitted

according to the manufacturer's instructions. 10.4.2 Longer jibs may require special or auxiliary suspension equipment such

as a high gantry, mast, intermediate suspension, etc. Check should be made for the maximum length of jib which can be raised with the crane as specified by the manufacturer.

10.5 Load hoist rope 10.5.1 The rope system should be strong enough to handle the maximum load

required to be lifted on a jib, and the rope is of sufficient length to perform the load lifting or lowering operation.

10.5.2 Correct type and length of hoist rope as specified by the manufacturer

should be fitted. The steel rope should be made to BS 302: Stranded Steel Wire Ropes or equivalent national standards.

10.5.3 The number of falls of hoist rope according to the jib length or maximum

load to be fitted should be the same as required by the manufacturer. 10.5.4 For the case of an automatic safe load indicator installed, the indicator

cam and/or setting should correspond with the jib length fitted and the number of falls of the hoist rope used.

10.5.5 Not less than two coils should always remain on the drum and the drum

capacity should not be exceeded.

perform the load perform th

10.5.20.5.2 Correct type an ype anshould be fitted fitted Steel Wire Rope Rope

10.5.30.5.3 The number of umber load to be fitted load to b

ength of hoist gth of hois The steel rope The steel rope

or equivalent n equiv

s of hoist rope f ho ould be the sa ould be th

ope as specified as spe should be made should be ma

tional standards. tional standar

according to the j according to thme as required by e as required by

f sufficient lengent leng

by the manu by the man to BS 302: S o BS 302:

b length or m ngth he manufact he manufa

cturer cturer anded anded

imum imumer. er.

ufac Stra S

maxiture


35

110. E

rect

ion,

DD

ism

antli

ng a

nd

Tra

nspo

rtat

ion

Jib

Floating bridle or pulley frame

High gantry or ‘A’ frame (for longer jibs)

Low gantry or ‘A’ frame

Derricking or suspension ties

Derricking rope

Jib safety stop (telescoping)

Jib

Intermediate suspension(may be necessary for longer jibs)

Knee-action backstop

Mask

Derricking or suspension ties

Multi-part derricking rope

Fig. 6 TTypical rope and suspension systems on mobile cranes

b. Suspension with ties(Hoist ropes omittedfor clarity)

c. Mast suspension(Hoist ropes omittedfor clarity)

Fly-jib

Separate rope drums for derricking, auxiliary and main hoist ropes

Pulley hook block for heavy loadsJib safety rope

Fly-jib safety rope

Fly-jib guy (lower)

Auxiliary hoist rope

Fly-jib mast

Light loadsonly

Derricking rope

Fly-jib guy(upper)

Jib

a. Continuous suspension(inclusion of fly-jib is incidentalto type of suspension.)

Main hoist rope

High gantry or ‘AHigh(for longer jibs)(for

Low gantry or ‘A’ Low g f me

(Hoist ropes omitte(Hoist ropes omittedfor clarity)for clarity)

Flo

afety stop (teles

e or pu

36

110. Erection,

DDism

antling and TT

ransportation

10.6 Safety devices 10.6.1 Before the crane is put into use, a check should be made to ensure that

all disconnected or by-passed safety devices such as load indicator, overload cut-out or motion limit switch, etc. during previous erection or dismantling operations have been reconnected and are functioning properly.

10.6.2 Adjustment should be made to the visual load-radius indicator and

automatic safe load indicator each time when the crane condition or front-end equipment is varied. For example, such variation would be for changes in jib length, fly-jib length, falls of hoist rope (main or auxiliary), angle of fly-jib off-set, and also between mobile (on tyres) and with outriggers set operations.

10.7 Crane stability, erection and dismantling procedures 10.7.1 The correct amount of counterweight should be fitted on the crane and

at the appropriate location as specified by the manufacturer's counterweight chart before a jib is elevated.

10.7.2 When additional counterweight for longer booms/jibs are fitted, it should

be removed if the operating length of jib is restored to original length. 10.7.3 For crawler cranes with adjustable track span, retracted tracks for the

sake of transportation should be fully extended during operation. 10.7.4 Erecting or lowering of long jibs should be performed with the jib axis in

the longitudinal axis of the mounting, i.e. in the position offering greatest machine stability. Besides, for the case of crawler-mounted crane operating on a hard concrete surface, wooden packers should be placed under the ends of the crawler tracks to reduce the tendency for the machine to rock during the lowering of long jib to the ground.

10.7.5 Appropriate precautions including the re-setting of auxiliary outriggers

should be taken prior to the lowering of long jibs to the ground.

100..77 Cranee ssttaabbilit

10.7.10.7.1 The correct amct amat the appropppropcounterweight ceight

10.7.210.7.2 When additiona When add

nt of counterwnt of counterwate location locart before a jib i befo

ounterweight f ounterweig

ight should be fitght should b s specified by s specified

elevated. elevated.

r longer booms/ji longer booms/ji

cedduurres

ed on the cred on the c the manufae m

s are fitted, i s are fitted

e and e and urer's urer

hould hould

ane actu

it s


37

110. E

rect

ion,

DD

ism

antli

ng a

nd

Tra

nspo

rtat

ion

10.7.6 The hook block should be lowered and rested on the ground before lowering the jib to ground level in order to maintain the best margin of stability.

10.8 Tyres 10.8.1 For wheel-mounted cranes, lorry-mounted cranes and truck-mounted

cranes which are fitted with pneumatic tyres, check should be made to ensure the conditions of the tyres and that they are inflated to the recommended pressure prior to any lifting operation.

10.8.2 Any replacement tyres fitted should conform to the manufacturer's

specification regarding the size, construction and rating. 10.9 Travelling and transportation 10.9.1 Site travelling with long jib fitted

(a) When it is necessary to travel long jib crane which has been assembled and erected at a remote location to the place of work, it should be handled with great care and under the supervision of a competent person.

(b) The ground to be traversed should be firm and level.

(c) The operation should be performed at creep speeds with the jib in line with the direction of travel and with the slewing locks and/or swing brake engaged. A suitable jib angle to maintain the stability of the crane should be determined before the operation. Reference should be made to the manufacturer’s instructions.

10.9.2 Loading cranes for transportation

(a) When loading and off-loading crawler-mounted cranes and wheel-mounted cranes onto the transporter, care should be exercised when negotiating the deceptively steep ramps onto the vehicle to ensure that the crane does not tip over backwards.

(b) The specified maximum gradient for stability of the crane for transportation should not be exceeded.

100..99 Travelllliinngg aan

10.9.10.9.1 Site travelling wing w

(a) When it is it is assembled embleshould be should competent

long jib fitted long jib fitted

ecessary to tessa nd erected at a erec

ndled with greed wrson rson

avel long jib cra ong jib remote location to emote locatio

t care and under t care and unde

ne which ha whi the place of e pla

the supervise sup

been bee ork, it ork,

n of a n of a

as f wo

sion

38

110. Erection,

DDism

antling and TT

ransportation

10.9.3 Security of crane for transportation

(a) In case that the mobile crane is transported by road, it should be stowed on and securely attached to the carrying vehicle so as to prevent any movement of crane, or any part of it or its equipment during transit.

(b) Additionally, the manufacturer's instructions or recommendations for crane transportation should be followed regarding the restrictions in jib length, jib suspension and counterweights.

10.9.4 General precautions to be taken when transporting cranes

(a) A suitable transporting vehicle of adequate loading capacity and bed dimensions to accommodate the crane should be employed.

(b) The crane's operational brakes and when fitted, propel or digging locks should be engaged and the crane should be fully chocked against all movement.

(c) The crane should be securely lashed to the vehicle to prevent the crane from bouncing, tipping or sliding off the bed.

(d) The upperworks should be cross-chained against possible rotation in addition to setting the swing brake and/or slewing lock of the crane.

(e) Hook block and any other loose items should be securely lashed to prevent any movement during transit.

(f) For the case of truck-mounted crane and lorry-mounted crane, the outrigger beams and floats should be securely stowed and fastened in position to prevent any movement during transit.

(g) It should be noted that the statutory requirements on the movement of cranes on roads under the Road Traffic Ordinance, Cap. 374 shall also be complied with.

locks shoulocks sagainst all ainst al

(c) The crane rane crane from from

(d) The upperw upperin addition additicrane. cra

ould be secureould be secure uncing, tipping cing,

rks should be sho setting the s etting

y lashed to the v lashed to t or sliding off the b or sliding off th

ross-chained aga oss-chained ing brake and/o ing brake an

ed, propel or digpel or diguld be fully cho be fully ch

ehicle to pre ehicle to pre ed.

nst possible pos slewing loc ewin

nt the nt the

tation tatio of the of th

venven

rotk o


39

112. S

afe

Wor

king

LLo

ads

and

oper

atio

n CC

ondi

tions

11. Procedures and Precautions 11.1 Suspension of load 11.1.1 No load is allowed to be left suspended unless a competent person is in

charge of the crane during the period of suspension (Regulation 12A of the LALGR). The operator should remain in the operating position. The machine should be fully operational to meet any emergency arising and with the hoist brake lock, the boom derricking safety pawl and the swing lock/brake, where fitted, all engaged. Under no circumstances should the crane be left unattended with the load suspended.

11.2 Leaving the crane unattended for a short period 11.2.1 A mobile crane should not be left unattended even for short periods

unless the following precautions are adopted:

(a) the load should be removed from the hook;

(b) the hook should be raised to a high position at which it would be safely clear of other operations;

(c) the engine of crane should be stopped and appropriate motions should be braked and locked including those preventing rotation of the upperworks;

(d) the ignition key and any other keys should be removed from the crane and kept by the operator; and

(e) for details of methods to safeguard particular types of cranes, reference should be made to the crane manufacturer’s instructions.

11.3 Leaving the crane unattended for a long period of time 11.3.1 For longer periods of leaving the crane unattended and for out-of-

service conditions, the following precautions should be adopted:

(a) isolation should be more permanent, e.g. switches should be locked

1111..22 LLeeaavviinngg the c

11.2.11.2.1 A mobile crane crane unless the follow follow

(a) the load sh ad sh

(b) the hook se hook safely clea safely

hould not be ould not be g precautions g precautions

d be removed be re

uld be raised be f other operatio f other ope

eft unattended ev nattende re adopted: re adopted:

rom the hook; the hook;

o a high position o a high posits;s;

riod

en for short en for short

at which it w whic

eriods eriods

uld be ld b

pe pe

wou

40

112. Safe W

orking LLoads and operation

Conditions

off, fuel supplies cut off and any doors giving access to machinery or control cabins should be locked to prevent unauthorized access;

(b) the jib should be secured or lowered according to the manufacturer's instructions for out-of-service conditions;

(c) if it is not possible to lower the jib due to space restrictions, the hook block should be lowered near to ground level and secured to a substantial anchorage vertically below the jib point;

(d) the ignition key and any other keys should be removed from the crane; and

(e) for details of methods to safeguard particular types of cranes, reference should be made to the manufacturer's instructions.

11.4 Routine Checks 11.4.1 At the beginning of each shift or working day, the operator, if competent

for the purpose, or a competent person, should carry out the following routine visual inspection, as appropriate:

(a) checks as required by the manufacturer’s instructions;

(b) check that the automatic safe load indicator is correctly set and that the manufacturer’s daily test is carried out;

(c) check that the correct load-radius scale appropriate to the jib (or fly-jib) length is fitted on the visual indicator;

(d) check the levelling of the crane to confirm that there has been no change in the original levelling, no sinking of outrigger floats or settling of the foundation;

(e) check the security of the counterweight or ballast where this is in the form of removable weights, check that the weights fitted correctly correspond to those shown on the counterweight chart for the operating condition [Note: Where the stability of a crane is secured by means of removable weights, a diagram or notice indicating the position and amount of the weights shall be affixed to the crane in a place where it can easily be seen (Regulation 7F of the LALGR);

(f) check the oil level(s), fuel level and lubrication;

11.4.11.4.1 At the beginning eginninfor the purpose rpose routine visual inual in

(a) checks as ks as

(b) check that heck ththe manufathe m

r a competent r a competent ectiontion, , as appras app

uired by the med b

e automatic saf utomurerurer’’s daily test s daily

person, should cson, shoupriatepriat :

nufacturer’s instrfacturer’s in

load indicator is load indicato s carried out; s carried out;

perator, if coator rry out the f rry out the

ctiononss; ;

correctly set rectl

petent peteowing owing

d that d tha

mp follo follo

and


41

112. S

afe

Wor

king

LLo

ads

and

oper

atio

n CC

ondi

tions

(g) check hook for signs of obvious wear and damage;

(h) check the ropes, and rope terminal fittings and anchorages for obvious damage and wear;

(i) check the condition and inflation pressure(s) of tyres (where applicable);

(j) check that all water is drained from any air receivers;

(k) check the jib structure for obvious damage;

(l) check the operating pressures in any air and/or hydraulic system(s);

(m) check leakage of brake fluid and hydraulic oil;

(n) check the operation of the crane through all motions with particular attention to brakes to ensure that these are operating efficiently;

(o) check the operation of all limit switches or cut-outs (use caution in making the checks in case of non-operation); and

(p) for safety and to prevent the risk of fire, the crane cabin is in a tidy state, is free from tins of grease and oil or other fluids; from rags, tools, shackles, and other materials, and that a fire extinguisher suitable for extinguishing both electrical and other types of fire is available in a convenient place in the crane cabin.

11.4.2 At least once a week a full inspection of the crane shall be carried out by

a competent person. Apart from those items under section 11.4.1 covered in the daily inspection, attentions should also be paid to all anchorages, fixing and structural members. The check should include identifying of significant cracks and flaking of the paint on structural members and joints, which are usually signs of permanent deformation and loose joints. Bolts should be checked for tightness and welded joints inspected for visual cracks. Check the slewing rings, slewing gears and gusset plates in the mobile ring for defect. This section of the crane takes the direct torsion load of braking and acceleration of the slewing motions which constitute a high proportion of the crane's duty cycle; further, the load is a cyclically reversing head, the worst possible condition for producing fatigue failures. The competent person should also check for any abnormal noise while the crane is in motion as this is usually the sign of crane damage.

making the ma

(p) for safety ar safety state, is fre, is fretools, shac shacsuitable fo le fo available in able i

11.11.44.2.2 AtAt least once a least o

from tins of grm tins of ges, and other s, and other

xtinguishing bnguis convenient planven

ek a full inspecek a full in

ase and oil or ot and oil materials, and tha materials, and

th electrical and h electrical ae in the crane cae in the crane

ion of the crane son of the crane s

( nd

ane cabin is cabher fluids; froer fluids; frot a fire extint a fire ext

other types oer tyin.

hall be carrie hall be carr

a tidy a tid rags, rags, uisher uisher fire is fire

out by out by

in a om

ngu of f

ed o

42

112. Safe W


Conditions

11.4.3 Use of "Checklist" for carrying out the above mentioned routine checks is recommended. A certificate in an approved form stating that the mobile crane is in safe working order shall be submitted to the owner by the competent person when no defect was found in the weekly inspection.

11.4.4 Should the person carrying out an inspection find any defect (such as

twisted/broken wires, etc.) or abnormality in the mobile crane or in the operation of the mobile crane, or should the mobile crane be accidentally damaged, this should be reported immediately to the person responsible for the safe use of the crane. The machine should be taken out of service until the faults have been rectified and clearance is given by the person responsible for the safe use of the crane. Sufficient space on the "Checklist" for reporting the defects are recommended.

11.4.5 The competent person responsible for the inspection of a mobile crane

or any lifting gear should have the responsibility to ensure the mobile crane or the lifting gear under his responsibility has received proper regular inspection according to the schedule set under the safe system of work. He should record the state of every mobile crane or lifting gear. He should ensure that a mobile crane or lifting gear is withdrawn from service should he reveal in the inspection that it is not in safe working order. In particular, the competent person responsible for the inspection of the mobile crane or lifting gear should:

(a) have attained the age of 18 years;

(b) be an experienced mechanic;

(c) have properly trained in crane operation and crane maintenance;

(d) be familiar with hazards, limitations and safety precautions associated with crane operation;

(e) be familiar with the servicing or repairing requirements and limitations as defined in the operation and maintenance manuals of the cranes under his responsibility;

(f) be familiar with the provisions related to the use of mobile cranes in the LALGR and the contents in this Code; and

(g) be capable of performing simple tests in accordance with the

11.4.51.4.5 The competent ompetenor any lifting ge ting gcrane or the lif he lifregular inspectipectiof work. He s He gear. He shou He shfrom service shfrom ser

should have ould have g gear under g gear under according to t corduld record the rec ensure that a sure uld he reveal uld he rev

he responsibility sponsi his responsibility is responsibi

e schedule set ue schedule se state of every m tate of ever

obile crane or lift obile crane or n the inspection the inspection

on of a mobi of a o ensure the ensure th has received has receive

nder the safe r the obile crane oe crng gear is wi gea

hat it is not hat it is n

crane cran mobile mobile proper proper ystem yste

lifting liftindrawn draw

safe safe

le ce m d pd e sy or

ithd in


43

112. S

afe

Wor

king

LLo

ads

and

oper

atio

n CC

ondi

tions

manufacturer’s instructions. 11.5 Permit to work for maintenance 11.5.1 Before any major repairs, adjustments or inspections are carried out on

a crane, a proper system of granting permission to work should be considered. Such a permit to work system properly implemented will ensure that the necessary precautions are taken to make the crane safe for maintenance or repair work, etc. (e.g. by isolation and lock-off of electrical equipment, removal of ignition keys, etc.) and will notify all affected persons that the crane is out of service.

11.5.2 A permit to work is a specially designed form issued only by the person

responsible for the safe use of the crane. It indicates that special precautions have been taken to make it safe for work on the machine to proceed for a specified period of time. The form should also specify any additional precautions which should be observed by persons carrying out the work.

11.5.3 Most system requires that the person performing the work should retain

the permit in his possession while carrying out this work. Where several persons are involved on the same job, the permit should be held by the senior person (e.g. a foreman). A commendable practice in this respect is for the permit to be placed in a specially designed carrier (e.g. weatherproof transparent plastic jacket) and displayed in a prominent position on the crane involved, such as on the access door or at the crane operator's station, to indicate that persons are working on the machine.

11.5.4 When the work is completed, all permits should be returned to and duly

endorsed by the person who issued them before the crane is ‘handed over’ for normal use. This procedure is as important as the original certification. The person responsible for the safe use of the crane should ensure that all persons who worked under the permit are clear of the machine or area. He should also ensure equipment that was brought in for the work is removed, all safety guards on the crane are replaced and the machine is in all respects safe for normal use, subject

precautions havprecautionproceed for a sed for a any additional tional carrying out the ut the

11.5.31.5.3 Most system retem rethe permit in ermit i several persons several p

ecautions whutions wh ork. ork.

res that the pes tha possession w osse

re involved on re involved

ch should be oould

son performing tson performin hile carrying ou hile carrying he same job, the e same job, the

dicates that sp that srk on the machi n the machi should also ould served by served by

e work shou work this work. s w

ermit should ermit shou

pecify pecirsons rsons

retain reta Where Wher e held e held

o sp per p

uld r Wd be

44

112. Safe W


Conditions

to the conditions specified in section 14 of this Code. 11.6 Safe means of access 11.6.1 Provision should be made for safe access to the crane cabin or any

other areas necessitating periodic maintenance, inspection, or adjustment purposes.

11.6.2 Only the crane operator or the person being authorized should be

allowed to climb on the crane in order to gain access to the cabin or to carry out tasks such as maintenance or inspection.


45

112. S

afe

Wor

king

LLo

ads

and

oper

atio

n CC

ondi

tions

12. Safe Working Loads and Operating Conditions 12.1 Mode of operation and control 12.1.1 Each crane control shall be clearly identified to indicate its purpose and

the mode of operation (Regulation 16(2)(b) of the LALGR). When practicable, the crane control shall also be provided with suitable spring or other locking arrangement to prevent accidental movement or displacement (Regulation 16(2)(a) of the LALGR).

12.1.2 Before starting any lifting operation with a crane, the operator should

ensure:

(a) that he has a clear and unrestricted view of the load and operational area; if not, he should act under the directions of an authorized signaller who is positioned to have such a clear and uninterrupted view;

(b) where telephone or radio communications are being used, that the calling signal is functioning and that verbal messages can be clearly heard; and

(c) that all gauges are reading correctly and that air or hydraulic systems are up to operating pressure.

12.1.3 Handling of loads near persons

12.1.3.1 When loads have to be handled in the vicinity of persons, extreme care should be exercised and adequate clearances should be allowed.

12.1.3.2 Lifting of loads over highways, railways, or other places to which the public have access should be avoided.

12.1.4 Slewing/travelling clearances 12.1.4.1 Where a crane having a travelling or slewing motion is in use, an

unobstructed passageway, not less than 600 millimetres wide, shall be

(a( ) that he h) that he operationa erationaauthorized rized uninterruptrrupt

(b) where telepe telecalling signling siheard; heard and

gnaller who is gnaller who is view; ew;

one or radio coe or s functioning a unct

positioned to hasitioned to

mmunications are munications nd that verbal mes nd that verbal

w of the load f the load the directione dire such a cle such a c

being used, ng usages can be ges c

and an of an of ar and r and

at the at th learly lear

oad ns

ear ear

tha e c

46

112. Safe W


Conditions

maintained between any part of the crane liable so to move and any nearby guard rail, fence or other fixture (Regulation 8 of the LALGR).

12.1.4.2 Where it is not practicable to maintain such clearance or where only

limited slewing or travelling motion of the crane is possible, special precautions should be taken to avoid a trapping hazard:

(a) personnel should not be allowed to approach near a crane when it is operating or travelling as there is a danger of being struck or trapped between fixed and moving parts of the crane;

(b) ''Keep Clear ' notices in English and Chinese which are

visible from the sides and rear of the machine should be painted on the slewing upperworks;

(c) for safety awareness purpose, the counterweight or rear-end of the crane should be painted distinctively (e.g. striped high visibility yellow and black); and

(d) a further notice in English and Chinese should also be displayed on the crane to the effect:

'NO PERSON IS ALLOWED ACCESS TO ANY PART OF THE CRANE

WITHOUT THE PERMISSION OF THE OPERATOR

, '.

12.2 Safe working loads 12.2.1 The safe working load of a crane is defined in the LALGR as the

appropriate safe working load for operating the crane as specified in the current certificate of test and thorough examination delivered in the approved form by a competent examiner in respect of that crane (Regulation 3(1) of the LALGR). In other words, the safe working load is the maximum load under specified conditions for which a crane can lift safely.

12.2.2 Mobile cranes and their associated lifting gear shall be clearly marked

with their safe working loads. Means of identification shall be provided (Regulations 11(2) and 18 of the LALGR).

yellow and yellow

(d) a further nourther nthe crane to rane t

'NO PEERRSSOO

WITHOOUUTT TTH

he effect: e effec

IS AALLLLOOWED A

PERRMMIISSSION O

,

CCCCEESSS TOO AANNY P

THE OOPPEERRAATTOOR

triped high vis high vis

also be displo be

ARTT OOFF THE

''..

ed on ed o

RRAANNE

laye

E C


47

112. S

afe

Wor

king

LLo

ads

and

oper

atio

n CC

ondi

tions

12.2.3 Safe working loads apply only to freely-suspended loads. Before lifting a load the hoist line should be plumb. Using the crane hook or slewing motion of a crane to drag any load along the ground, etc should be forbidden. Similarly, sideward pushing/pulling the load whether with bare hands or by chain block/s or by similar equipment should be discouraged. Failure to observe these points may endanger the stability of the crane or introduce loadings (stresses) into the jib for which it has not been designed. Even with an automatic safe load indicator fitted, a structural failure may result without any prior warning being given.

12.2.4 In case a mobile crane is used to drag a load not in a vertical direction,

steps shall be taken to ensure that no undue stress is imposed on any part of the structure or mechanism of the crane thereby endangering the stability of the crane and such use is supervised by a competent person (Regulation 15(1) of the LALGR).

12.2.5 Reference should always be made to the crane manufacturer's manual

of appropriate machine specification to establish the restriction, limitations or special conditions applicable to a particular crane.

12.2.6 Only the correct table of safe working loads appropriate to the design

capacity of the jib, the counter-weight fitted and the specification of the mounting should be used.

12.2.7 Due to the variations in the weight of the hook blocks and slings which

can be used on mobile crane lifting operations, the weight of the hook block and slings should be considered as part of the safe working load.

12.2.8 Allowance on the safe working load should be made according to the

manufacturer's instructions when auxiliary equipment such as fly-jib or additional lifting attachments are used.

12.2.9 When working at depths below ground level, the actual loading of the

crane is affected by the weight of the long hoist rope. The weight of the hoist rope should therefore be taken into consideration of the safe working load.

12.2.10 Working at extremes or reach of safe working load should be avoided

12.2.52.2.5 Reference shouence shof appropriate priate limitations or sp or sp

12.2.62.2.6 Only the correc correcapacity of the ty of thmounting shoul mounting

machine spechine specal conditions aal conditions a

able of safe we of the counter-w e co

e use e used.d.

cation to estabn to plicable to a part plicable to a p

rking loads apprking loads aeight fitted and theight fitted and

anufacturer's factuish the ressh the re

cular crane. cular crane.

opriate to the ate e specificatio pecif

anual anuction, ction,

esign esig of the of th

mastri

e don o

48

112. Safe W


Conditions

wherever possible. 12.2.11 The crane should be positioned in the most favourable position so as to

operate with as short a jib as possible and at a mid-radius position. 12.2.12 The safe working load at any given radius generally varies with jib length

and any extension in jib would reduce the safe working load. 12.2.13 Derricking-out the jib to increase the radius of the load would generally

result in a reduced lifting capacity. 12.2.14 The load-radius dimension is the radius of the hook with the safe

working load suspended, unless otherwise specified. When a load is picked-up, owing to the stretch of the guy ropes of loaded jib and/or deflection of the jib structure, the hook radius will increase. With the approach of maximum safe working load, this increase may take the load outside the permitted radius. Before the lift is made, the jib should be derricked-in to bring the load back into radius, as necessary (see Fig. 7). Conversely when settling down loads with the jib positioned at steep angles, it should be ensured that the jib is not damaged by extreme tensioning in the jib guy ropes. Sudden settling-down or release of loads should always be avoided in order to prevent the jib springing backward or the machine becoming unstable in a backward direction.

12.2.15 Fierce movements of any operational control even without a load on the

hook should be avoided because these could be dangerous and damaging to the structure or machinery of the crane.

12.2.16 For cranes fitted with long jibs (and particularly extended telescopic jibs)

at large radii, the influence on overturning moment due to the weight and dynamic effects of the jib itself would be very large by comparison with that due to the suspended load. Therefore, the operational controls such as the jib derricking control should be operated sensitively and smoothly.

12.2.17 Zone of operation for cranes

approach of mapproach load outside the utside tbe derricked-in ked-in 7). Conversely ersely steep angles, les, extreme tensio tensiorelease of loade of lospringing backwspringing

bring the load g the load when settling when settling should be ensould

g in the jib in t should always uld rd or the machrd or the m

ack into radius, a nto rad own loads with own loads w

ured that the jib red that the uy ropes. Suddy ropes. S be avoided in ord be avoided in

ne becoming unne becoming un

increase. Wit e. Witrease may tak e may tak

made, the jib de, necessary ( necessary he jib positi he jib posi is not dama not en settling-d seter to preven to ptable in a batable in a

hould houe Fig. e Fig. ed at ed at ed by ed bwn or wn o

he jib he jikward kward

b sh (see ioneagedownt th

ack


49

112. S

afe

Wor

king

LLo

ads

and

oper

atio

n CC

ondi

tions

(a) Cranes would usually be restricted to different duties over the front, rear-end or sides of the crane. The lifting or movement of loads over the front of the crane may overload the front axle(s) or chassis frame owing to the weight distribution of the machine. The safe working load applicable to the zone of operation should be observed.

(b) In some instances, operation of the hydraulic cranes with telescopic jibs should be restricted to the blocked condition with outriggers set and free-on-wheels duty may not be permissible (see sub-section 6.2.6).

(c) Reference should be made to the manufacturer's manual for details of restrictions.

12.2.18 Where a means for locking out or reducing the spring effect of the

suspension is used during crane operations for truck-mounted crane and lorry-mounted crane, the manufacturer's instructions should be followed in respect of its use.

suspension is suspens lorry-mo

followed in resp in resp

p g ruck mounted c

tructions shoulction ld be bhoul

50

112. Safe W


Conditions

CHECK THE LOAD RADIUS DURING OPERATION The figure shows the effect on radius when picking-up or setting down loads due to stretch in jib suspension ropes, jib and machine deflection. Where necessary re-adjust the radius after lifting the load just clear. Always place loads gently. Otherwise the jib may collapse or be damaged.

Fig. 7 Influence of rope stretch on board operation


51

112. S

afe

Wor

king

LLo

ads

and

oper

atio

n CC

ondi

tions

12.3 Near maximum working loads 12.3.1 When handling load which approaches the maximum working load for

an operating radius (95% - 100%), crane motions should be operated with extreme care. The load should initially be lifted just clear of the supporting surface and brought to rest in order for the slings, balance of the load, etc., are checked before proceeding further. Proper care should be exercised by the operator, at all times, to avoid shock or side loadings on the jib. Care should also be taken to avoid the hook contacting the jib head structure, either through overhoisting or when derricking out the jib. In the latter case, as the jib is derricked out the hook should be lowered off in order to maintain an adequate clearance between the hook and jib head structure.

12.3.2 The safety precautions regarding the operations near maximum working

loads are as follows:

(a) the weight of the load should be ascertained as reliable as possible, for example, by the use of a proving ring or other means before lifting the load;

(b) a trial lift should then be made to check the operational stability by raising the load just clear of the ground and at a radius corresponding to the maximum radius at which the load is to be handled;

(c) the load should then be placed on the ground to check if adjustments to the outriggers, slinging and radius are required prior to the final lift;

(d) the operator should exercise proper care to avoid shock or side loadings being imposed on the jib; and

(e) any automatic safe load indicator fitted should not be solely depended upon and only be used as a check that the load is within the capacity of the crane.

12.4 Travelling with suspended loads 12.4.1 Travelling with suspended loads should be handled with great care and

12.3.212.3.2 The safety prec The safety loads are as fol are as f

(a) the weight eight for examplampllifting the lo the lo

(b) a trial lift sh rial lift raising the raising

d

the load should he load should by the use of the use of ;

uld then be ma then oad just clead jus

h i h

be ascertained a ascertain a proving ring or a proving ring

e to check the oe to check thr of the groun r of the groun um radius at wh radius at

ar maximum wo aximum wo

reliable as p reliable as other means er m

perational staation and at a and a h h l d h h l d

ssible, ssible, before befor

ity by ity b adius adius

is to be be

pos poss b

abil a r

i

52

112. Safe W


Conditions

under the supervision of a competent person. 12.4.2 Safe working loads appropriate to free-on-wheels or mobile operation

should not be exceeded when travelling with suspended loads. 12.4.3 Any special restrictions imposed by the manufacturer should also be

followed. 12.4.4 The operation should be performed at creep speeds with the jib in line

with the direction of travel and with the slewing locks and/or swing brake engaged. A suitable jib angle to maintain the stability of the crane should be determined before the operation. Reference should be made to the manufacturer’s instructions.

12.4.5 The load should be carried forward in case of crawler-mounted or

wheel-mounted cranes. 12.4.6 The load should be carried at the rear of the truck in the case of truck-

mounted cranes (see sub-section 12.2.17). The crane operator should remain in the crane cabin to control the load and a second person should be deployed to drive the vehicle.

12.4.7 In general, travelling acceleration, slewing motions and braking action

should be operated gently to limit the swing of the load. 12.4.8 Steady lines should be attached to the load which in turn should be

carried as near to the ground as possible to prevent pendulum motion. 12.4.9 Ground preparation 12.4.9.1 The ground to be traversed should be prepared to ensure a firm and

level access route for the crane where necessary. 12.4.9.2 To prevent the crane tilting laterally or in the direction of travelling,

ground depressions or pot-holes if any should be filled. 12.4.9.3 Mats or other suitable travelling surfaces should be laid where sinkage

of the wheels or crawlers could occur in soft ground.

wheel-mounted wheel-mo

12.4.62.4.6 The load should shoulmounted cranes ranes remain in the the should be deplo e depl

12.4.7 In general, trav12.4.7 In gener

e carried at thrried at t see sub-sectio ee sub-sectio

ne cabin to c cabd to drive the v o dri

ng accelerationg accele

rear of the truck of th 12.2. 12.2.17).) The cThntrol the load antrol the load

ehicle. hicle.

, slewing motion slewing motion

crawler-mountemoun

in the case o the c rane operato ane operat

nd a second a se

s and brakin s and brak

truck- truck hould hould

ererssono

action action

of tor s d pe

g a


53

112. S

afe

Wor

king

LLo

ads

and

oper

atio

n CC

ondi

tions

12.4.10 Slopes 12.4.10.1 Mobile cranes travelling with suspended loads should avoid to travel on

slopes wherever possible. 12.4.10.2 If unavoidable, a competent person should be consulted for the

precautions prior to the negotiation and in attendance to advise on the feasibility of the operation. The following points should be particularly noted:

(a) for safety sake, any crane used in the negotiation of slopes should have a generous margin in capacity over the loads to be lifted;

(b) the load should always be carried on the uphill side of the crane, irrespective of the travel direction;

(c) the load should always be placed on the uphill side of the crane and precautions taken to ensure that neither the jib nor crane become unstable on release of the load;

(d) the load should always be carried as near to the ground as possible;

(e) the swing brake and/or slewing lock should be engaged during the negotiation;

(f) no slewing should be allowed except to maintain the load in the uphill direction;

(g) before starting up a gradient by a crawler-mounted crane, digging locks, where fitted, should be engaged in the position to prevent the crane from running backwards. The digging locks should be engaged again when arriving at the working location to prevent any movement of the crawlers before shifting the clutch from travel to slew; and

(h) a suitable jib angle to maintain the stability of the crane should be determined before the operation. Reference should be made to the manufacturer’s instructions.

12.5 Carrying of persons by crane 12.5.1 A crane can only be used to carry persons where the use of a builder’s

(c(c) the load sh) the loprecautions ecautiounstable on able o

(d) the load shod sho

(e) the swing b wing neggotiation otiatio

(f)(f) no slewing no s

elease of the lose of the lo

d always be ca lways be ca

ke and/or slew and

hould be allow hould be a

d;

ried as near to thried as near to

ng lock should be lock should

ed except to maid except to mai

side of the crane of the crane b nor crane or c

e ground as p oun

engaged du gag

ntain the loa tain the lo

come com

sible; sible

ng the g th

n the n the

bec

pos

urin

d i

54

112. Safe W


Conditions

lift, a tower working platform or a suspended scaffold is impracticable. The carrying of persons by a crane is subject to certain statutory requirements which include:

(a) the person shall be carried in a chair, cage, skip or other receptacle at least 900 mm deep, the receptacle is of good construction, sound material and adequate strength, and is provided with suitable means to prevent any occupant from falling out and does not contain material or tools liable to interfere with his hand hold or otherwise endanger him;

(b) suitable measures are taken to prevent such chair, cage skip or other receptacle from spinning or tipping in a manner dangerous to any occupant;

(c) if a hook is fitted to the lifting appliance, it is so designed and maintained as to prevent the accidental displacement of such chair, cage, skip or other receptacle from the hook; and

(d) where the person is carried in a boatswain’s chair or other similar plant or equipment less than 900 mm deep, a suitable safety belt attached to an independent lifeline should be provided to and worn by the occupant and the lifeline should be securely suspended.

(Regulation 18B of the LALGR)

12.5.2 The receptacle should also be so designed that in case of falling or failure of the receptacle:

(a) the occupant will not be trapped between any part of the receptacle (including the sling) and the safety belt or the lifeline; and

(b) no part of the receptacle will give rise to a serious bumping hazard to the occupant.

12.6 Communication system 12.6.1 In the interests of safety, a standard signalling code (see Table 1) may

be adopted. It is recommended that copies of the signal code shown in Table 1 be issued to all crane operators, slingers and any other persons concerned.

cage, skip cage,

(d) where the ere the plant or eq or eqattached to ed to by the occue occu

(Regulation 18B tion 1

pment less thament less tha n independent ndependent

nt and the lifel and

f the LALGR) e LA

900 mm deep, 00 mm de feline should be feline should ne should be secuuld be s

ement of such c f such nd

chair or othe ir or a suitable sa a suitable sa provided to avided

rely suspendy sus

imilar imilay belt y belt worn wor. .

er s fety fety

nd ded


55

112. S

afe

Wor

king

LLo

ads

and

oper

atio

n CC

ondi

tions

12.6.2 In certain situations and where special lifts are involved, it may be necessary to supplement the hand signals by other forms of communication such as radio, walkie-talkie or telephone.

12.6.3 If tele-communication equipment such as radio or walkie-talkie is used

in a multi-crane situation, suitable arrangement should be made to ensure that the radio frequency is not interrupted for whatever reason at any time during the crane operation period and correct message is received by persons using such equipment.

12.7 Weather conditions 12.7.1 Cranes shall not be used under weather conditions likely to endanger its

stability or affecting its safe operation. Before a crane is taken into use after exposure to weather conditions likely to have affected the stability of the crane, the crane's anchorage or ballast, where applicable, shall be tested by a competent examiner (Regulation 7G of the LALGR).

12.7.2 Any instructions issued by the crane manufacturer advising conditions

under which a crane should be taken out of service and recommending the conditions in which it should be placed should be strictly followed. During adverse weather conditions such as rainstorm and lightning, adequate precautions should be taken to prevent personnel associated with the use of the crane from being endangered.

12.7.3 Cranes are generally designed to operate in conditions of normal steady

wind speed and should not be operated in wind speeds that are in excess of those specified in the operating instructions for the crane. Gusty wind conditions may have an adverse effect on safe working loads and machine stability. Even in relatively light wind conditions it is prudent to avoid handling loads presenting large wind-catching surfaces. The large surfaces might result in loss of control of the load or overturning of the crane despite the dead weight of the load being within the normal working capacity of the machine.

12.7.4 Where a load has a large surface area in relation to its weight, for

example a large timber shutter or panel, the action of the wind or the

after exposure after expoof the crane, th crane, be tested by a c by a c

12.7.22.7.2 Any instructions ctions under which a cich a the conditions inditionDuring adverse During a

mpetent examintent exami

ssued by the ced bne should be t sho

which it should ch i weather condit weather co

er (Regulation 7G egulatio

ane manufacture ane manufac ken out of servicken out of se

be placed should be placed shons such as rainns such as rain

ane is taken into ken in affected the stacted the staere applicab app

of the LALGR of the LALG

r advising co dvisie and recomm nd re be strictly f e strstorm and listorm and

shall sha

itions itionnding ndinowed.owed tning, tning,

ble, R). )

ondmen

follo ight

56

112. Safe W


Conditions

load may give rise to unsafe working conditions in respect of the strength or stability of the crane, or because the load cannot be adequately secured against swinging or spinning; with some loads this can occur at wind speeds below that specified for in-service conditions. Under such circumstances the size of the load should be limited to that which can be safely handled by the crane and which will not create unsafe conditions for operatives. Furthermore, a tag line or control rope should be used for assisting in the control of the swing or rotation of the load.

12.7.5 Name boards or other items presenting a wind catching area should not

be fitted to the jib of a mobile crane without the express approval of the manufacturer.

12.7.6 Before a lifting operation is started, information on wind conditions

should be obtained through the weather forecast to ensure the wind speed limit specified by the manufacturer is not exceeded.

12.7.7 Any lifting operation should be stopped and the mobile crane should be

secured in an appropriate out-of-service condition whenever the wind speed limit specified by the manufacturer is exceeded.

12.8 Mobile cranes for other duties 12.8.1 General 12.8.1.1 A mobile crane should not be used for piling operations, grabbing,

magnet service or any other duty which might impose excessive and/or indeterminate loadings onto the crane structure unless it is also designed for such operation. Reference should also be made to the manufacturer’s manual on the limitations and conditions where such operation can be used.

12.8.1.2 Working loads are often required to be reduced in accordance with the

duty conditions of a mobile crane to be used for such duties. Manufacturer's recommendations should therefore be strictly followed for each specific usage.

should be obtashould be speed limit spec limit sp

12.7.72.7.7 Any lifting opera operasecured in an an speed limit spec mit spe

1122..88 MMoobbiillee crane

on should be sn should be spropriate out-priat oed by the manu by th

oorr ootthheerr ddutie

opped and the mopped and the -service condition service condacturer is exceedacturer is exc

ss

on wind condd cond to ensure the ensure the eeded. ed.

bile crane shbile crane s whenever t heneed.

uld be uld be wind win

hou h the


57

112. S

afe

Wor

king

LLo

ads

and

oper

atio

n CC

ondi

tions

12.8.2 Piling Service 12.8.2.1 Piles are usually driven into the ground by means of an impact or

reciprocating hammer. Bored-pile techniques, with or without casings, may also be used whereby the pile is cast in its location by pouring concrete into a hole driven or bored into the ground. Piling operations, on occasions, are to withdraw or extract the pile (or pile casing) once their useful purpose has been served.

12.8.2.2 Piling service necessitates the use of special equipment. Depending

on the type or sophistication of piling, this equipment may either be in the simple form of a temporary attachment to a crane or, at the other extreme, may form a permanent special-purpose installation on a machine.

12.8.2.3 For pile extraction, an extractor, which is usually of reciprocating or

vibratory type (and may be used either for driving-in or pulling-out piles) strikes the pile upwards and loosens its adhesion in the ground. The actual pull to withdraw the pile is done by the hoist line from which the extractor is suspended. Extraction should be effected by a ‘smooth’ pull on the hoist line and under no circumstances should the hoist rope be jerked, the jib be swung or the machine be tipped to achieve faster results.

12.8.2.4 In assessing the required capacity of a crane for pile extraction duty, in

addition to the weight of the extractor and pile, account should be taken of the frictional forces occurring between the soil and the pile during extraction, and the induced vibrating effect of the load. In the case of sheet pile extraction a further allowance is necessary for the friction between the clutches of the pile being extracted and the adjacent pile remaining in the ground. As the frictional effects are largely unknown factors, until extraction commences, the largest crane on site with ample safety allowance available will always give the safest and quickest results providing the pull does not exceed the extractor rating.

12.8.3 Grabbing and magnet crane service 12.8.3.1 When using cranes for grabbing or magnet crane service, allowance

12.12.8.28.2.3.3 For pile extrac For pile evibratory type (aory type strikes the pile e pile actual pull to w to wextractor is sus s suspull on the hois e hoibe jerkedked, the j, thresults. results.

wards and loods and loodraw the pile i draw the pile i ended. Extraced.

ne and under and be swu swung or th

ens its adhesion ts adh done by the hois done by the

on should be efon should be o circumstances circumstanc

e machine be tipe machine be

y of reciprocatin reciprocatinn or pulling pul -o in the groun n the grount line from wt line from wected by a ‘ed b

should the hould ted to achiev to a

piles) piles The Thch the ch the mooth’ moott rope rop faster faste

out nd.

whic hi ‘sm

oist ve f

58

112. Safe W


Conditions

should be made not only for the weight of the grab, magnet or other attachments, together with load, but also for additional loadings imposed on the crane resulting from fast slewing, grab suction effects, impacts, etc. In general, for grabbing or magnet crane service the weight of the grab and contents, or the weight of the magnet and load will be less than the corresponding safe working loads for crane service. Reference should be made to the manufacturer's specification for details of special duty ratings.

12.8.4 Tandem Lifting by mobile cranes 12.8.4.1 Lifting a load with two cranes is a potentially dangerous operation which

should be avoided except where the physical dimensions, characteristics or weight of the load prevent this being handled by a single crane. There are statutory requirements governing the lifting operation in which more than one crane is used (Regulation 7І of the LALGR). Tandem lifting requires extremely careful planning and an accurate assessment of the share of the load which is to be carried by each crane. There should be a full appreciation of how and to what extent this can vary should the load come out of level or should one or both cranes have to derrick, travel or slew, resulting in the hoist ropes coming out of plumb.

12.8.4.2 If any of these circumstances occur an additional load can be thrown on

either or both cranes which may affect crane stability or cause a structural collapse.

12.8.4.3 Special lifting tackles may be also necessary to suit the maximum

variation in load distribution and direction of application which can occur during tandem lifting.

12.8.4.4 All tandem lifting operations should be thoroughly planned in advance

by a competent person. Where possible cranes of equal capacity and similar characteristics should be used. The cranes and lifting tackle to be used should be selected to have a capacity margin greater than that needed for the proportioned load when handled as a single lift.

12.8.4.5 A competent person should be specially appointed to supervise the

operation in whoperation LALGR). TandR). Taaccurate asses asseseach crane. Te. Textent this can can both cranes hanes hacoming outg out of p o

ent of the sha of the share should be re should be ry should the l shou to derrick, tra derr

mb.

e of the load whic he loa full appreciation full apprecia ad come out of lead come out

el or slew, resultil or slew, res

governing the ng the Regulation 7І o ulation 7І o

ful planning planh is to be cah is to be ca

of how and of how and vel or should or s

ng in the hoi n th

nd an nd aed by ed by

what what ne or ne o ropes rope

an arrie

to d ost r


59

112. S

afe

Wor

king

LLo

ads

and

oper

atio

n CC

ondi

tions

operation, and the signals to each crane operator should be clear and well rehearsed.

12.8.5 Other special uses of hydraulically driven mobile cranes 12.8.5.1 In Hong Kong, hydraulically driven mobile cranes which are operated

with hydraulic pumps and motors are sometimes used in driving other machineries in foundation work. Beside lifting work, these cranes can deliver their pressurized fluid to drive other hydraulic machineries such as vibrators and drilling machines. For the safe operation of hydraulically driven mobile cranes when driving other machineries, the following hazards should be observed:

(a) bursting of hydraulic hoses of machinery causing interruption of supply of fluid to the crane;

(b) decrease in stability of crane when attached with these machineries;

(c) increase in back pressure which may affect the safety of crane; and

(d) overheating of hydraulic fluid due to extra loading.

(b) decrease in (b) dec

(c) increase in crease

(d) overheating eatin f hydraulic fluid f hydraulic fluid due to extra loade to extra

h these machinese machine

safety of craety

ng. ng.

; and ; anane

60

113. Maintenance

113. Maintenance 13.1 Statutory requirements 13.1.1 Cranes shall be properly maintained (Regulation 4(b) of the LALGR).

Table 2 gives the legal requirements under the LALGR for the testing and examination of cranes after substantial repair.

13.2 Planned maintenance 13.2.1 In order that mobile cranes may operate safely and efficiently, it is

essential to carry out preventive maintenance work so that the risk of accidents due to breakdowns is reduced to a minimum. Manufacturer’s instruction manuals recommend that specific tasks be carried out at stated intervals and these should be followed. Any repairs or replacement of components should be in accordance with the manufacturer's recommendations or specifications.

13.2.2 In addition to any statutory regulations, a record or log should be kept

for all cranes, giving information such as diameter, length and construction details of ropes, hours worked, adjustments, insulation checks, renewal of parts, thorough examinations and repairs. The availability and source of replacement items should be checked and noted in the record.

13.3 Competence of maintenance personnel 13.3.1 All maintenance staff should be fully aware of the hazards involved in

working on cranes. Maintenance staff should have an adequate working knowledge of the machinery they are required to maintain and have access to the manufacturer's relevant literature.

accidents accid due tinstruction manruction mstated intervals ntervareplacement o ent o manufacturer's rer's

13.2.23.2.2 In addition to aon to for all cranes all crar

t ti d

components components commendation mmendatio

statutory reguatuto giving informaing

l f l f

hould be in aould be in or specifications. or specificatio

ations, a record oations, a recoon such as don such as d

ours worked adrs worked

mum. Manufactu Manufactuks be carried o be c. Any rep Ancordance wcordance w

r log should g shameter, lengeter,

t t it t

out at t ars or rs o

h the h the

e kept e kep and and

nsulation ation

d opair

with with

be gth


61

114. I

nspe

ctio

n,

EExa

min

atio

n an

d TT

estin

g

14. Inspection, Examination and Testing 14.1 There are statutory requirements governing the testing, examination

and inspection of mobile cranes (Regulations 5, 7A, 7B, 7E and 7G of the LALGR). Inspection shall be carried out by a competent person whilst test and examination shall be carried out by a competent examiner. Reference can be made to Table 2 which is a summary of the legal requirements of testing, thorough examination and inspections of mobile cranes. Testing of mobile cranes should conform to British Standard BS 7121 or equivalent standards. Reference should also be made to the Guidance Notes on Inspection, Thorough Examination and Testing of Lifting Appliances and Lifting Gear issued by The Labour Department.

14.2 Any components or jib/boom sections designed and manufactured or

altered by anyone other than the original manufacturer should be examined and certified by a competent examiner to be safe to accommodate all the loads which the jib/boom or components of the original manufacturer can sustain. Prior to the examination and certification, the competent examiner should consult the original manufacturer on the suitability of such a replacement.

14.3 Where an inspection as required under Regulation 7A of the LALGR

shows that the crane is in a safe working order, the competent person shall deliver forthwith, or within a reasonable time thereafter, to the owner the certificate of such inspection. (Regulation 22(1) of the LALGR)

14.4 Should the competent person carrying out an inspection find any defect

(such as twisted/broken wires, etc.) or abnormality in the mobile crane or in the operation of the mobile crane, or should the mobile crane be accidentally damaged, this should be reported immediately to the person responsible for the safe use of the crane. The machine should be taken out of service until the faults have been rectified and clearance is given by the person responsible for the safe use of the crane. Sufficient space on the "Checklist" for reporting the defects is recommended.

14.2 Any componen4.2 Any componaltered by any by anexamined and and accommodate date original manufa manufcertification, thtion, manufacturer o manufactur

ertified by a ertified by a the loads whie loads whurer can suser c

competent empe he suitability of suita

competent examompetent eh the jib/boom o h the jib/boomain. Prior to tPrior to aminer should aminer shou

such a replaceme such a replaceme

nd manufacture manufacturer shcturener to be ner to be

component ompoe examinat exa

consult the sult nt.

ed or d old be d bfe to fe to

of the of th and an

riginal rigin

ctureoul

saf safts o ion

or

62

114. Inspection, EE

xamination and

TTesting

14.5 Where a test or a thorough examination shows that a crane is in a safe

working order, the competent examiner shall deliver the test or examination certificate to the owner of the crane within 28 days after the test or the thorough examination (Regulation 6A(1)(a) of the LALGR).

14.6 Where a test or a thorough examination shows that a crane cannot be

used safely unless certain repairs are carried out, the competent examiner shall immediately inform the owner of the crane of that fact and shall, within 14 days after the test or the thorough examination, deliver a report to the owner of the crane and a copy of it to the Commissioner for Labour (Regulation 6A(1)(b) of the LALGR).

14.7 A competent examiner or competent person shall not deliver to an

owner a certificate or make a report which is to his knowledge false as to a material particular (Regulation 21(2) and 22(2) of the LALGR).

14.8 All test certificates and related documents shall be kept in a safe place

and be made available for inspection by any occupational safety officer. A copy of the relevant and the most recent certificate or report shall be displayed in the driving cabin or other prominent place on the equipment to which it relates or in a prominent place nearby (Regulation 18C of the LALGR).

to a material pato a mater

14.8 All test certifica4.8 All test certificaand be made avde avA copy of the re the redisplayed in the in the to which it relatech it reLALGR). LALGR).

and related dd related dlable for inspeable for inspevant and the mnt an

iving cabin or ong ca or in a promine n a

cuments shall be ents shion by any occupion by any oc

ost recent certificst recent cer her prominent plaher prominen

nt place nearby (Rnt place nearb

knowledge falsdge fa of the LALGR). e LALGR).

kept in a sa kept in a saational safety ational safeate or report or rece on the eq on t

egulation 18ulati

place place fficer. fficer.

all be all bpment pme of the of th

afe y of f sha

quip 8C o


63

115. S

ecur

ing

of

LLoad

s be

fore

lifti

ng

15. Securing of Loads before Lifting 15.1 Loads to be safely secured 15.1.1 The owner of a lifting appliance shall, before it is used, ensure that every

part of any load to be raised or lowered by the lifting appliance is:

(a) securely suspended or supported; and

(b) adequately secured so as to prevent danger arising to persons or property as a result of the slipping or displacement of any part of the load.

(Regulation 7J(1) of the LALGR) 15.1.2 The risk of the slipping or displacement of any part of the load as well as

the falling down of the load as a whole should be properly considered during the establishment of the safe system of work (see section 3 of this Code).

15.1.3 Particular attention should be paid to the provisions of proper rigging

procedures and precautions. It should also be noted that it is the responsibility of owner to ensure that the persons who direct, rig and handle the loads have received training in the principles of the operation, are able to assess weights and judge distances, heights and clearances, are capable of selecting tackle and lifting gear as well as rigging method suitable for the loads to be lifted, and are capable of directing the movement of the crane and load to ensure the safety of all personnel.

15.1.4 It should also be noted that loose materials, such as stones, bricks, tiles,

slates or other objects have to be lifted in a receptacle of adequate strength. Where a receptacle is used for raising or lowering stones, bricks, tiles, slates or other objects, the owner of the lifting appliance or lifting gear shall cause the receptacle to be enclosed or to be so constructed or designed as to prevent the accidental fall of any such objects (Regulation 7J(3) of the LALGR).

15.2 Precautions to be taken before the lifting operation

15.1.215.1.2 ThThe risk of the se risthe falling down falling doduring the esta he estathis Code). .

15.1.35.1.3 Particular atten attenprocedures and res aresponsibility o esponsibilh dl th l d h

n should be p hou precautions. caut wner to ensurner to i d t i

id to the provisio o the prov should also be should also

that the person that the person aining in the princing in the pri

of the load as w load as w properly considperlork (see sect (see

ns of proper of p noted that ted who direct, who dl f th l f th

dered eren 3 of n 3 o

gging ggin s the s th

g and g and operation ation

nsidtion

r rig it is

rig

64

115. Securing of

LLoads before lifting

15.2.1 The weights of loads to be handled should be determined or properly assessed.

15.2.2 Proper rigging methods should be established. Consideration should

be given to the effect of increasing tension on the sling with increasing sling angle to the vertical or with increasing choker angle to the vertical. It should be noted that the angle between any sling leg and the vertical should not be greater than 45 degrees unless a proper assessment with detailed calculation has been conducted. Anyhow, in no circumstances should the angle be greater than 60 degrees. Consideration should also be given to the strength of the load to resist the induced lateral force when a sling is applied across it.

15.2.3 It should be noted that long bars should be securely tied up before a

sling is being applied and a tag line or control rope should be provided to prevent the swing or rotation.

15.2.4 Suitable lifting gear, equipment and tackle should be employed.

Particular consideration should be given to the balance of the loads to be lifted. As far as reasonably practicable, designed lifting points should be provided. If lifting points are not provided, the position of the centre of gravity should be assessed. It is important that the supporting hook should be positioned directly above the centre of gravity. The type of sling and the slinging methods used should ensure that the load would not topple or slip. Attention should also be paid to the provision of an effective safety latch on the lifting hook of the crane to prevent displacement of the sling.

15.2.5 Every lifting gear, equipment or tackle to be used should comply with the

statutory requirements concerning the construction, safe working loads, marking of safe working loads, testing, examination, inspection, etc. laid down in Part III of the LALGR.

15.2.6 It should be noted that a wire rope sling should be withdrawn from

service if any of the following is revealed during an inspection/examination:

(a) the markings on the wire rope sling disappear or become illegible;

(b) there is a reduction of more than 10% in nominal rope diameter due

to prevent the sto prevent

15.2.45.2.4 Suitable lifting lifting Particular cons consbe lifted. As As should be provi e provcentre of grav of gsupporting hoosupportin

ear, equipme equipmeration should ration should r as reasonab s red. If lifting poin f lift should be hou

should be po should be

t and tackle shd tack e given to the ba e given to the

y practicable, dey practicable, s are not provide are not prov

ssessed. It is ssessed. It itioned directly tioned directly

e should be prov be pro

ould be emould be emance of the ance of the signed lifting ned d, the positio he p important tport

bove the ce bove the

oyed. oyed. ads to ads to

points poin of the of tht the t thtre of re of

mplop loa lg pon o

that ent


65

115. S

ecur

ing

of

LLoad

s be

fore

lifti

ng

to wear;

(c) the total number of visible broken wires in any length of 10 diameters exceeds 5% of the total number of wires in the rope;

(d) there are 3 or more broken wires located at a particular point on the rope;

(e) there is significant distortion of the rope due to kinking or crushing, excessive corrosion or other obvious defects; or

(f) there is an obvious damage on any fitting, ferrule or splice of the sling.

15.2.7 It should be noted that a chain sling should be withdrawn from service if

any of the following is revealed during an inspection/examination:

(a) the markings on the chain sling disappear or become illegible;

(b) there is a reduction of more than 10% in nominal diameter on any link due to inter-link wear;

(c) there is noticeable elongation on any link or any sling leg;

(d) there is an obvious crack, significant cut/nick/gouge, bent/twisted link, excessive corrosion or other obvious defects; or

(e) there is an increase of more than 10% in throat opening of any hook of the chain sling.

15.2.8 Where a sling is employed, the sling should not be allowed to damage

the load, nor should the sling itself be damaged. If the sling is to be attached to the load, the points used for attachment, e.g. lugs and eyebolts, should be suitable and adequate for the purpose of lifting the whole load.

15.2.9 Suitable packing/padding should be provided and used to prevent

damage to slings by sharp edges on loads. 15.2.10 When lifting rigid objects with slings having three or four legs, any two of

the slings, after considering the angle between the legs, must be sized in capable of supporting the total load.

15.2.11 When using multi-legged slings to lift loads in which one end is much

(b) there is a r(b) there link due to nk due t

(c) there is not is not

(d) there is an is an link, excess exces

(e) there is an ere is aof the chain of th

eable elongatioable elongatio

bvious crack, ous ce corrosion or o orro

crease of more ase ing. ing.

on any link or an any link o

ignificant cut/nick gnificant cut/ her obvious defer obvious d

han 10% in throa han 10% in th

g

nal diameter on diameter on

y sling leg; y sling leg;

/gouge, benuge cts; or or

opening of aenin

wisted wiste

hook hoo

t/tw

any

66

115. Securing of


heavier than the other, the decision to select the appropriate sling should be based on the most heavily loaded leg.

15.2.12 As far as reasonably practicable, the effective diameter of any pin, hook

or other component over which soft eyes are used should not be less than twice the rope diameter for single part legs, and four times the rope diameter for double part legs.

15.2.13 It is important to note that the weights of loads, the rigging methods

adopted as well as the safe working loads of the lifting gear, equipment and tackle should be made known to the rigging crew.

115.3 Methods of slinging, their application and limitations 15.3.1 There are many rigging methods for different kinds of loads being

handled. It should be noted that a rigging method which is suitable for handling one load might not be suitable for handling another load. In fact, each rigging method has its limitations. The methods shown in this section are intended to be typical examples and should not be regarded as exhaustive.

15.3.2 It should be noted that though wire rope slings are used for illustration,

the methods shown in this section are also applicable to the use of suitable chain sling, fibre rope or fibre sling.

15.3.3 The owner of any double or multiple sling shall ensure that it is not used

in raising or lowering or as a means of suspension if:

(a) the upper ends of the sling legs are not connected by means of a shackle, ring or link of adequate strength; or

(b) the safe working load of any sling leg is exceeded as a result of the angle between the sling legs.

(Regulation 18A of the LALGR) 15.3.4 Single-leg sling

(a) Vertical or straight lift (Fig. 8) - A vertical or straight lift is only

15.3.115.3.1 There are man There are handled. It shed. It shandling one lo one lofact, each riggi riggithis section are n are regarded as exh as ex

15.3.215.3.2 It should be not It should

might not be ght not be method has i method has i

ntended to be nded ustive. ve.

that though w that thoug

uitable for handlle for s limitations. Th limitations.

typical examples typical exam

re rope slings are e rope slings are

nds of loads of loads which is suiich ng another log another le methods se methods and should nd s

used for illu used for i

ble for le fod. In d. In wn in wn in

ot be ot b

ation, ation,

tab oad show hd no

ustra


67

115. S

ecur

ing

of

LLoad

s be

fore

lifti

ng

suitable for lifting a load that will be stable when suspended from a single lifting point.

(b) Basket hitch (Fig. 9) - A basket hitch should only be used when the sling is passed through part of the load and the load is balanced on the sling. The lifting should not commence until a shackle is connected to the sling legs. The included angle of the sling should not exceed 90 degrees.

(c) Simple Choker Hitch (Fig. 10) and Double and Choked (Fig. 11) – These two slinging methods do not grip the loads completely and should be used only when the loads are easily stabilized or cannot slip out of the sling.

(d) Choker hitch double wrapped (Fig. 12) - The general limitations for this sling method is similar with simple choker hitch, except that with the double wrapped choker hitch the load is gripped more fully, and hence is secured more effectively.

Note : The simple choker hitch or choker hitch double wrapped method should not be

used for handling composite loads such as loose bundles of tubes, or bars or

wooden battens unless the friction grips between the parts is sufficient to prevent

them slipping from the sling. As far as possible, such composite loads should

first be tied up securely at their ends by steel wires or similar means of adequate

strength.

and hence and h

Note : The simple c mple c

used for han or han

wooden batteen batt

them slipping m slipp

first be tied ufirst be

ker hitch or chokeer hitch or choke

g composite load ompo

unless the friction ess t

om the sling. the s As

ecurely at their enurely at

hitch double wrapp hitch double w

s such as loose bun such as loose

grips between the paps between th

far as possible, such far as possible,

s by steel wires or ss by steel wires or s

s gripped more d more

d method shoud method sho

dles of tubes, o of tu

rts is sufficient t s suff

composite loampos

milar means of ar mean

not be not be

bars or bars

prevent reve

should shou

equate equate

uld uld

or b

to p

ds s

ade

68

115. Securing of


Fig. 8 Vertical or straigght lift FFig.. 99 BBasket hitch

90o max.

Fig.. 110 Simple chokerr hhitch Fig.. 111 Doubled and choked

FFig. 8 Verttiiccaall oorr sstra itch


69

115. S

ecur

ing

of

LLoad

s be

fore

lifti

ng

Fig.12 Choker hitch doublle wrapped

d

Fig. 13 Two single-leg slings used with direct attachment

15.3.5 Multi-leg sling 15.3.5.1 A multi-leg sling may have two, three, four or more legs (Fig. 13 to 19).

It provides a more stable lifting arrangement than a single-leg sling. 15.3.5.2 Generally multi-leg sling methods are:

(a) two-leg slings used with direct attachment (Fig. 13);

(b) two-leg slings used in choker hitch (Fig. 14);

(c) two-leg slings used in basket hitch (Fig. 15);

(d) two-leg slings used in double wrap choker hitch (Fig. 16);

(e) two-leg slings used in double wrap basket hitch (Fig. 17);

(f) three-leg slings used with direct attachment (Fig. 18); and

(g) four-leg slings used with direct attachment (Fig.19).

Fig. h dou

15.3.5 Multi-leg sling 5.3.5 Multi-leg sling

g. 13 Two sinrect

eg slings usment

withed

70

115. Securing of


Fig. 114 TTwo single-lleg slings used in chokerr hhitch

Fig.. 115 TTwo single-lleg slings used in basket hitch

90o max 90o max

15.3.5.3 When using multi-leg slings, care should be taken to ensure that:

(a) the slings are of the same length;

(b) where the slings have different safe working load ratings then the load that can be lifted is related to the least safe working load; and

(c) the attachment points of a two-leg sling to the load are far enough apart to give stability without exceeding 90 degrees (Fig. 13, 14 & 16). In the case of a two-leg sling used in basket hitch or a four-leg sling, the angle between any two diagonally opposite legs should not exceed 90 degrees (Fig. 15, 17 & 19). For a three-leg sling, any one leg should make an angle of not greater than 45 degrees with the vertical.

Note: The two-leg slings used in choker hitch, basket hitch, double wrap choker hitch

or double wrap basket hitch should not be used for handling composite loads

such as loose bundles or tubes, bars of wooden battens unless the friction grip

between the parts is sufficient to prevent them slipping from the sling. As far as

possible, such composite loads should first be tied up securely at their ends by

steel wires or similar means of adequate strength.

such as loossuch as

between the ween the

possible, sucle, suc

steel wires or res or

omposite loads s omposite loads s

milar means of adr means of ad

ould first be tied up d first be tie

quate strength. quate strength.

andling composite composite

s unless the frictioess the frict

rom the sling. the

securely at thei securely at the

on grip gr

far as far a

nds by nds by

rictio

As

ir enir en


71

115. S

ecur

ing

of

LLoad

s be

fore

lifti

ng

Fig.. 18 TThree-lleg sling

45o max

Fig.. 119 FFour--leg sling

90o max

Fig.. 117 TTwo single-leg slings in ddouble wrap basket hitch

Fig. 16 Two single-leg sllings in double wrap chooker hitch

90o max 90o max

Fig 1 T o singlewrap c

g slp ba h

72

115. Securing of


115.4 Precautions to be taken in fitting the slings 15.4.1 When fitting the sling to a load, steps should be taken to ensure that:

(a) sling legs are free of kinks or any tendency to kink;

(b) only the eye termination with thimble is placed on the crane hook;

(c) the terminations are properly seated without overcrowding;

(d) the load is effectively secured by the sling;

(e) the relevant leg angle does not exceed that for which the sling is rated and marked;

(f) the sling is not bent around any corners that might damage or reduce the effective strength of the sling. Where necessary suitable packing pieces should be used;

(g) when using choke hitch:

(i) the angle of choke is allowed to form itself naturally and is not forced;

(ii) a thimble or stirrup is used where practicable at the eye to reduce damage to the rope and thereby prolong the life of both the eye and the main part of the rope; and

(h) a tag line or control rope is available for assisting in the control of the swing or rotation of the load.

(g) when using (g) when u

(i) the an the anforced orced

(ii) a thim thimreduce reducthe ey the

(h) a tag line o(h) a

e or stirrup is r stir amage to the rage nd the main pa the

control rope is control rop

used where prac sed where p pe and thereby ppe and thereb

t of the rope; t of the rope; and

available for assis vailable for ass

f naturally an atura

cable at the ble a olong the life ng t

ting in the coting in the

is not is no

ye to ye t f both f bot

ontrol of rol of

nd i

e e e of

ont

TTable 1 - Recommended hand signals

1. EMERGENCY STOP 2. STOP 3. TRAVEL 4. TRAVEL TO ME 5. TRAVEL FROM ME

6. INDICATING DISTANCE TO TRAVEL

7. TURN TO DIRECTION INDICATED

8. TURN TO DIRECTION INDICATED

9. SWING IN DIRECTION INDICATED

10. SWING IN DIRECTION INDICATED

11. RAISE BOOM 12. RAISE BOOM LOWLY 13. LOWER BOOM 14. LOWER BOOM SLOWLY 15. RAISE THE BOOM AND LOWER THE LOAD

16. LOWER THE BOOM AND RRAISE THE LOAD

17. EXTEND BOOM 18. RETRACT BOOM 19. USE MAIN HOIST 20. USE AUXILLIARY HOIST

21. LOWER HOIST 22. LOWER HOIST SLOWLY 23. RAISE HOIST 24. RAISE HOIST SLOWLY 25. STOP EVERYTHING

66.. IINNDDIICCAATTIINNGG DDIISSTTAANNCCEETTOO TRAVEL

77. TURN TO DIRIINNDICATE

1111.. RRAAISE BOOM 1122.. RRAAISE BOOM WLY 113. LOWER BO MM 1144. LOWERR BBOOOOMM SLOW

10. SWWIINNGG IN DIRREECCTTIIOOIINNDICATED

LY 155.. RRAAIISSE THE BOOLLOOWWEERR TTHHE LO

NNDDOM AOAD

Table 2 - Frequency of test, thorough examination and inspection of mobile cranes under the LALGR Regulation

NNo. Testing && Thorough

Examination Testing Thorough EExamination Inspection Approved

Form No.

5(3)

7B

during the preceding 4 years before use (includes the test of the automatic safe load indicator)

3

5(5)

7B

before use, after undergoing substantial repair, re-erection, failure, overturning or collapse (includes the test of the automatic safe load indicator)

3

5(1)

at least once in the preceding 12 months before use

5

7A

7B

within the preceding 7 days before use (includes the inspection of the automatic safe load indicator)

1

7E

after erection, removal to a new location, or adjustment of any component member ( being a removal or adjustment which involves changes in the arrangements for anchoring or ballasting), the crane shall be tested before use.

all the devices used for the anchoring or ballasting of the crane shall be thoroughly examined before the crane is erected.

2

7G

after exposure to weather conditions likely to have affected the stability of the crane, the crane shall be tested before use.

2

Note 1: The requirements for testing/examination of lifting gear are not included in the above table.

Note 2: Reference should be made to the full text of the LALGR.

Note 3: Repair includes renewal, alteration or addition and examples of substantial repair include replacement of wire rope, replacement of brake, alteration of boom length or jib length, changing of hook block, and any repairs on steel structure which may affect the integrity of the crane.

5(1)5(1

7A7A

7B7B

after erection, refter ereto a new locatioto a new l

oval oval , or or

all the devices all the devices used for theused for the

within the within the preceding 7 ceding days before use s befo(includes the udes inspection of the ectio automatic safe matic load indicator) indic

55

11

e e 7 e e e e

RReferences 1. BS 7121-1:2016

:

Code of Practice for Safe Use of Cranes – Part 1: General

2. BS 7121-2-1:2012

:

Code of Practice for the Safe Use of Cranes Part 2-1: Inspection, maintenance and thorough examination – general

3. BS 7121-2-3:2012

:

Code of Practice for the Safe Use of Cranes Part 2-3: Inspection, maintenance and thorough examination – Mobile cranes

4. BS 7121-2-4:2013

:

Code of Practice for the Safe Use of Cranes Part 2-4: Inspection, maintenance and thorough examination – Loader cranes

5. BS 7121-3: 2017

: Code of Practice for Safe Use of Cranes – Part 3: Mobile cranes

6. BS 7262:1990

:

Specification for Automatic Safe Load Indicators

7. BS EN 818-6:2000 + A1:2008

:

Short Link Chain for Lifting Purposes – Safety – Part 6: Chain Slings – Specification for information for use and maintenance to be provided by the manufacturer

8. BS EN 12077-2:1998 + A1:2008

:

Crane safety - Requirements for health and safety - Part 2: Limiting and indicating devices

9. BS EN13414-2:2003 + A2:2008

: Steel Wire Rope Slings – Safety – Part 2: Specifications for information for use and maintenance to be provided by the manufacturer

4.4. BS 7121BS 7121 2 4:2013

5.. BS 7121-3: 17

6.6. BS 7262:1990BS 7262:1990 ::

:: Code of PCode of 3: Mobile 3:

SpecificatSpI di tI di

actice for Safactice for Safe Ue raness

onon for Automfor Autom

fe Use of Crane of Cranmaintenance atenaer cranes cran

e of Cranes f Cr

tic Safe S

and d

Part Part

oad oad

a

– P

Lo

10. BS EN 12999:2011+A2:2018

: Cranes – Loader cranes

11. ASME B30.5: 2018

: Mobile and Locomotive Cranes

12. ASME B30.22:2016

: Articulating Boom Cranes

13. ISO 12480-1:1997 : Cranes – Safe use – Part 1 : General

14. ISO 15442:2012+A1:2015

: Cranes – Safety requirements for loader cranes

15. Guidance Notes on Inspection, Thorough Examination and Testing of Lifting Appliances and Lifting Gear issued by the Labour Department, Hong Kong SAR

16. Crane Hazards and their Prevention - David V. MacCollum, ASSE, USA

17. Cranes and Derricks - Howard I. Shapiro, Jay P. Shapiro, Lawrence K. Shapiro, McGraw Hill, Inc., USA

18. Rigging manual - Construction Safety Association of Ontario, Canada

19. Lifting Tackle Manual - Donald E. Dickie, Construction Safety Association of Ontario, Canada

20. Mobile Crane Manual - Donald E. Dickie, Construction Safety Association of Ontario, Canada

21. Crane Handbook - Donald E. Dickie, Construction Safety Association of Ontario, Canada

22. A Safety Handbook for Slingers and Crane Operators, RoSPA, UK

23. Code of Practice on Working near Electricity Supply Lines issued by the Electrical and Mechanical Services Department, Hong Kong SAR

16.6. Crane Hazards and ards an

17.7. Cranes and DerrickserricksShapiro, McGraw Haw H

18.8. Rigging manual anual - Co

Howard I. ShaHoward I. Sha Inc., USA., US

struction Safety ctio

iro, Jay P. Shapirro, Jay P. Sh

Association of On Association of

um, ASSE, U ASS

o, Lawrence o, Lawrence

tario, Canadao, C

A USA

K. K

a

24. Code of Practice on Wind Effects in Hong Kong – 2004, Buildings Department, Hong Kong SAR

Ennquiries

If you wish to enquire about this Code of Practice or require advice on occupational safety and health matters, please contact the Occupational Safety and Health Branch of the Labour Department through:

Telephone 2559 2297 (auto-recording service available after office hours

Fax 2915 1410

E-mail : [email protected]

Information on the services offered by the Labour Department and on major labour legislation is also available on our website at http://www.labour.gov.hk.

For details on the services offered by the Occupational Safety and Health Council, please call 2739 9000.

Complaints

If you have any complaints about unsafe workplaces and work practice, please call the Labour Department's occupational safety and health complaint hotline at 2542 2172. All complaints will be treated in the strictest confidence.

legislation legislation isis also also availableav

For details on or d the services serviceplease call 2739leas 9000.00.

Co nts

and on major la n major lar.gov.hkv.hk.

and Health d H ouncil, unc Co

occupational safety and health branch Ø Ç Ì Ú · 2019. 1. 7. · code of practice for safe use...

Documents