accidents that can be prevented through design and examples of … · 2015-10-26 · a great...

A Great Workforce A Great Workplace

Accidents that can be prevented through

design and examples of DfS

DFS Forum

Tong Tee Hui , Senior Assistant Director (OSH Inspectorate) OSHD, MOM

21 Oct 2015


1

A Great Workforce A Great Workplace WSH (Design for Safety)

Regulations

Workplace Safety and Health (Design for

Safety) Regulations 2015 was gazetted on 10 July 2015. The Regulation comes into operation on 1 Aug 2016.

The Regulations apply to a project that —

(i) is undertaken by a developer in the course

of the developer’s business;

(ii) involves or is intended to involve any

construction work of a contract sum of $10

million or more; AND

(iii) involves development under section 3(1) of

the Planning Act (Cap. 232);

OR

a project to modify a permanent structure, in

respect of which a design for safety register has

been kept under regulation 7, that involves

development under section 3(1) of the Planning

Act.

These Regulations do not apply to a project in respect of which the developer has appointed a designer before 1 August 2016.

A Great Workforce A Great Workplace Accidents in Construction

22 26 33

27 23 16

5.5 5.9

7

5.5

0

20

40

60

80

100

1

2

3

4

5

6

7

8

2011 2012 2013 2014 2015 2016 2017 2018

Workplace Fatality & Fatality Rate - Construction

2015

Target FR

3.4 2018

Target FR

1.8

*Prelim stats for 2015 till date (as of 18/10)

For the whole of 2014, there were 27 fatalities in construction.

Minor injuries increased by about 10% each year – 9,505 (2011) to 10,469 (2012) to 11,467 (2013) and 12,863 (2014).

Overall major injury rate rose from 364 (2011) to 384 (2012) to 403 (2013) and 672 (2014).

Construction accounted for highest 27 out of 60 fatalities in 2014 and remains the industry with the highest fatalities in 2015 till date.

Efforts need to be placed at all fronts,

and include

(i) Improvements to upstream

processes where efforts would

yield the highest returns in

improvements to safety and

health

(ii) Getting all stakeholders to be

aware of their responsibilities

The top 3 type of accidents that resulted in fatality in 2015 are • Falls from Height, • Struck by Moving Objects and • Collapse/Failure of Structure & Equipment.

The 3 type of accidents accounted for 44% of fatal cases in 2014 and 58% of fatal cases up to Sep 2015.

Prosecution relating to CDM 2015 - Client

A Grantham building contractor and South Kesteven District

Council have been fined more than £20,000 after a spread of

asbestos during a flat renovation.

In March 2010, workers from Belton Developments disturbed asbestos

at the council property in Kinoulton Court while converting a bathroom

into a wet room. The workers removed asbestos insulation board from

around the bath and carried it through the flat and communal areas of

the housing complex in an open wheelbarrow before loading it into an

open-topped van.

The process was spotted by an on-site asbestos surveyor. He stopped

the work and called in a licensed asbestos contractor to decontaminate

the area and carry out air clearance tests.

The Health and Safety Executive (HSE) told Grantham Magistrates'

Court the council had failed to provide adequate information on

asbestos in the property to Belton Developments before work began.

The council also failed to ensure that Belton Developments was

competent to carry out work with asbestos.

South Kesteven District Council pleaded guilty and was fined £16,600

and ordered to pay costs of £3,486. Belton Developments was fined a

total of £3,003 and ordered to pay costs of £900.

• Developers have to ensure that the person engaged as a designer/ contractor is competent to perform his duties • And ensure that all relevant information is given to the designer and contractor appointed to allow him to perform his duty

Design Review and the Guide Process

GUIDE 1: Concept Design Review GUIDE 2: Detailed Design, Maintenance and Repair Review GUIDE 3: Pre-Construction Design Review

The GUIDE Process – GUIDE 1

A Great Workforce A Great Workplace Case example

Building Collapsed In Shanghai (06/27/2009) (Daqi) At around 5:30am on June 27, an unoccupied building still under construction at Lianhuanan Road in the Minhang district of Shanghai city toppled over. One worker was killed. According to information, a 70 meter section of the flood prevention wall in nearby Dianpu River and that may have something to do with this building collapse. (China Daily)


Pre-stressed high-strength concrete (PHC) hollow foundation piles that were uprooted

Case example

• Issues with integrity of the permanent building structure? • Prior to excavation works, information on the foundation of adjacent buildings obtained and communicated?

• The design of the excavation and retaining structure catered for surcharge from stockpiled excavated material ? • Prior to commencement of such works, a design review process, if well implemented may have prevented similar incidents from happening.

A Great Workforce A Great Workplace The GUIDE Process – GUIDE 2


3 Aug 2015 - Two cranes hoisting a massive section of bridge collapsed flattening a row of houses injuring at least 20 people. Dramatic videos of the accident in western Holland, showed the section of roadway swinging out of control and falling onto the homes, to the screams of onlookers.


• Were alternative methods of construction assessed during the design phase? • Considerations for lifting operations assessed? • Foundation for which the cranes were deployed (i.e. on pontoons) adequate? • Cordoning off the worksite / evacuation of buildings affected during the lifting operation required? • Alternative methods to replace tandem lifting ?

A Great Workforce A Great Workplace The GUIDE Process – GUIDE 3


On 29 Dec 2014, a reinforcement cage for a thick concrete slab collapsed at a worksite for the construction of the stadium’s foundation at Beijing. The accident happened during fixing of reinforcement bars for a 1.5m thick raft structure. 10 workers were killed and 4 were injured.


• Temporary structure (i.e. bar chair) designed by competent PE?

• Adequate safety factor accorded for the temporary structure? • QP had checked the design and endorsed it to be safe for construction?

Other areas of consideration - Maintenance

Other areas of consideration - Prefabrication

• Drive towards use of PPVC and PBUs • Reduces manpower required at the worksite

• Conventional issues of lifting points and working at height during rigging / unrigging of components, and for alignment of components need to be addressed.

Other areas of consideration – Falling from Height

Travel restraint system

Fall arrest system – using full-body harness

Construction accident investigation reports for fatal accidents that occurred in the year of 2012 in Singapore were used in the analysis. A total of 25 cases in the construction industry were assessed. These reports consist of detailed information and accounts of the accident, hazards at the worksites and conditions that may have led to the accident. The information was assessed to determine if there is any association between the accident and design for safety elements.

Study on accident cases in 2012

a) Is the accident foreseeable during the design stage? b) Can the risk or hazard identified be addressed by design during the design stage? c) Can the risk or hazard identified be addressed by design during the construction stage? d) If the risk or hazard identified cannot be addressed by design, could other mitigating measures have been implemented, that would have prevented the occurrence of the accident? e) Are there any situations of which no means or measures taken would have mitigated, resolved or minimized the risk or hazard identified?

A forklift operator drove a forklift

to transfer a steel truss beam

within a construction worksite.

The Deceased was welding

another beam and he happened

to be in the path of the forklift.

The forklift operator had to raise

the forks of the forklift in order to

clear over a concrete stump. In

the process, the steel beam

struck the Deceased.

The operator, in a moment of

panic, lowered the forks and the

beam crushed the Deceased.


Photos show some erected truss beams


Steel pipes that the deceased was grinding and

concrete stump

• Design plan should address method of safe lifting of the long and

non-symmetrical steel structures.

• Lifting hooks installed on steel sections would allow the steel sections

to be lifted using crane

• If a forklift has to be used, pallets could be designed to allow for safe

lifting of the non-symmetrical sections.


The Deceased and two co-

workers were tasked to tie

netting on the barricades and

clear the materials within an

excavated trench. At about

1030hrs, the Deceased

descended into the trench in

order to retrieve a “changkol”

(hoe). When he was inside the

trench, the sides of the trench

suddenly caved in around him,

and the Deceased was crushed

by the earth and part of the

timber shoring. The Deceased

was subsequently rescued and

conveyed to the hospital. He

succumbed to his injuries at

about 1715hrs on the same day.


• There was no information

available on how the shoring was

to be constructed

• No assessment was done as to

the adequacy of the shoring

system

• Different shoring methods were

seen at different trenches

• The risk assessment and safe

work procedures did not address

the works for the construction of

the shoring system within the

excavations and the PTW system

for excavation works was not

properly implemented

• Construction accident investigation reports for fatal accidents that occurred in

the year of 2012 in Singapore were used in the analysis.

• A total of 25 cases in the construction industry were assessed.

Accidents that may have been prevented if design for safety elements were incorporated during design and construction stages (a)

Accidents that could have been mitigated if proper measures were implemented during construction (b)

Accidents that cannot be assessed due to insufficient information or could not be prevented even if proper design or measures were taken

44% 44% 12%

Design stage

Construction stage

24% 20%


A Great Workforce A Great Workplace Conclusion

Efforts need to be placed at all fronts, and include:

(i) Improvements to upstream processes where efforts would yield the highest

returns in improvements to safety and health

(ii) Getting all stakeholders to be aware of their responsibilities

accidents that can be prevented through design and examples of … · 2015-10-26 · a great...

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