project report on ship rudder
TRANSCRIPT
STUDY OF RUDDER AND RUDDERSTOCK WITH
STEERING GEAR MECHANISM
A project report submitted in partial fulfillment of the requirement
for the award of the degree of
BACHELOR OF ENGINEERING IN MECHANICAL
ENGINEERING
By
M. Sekhar (121FA08044)
K. Brahmaiah(121FA08029)
N. Teja (121FA08048)
V. Ashok(121FA08137)
Under the esteemed guidance of
External Guide: Internal Guide:
Sri Prakash Himansu sekhar dash
Engineer, Assistant Professor,
Dept. of Engineering Dept of Mechanical Engg.,
Hindustan Shipyard Ltd., Vignan’s university,
Visakhapatnam. Guntur.
PREFACE
This project report covers the “Study of Rudder and Rudderstock
with steering gear mechanism.” The entertaining colorful drawings
coupled with, easy to understand explanation makes this report
worthwhile in every respect.
We have taken special care to cover all topics in the most
satisfactory way providing latest information regarding them,
supplemented by neat diagrams.
This very report is purely going to stand you in good stead
when you are faced with the host of difficulties steering system
and related topics.
We are highly thankful to Sir Prakash who has
cooperated with us to present this report successfully.
M. Sekhar (121FA08044)
K. Brahmaiah(121FA08029)
N. Teja (121FA08048)
V. Ashok(121FA08137)
.
CERTIFICATE
This is to certify that the following students has undertaken and
successfully completed this project work entitle “ Study of Rudder
and Rudder Stock with Steering gear mechanism” which is a
bonfire record of work in practical fulfillment for the award of the
degree of Bachelor of Technology being submitted to Vignan’s
University, Guntur under our guidance.
The results embedded in this report have not been submitted to any
other university or institute for the ward of any degree or diploma.
M.Sekhar(121FA08044)
K. Brahmaiah(121FA08029)
N. Teja (121FA08048)
V. Ashok(121FA08137)
Under the esteemed guidance of
External Guide: Internal Guide:
Sri Prakash Himansu sekhar dash
Engineer, Assistant Professor,
Dept. of Engineering Dept of Mechanical Engg.,
Hindustan Shipyard Ltd., Vignan’s university,
Visakhapatnam. Guntur.
DECLARTION
I here by declare that this project work titled “STUDY OF
RUDDER AND RUDDERSTOCK WITH STEERING GEAR
MECHANISM.” This is a report of original project work done by
us under the guidance of Mr. Himansu sekhar dash, as an internal
guide and Sri Prakash as an external guide, and this project work
has not formed the basis for the award of degree/diploma/associate
ship/fellowship or similar titles to any other candidates of any
university.
Date:
M. Sekhar (121FA08044)
K. Brahmaiah(121FA08029)
N. Teja (121FA08048)
V. Ashok(121FA08137)
Under the esteemed guidance of
External Guide: Internal Guide:
Sri Prakash Himansu sekhar dash
Engineer, Assistant Professor,
Dept. of Engineering Dept of Mechanical Engg.,
Hindustan Shipyard Ltd., Vignan’s university,
Visakhapatnam. Guntur.
ACKNOLEDGEMENTS
We extend our sincere thanks to Sri Sanyasi Rao, Manager training
for resource the extended.
We also thank Mr. Anil, Supervisor and our training department
for the pains he took in scheduling our program.
We are deeply indebted to our beloved external guide Sri
Prakash, Engineer, Department of Engineering and internal guide
Sri Himasu sekhar dash, Mechanical Engg, Vignan’s university for
their in valuable guidance and keen interest in bringing out this
project work. We would not have been able to accomplish this
project so successfully without their help and guidance. It has been
a great pleasure to work on this project.
We are very much thankful to our guides for their
valuable suggestions and having given us all encouragement for
completing this project. We are also thankful to all teaching and
technical staff members of the Department of Mechanical
Engineering without their assistance this work could not have been
undertaken at all.
ABSTRACT
Present project deals with the study of “Study of Rudder and
Rudderstock with steering gear mechanism”.
Ship owners and all those concerned with the operations of
ship and safety of life at sea have progressively called for
improvement in methods of steering ships and steering gear
equipments.
The basic principle involved in steering gear system is
diverting the flow of fluid by the help of rudder. Steering system is
operated by the horizontal component of thrust force.
So in order to turn the ship towards either port or
starboard side, the steering system is compulsory.
While doing the project, we design the components
of steering system and studied the operations or steering gear
system.
GENERAL DESCRIPTION
STEERING GEAR:
The FRYDENBO steering gear on this vessel is composed of
one hydraulic rotary vane actuator mounted directly on the
rudderstock, served by two pump units delivering the necessary
oil pressure for operating the rudder.
The two pump units may be operated together or separately.
Each pump unit will provide oil with sufficient pressure to
develop the specified rudder torque.
When cruising at sea, only one pump unit is normally in
operation while the other is acting as a stand-by unit. During
curve of the vessel, when the shortest possible steering time is
required, it is possible to run both pump units simultaneously
where by the rudder rate will be doubled.
The pump units are equipped with solenoid values, which are
normally operated by means of signals from the bridge steering
controls.
The pump is submerged in the oil tank. The tank is divided into
two chambers, one for each pump unit, with one low level
alarm-switching each of the pump unit chambers.
From top of the steering gear leakage oil will run through pipe
to the oil tank
THE ACTUATOR: The actuator consists of these main components:
1. Housing
2. Cover
3. Rotor
4. Stoppers
5. Vanes
6. Safety relief valve
LOCK VALVE:
The automatic lock valve mounted on the actuator consists of
housing, where both pipes from the pump unit are connected.
Between inlet and outlet there is a pilot-piston which operates
the two spring-loaded valves.
SAFETY VALUE:
There is one safety valve-block on the actuator consisting of:
1. Pilot relief valve
2. Pilot piston
3. Check valve
4. Spring loaded main valve
5. Adjusting screw for relief pressure.
NORMAL RUNNING CONDITION:
CASE 1: The working pressure P1, opens the check valve, 3,
and will keep the safety valve in closed position.
SAFETY VALVE OPENS:
CASE 2: If the pressure increases to maximum, P2, Which is
the opening pressure for the pilot relief valve, 1, the spring
loaded main valve, 4 will be pushed over and the maximum
pressure will be relieved over to the suction side.
THE PUMP UNIT
The pump unit consists of following components mounted on a
common bed plate:
1 Oil tank with two chambers.
2 Flexible coupling between motor and pump.
3 Solenoid operated control valve for connection to
steering controls, with emergency push-button steering
controls
4 Electric motor.
5 Pressure gauge.
6 Safety relief valve.
7 Filter.
FUCTIONING OF THE PUMP/CONTROL UNIT
BEGINNING OF STEERING (MODULATED FLOW):
Steering is carried out by operating the solenoid valve(1). Fig.2 on
the diagram shows the beginning of the steering process when the
right solenoid is operated. The control valve (3) will be pushed
over to the right side by the oil pressure in the left chamber.
The control valve (3) is now at the beginning of its stroke. Some of
the oil flows through the throttling slots to the actuator, and
overflow is by-passed at the by-pass valve (4) back to the suction
side of the pump. The smaller oil volume being directed gradually
to the actuator will give a soft start
STEERING:
After approximately one second, the control valve (3) is moved
over to it’s end position, see fig.3,
The oil-flow from the pump has now free passage from channel
(1) into pipe (B) leading to the actuator. The return oil from the
actuator flows through pipe (A) and has free passage to channel
(2) and back to the suction side of the pump.
FUNCTIONING OF PUMP/CONTROL UNIT:
FIG 4
RELIEF VALVE (Item 2):
When the oil pressure, C, exceeds the present valve spring load 5,
will open (fig 4). The pressure oil will flow to channel 2 and the
pressure behind the by-pass valve 7 will drop. Now the by-pass
valve will open, allowing the oil (D) to flow to the return channel
(2).
SETTING THE RELIEF VALVE (Item 2):
To increase the pressure turn and adjust the screw in clockwise,
Safety valve opening press has been set during the assembly by the
suppliers and possible adjustment should only be carried out by a
competent person.
EMERGENCY OPERATIONS:
During the emergency operation the solenoid valves (1) can be
manually operated by means of manual controls on the solenoid
valves.
Note: “local/remote switch S3, on the starter cabinets, has to be in
local position during emergency operation, use handle attached to
the pump unit to operate the manual controls.
We push buttons on solenoid value to operate the manual controls.
FUNCTIONING OF THE ACTUATOR: (See assembly drawing of actuator)
The actuator consists of 3 main components: A cylindrical housing
with stoppers, a rotor and a bolted-on cover.
The rotor, turning in bearings at top and bottom is equipped with
vanes upon which the oil pressure is acting and there by
developing the turning torque. The turning movement is limited by
stoppers to the housing.
The stoppers also act as mechanical rudder stops is hard-over
position.
The axial bearing thrusting of the actuator is of sufficient capacity
to carry the full weight of rudder, rudderstock and rotor,
eliminating the need for a separate rudder carrier bearing.
In addition to the stoppers, the actuator is equipped with electrical
limit switches stopping the turning movement at the predetermined
angle.
The steering system consists of synthetic oil resistant material
resting in seal grooves, preventing effectively internal leakages and
gland seals preventing external leakage. The bearings of the
actuator are greased by means of the system oil.
AUTOMATIC LOCK VALUE:
The actuator is equipped with automatic lock valves. If there
should be loss of oil pressure due to possible external failures, the
lock value will close immediately and keep actuator intact for
operation by means of the stand by pump.
SAFETY VALUE:
The actuator is equipped with a safety valve, limiting the process
to the specified value.
INSTALLATION:
RUDDER ACTUATOR:
Sufficient space for inspection and service of the gland scale must
be provided. There should be sufficient space between top of the
rudder actuator and the deck above to permit the cover the rotor to
be lifted. If this cannot be arranged, a hatchway in deck may be
provided. Tackle bracket should be arranged.
Do not open the rudder actuator during installation. Forward
position is marked on the actuator flange. 0-position of rotor is
marked on top of the actuator. See arrangement drawing.
Make sure that the rudderstock and actuator are aligned.
For fastening of the rudderstock to the rudder actuator,See
“Procedure for hydraulic mounting dismounting of the rudder
actuator on the rudderstock”.
PROCEDURE FOR HYDRAULIC
MOUNTING/DISMOUNTING OF THE RUDDER
ACTUATOR ON THE RUDDERSTOCK
PULL UP LENGTH: 10,12 MM (min)
PULL UP LENGTH: 10,73 MM (max)
PISTON AREA: 940 CM2
PISTON STROKE: 18 MM
RUDDERSTOCK DIA: 427 MM
CALCULATION NO: 3130
FILLING OF OIL AND VENTING PROCEDURE:
Before starting to fill oil, open all vent plugs on the actuator.
Fill oil into the oil tank of the power pack.
ACTUATOR:
Start the pump units (check the correct rotation). Operate the
solenoid valves manually for a few seconds, to move the rudder.
Repeat this procedure until the actuator is filled up with oil, and
vent the system.
Do the same operation on the second pump unit.
VENTING PROCEDURE:
Start the pump units.
Operate the solenoid valves manually to move the rudder. Stop the
pumps and vent the system.
Start again and move the rudder hard-over to hard-over.
The system should now operate smoothly without noise. If still
noisy, repeat the venting.
IF A HYDRAULIC SYSTEM IS TO BE RELIABLE AND
FUNCTION SATISFACTORILY, ALL AIR MUST BE
REMOVED FROM THE SYSTEM.
PROCEDURE FOR START-UP AND SEA TRAIL:
START-UP:
Fill oil into the actuator and the pump unit according to instruction,
and bleed the system.
- Control that the electric motor is rotating in the correct
- Run the rudder hand over to both sides. Control that the rudder
moves without any obstructions and that maximum rudder angle
is obtained. Adjust electrical end stoppers, if necessary.
- Half the total rudder angle is the correct center position. Adjust
both the mechanical and the electrical rudder indicators
according to this 0-point. Control that the steering handles and
the rudder indicators both show correct direction.
- Check that the relief valve opens at maximum specified
pressure, by pushing the emergency push-buttons on the
solenoid valve until the rudder is in hand-over position. To
obtain correct pressure, adjust relief valve (see instructions).
- Test the start and stop switches.
- Test the alarm panels
SEA TRIAL:
Check that these items are within the limits of the specification for
the supplied steering gear, using both one and two pumps:
- Steering time 35-0-30 deg.
- Maximum working pressure.
PERIODICAL MAINTENANCE:
The actuator should regularly be visually inspected for external
leakage, paintwork, damages etc.
A clean actuator will facilitate the inspection work.
A continuous undisturbed functioning of the steering gear is
dependent on two simple points:
Use the specified hydraulic oil
Keep the hydraulic system clean
The hydraulic oil and the interior of the installation should be kept
absolutely free from any impurities and air.
If these points are adhered to the preventive maintenance will be
limited to following:
YEARLY:
A. Oil filters in the pump unit to be changed.
B. Stuffing glands on the actuator to be checked.
C. Change hydraulic oil.
D. Oil filter.
After the first 200 hours running, the oil filter should be
opened for inspection and changed if necessary. If you
find impurities, change of the filter must be prepared at
short intervals until it says clean. This indicates that the
hydraulic system is clean and the filter should now be left
for the yearly change.
EVERY SECOND YEAR:
A. The hydraulic pump.
The hydraulic pump will normally last more than 10 years.
A worn pump should be replaced or repaired. A worn
pump means reduced pumping capacity indicated by
slower steering speed.
B. The rotor seals and the gland seals are practically the only
wearing parts.
Unintended movement (creeping) of the rudder at sea
indicates wear on the rotor seals. Based on experience, the
normal life time of the rotor seals is 5 to 10 years.
CHANGE THE FILTER OF THE PUMP UNIT:
Open the cover of the filter, lift out the filter cartridge
Loosen the Allen screw at the bottom of the filter cartridge, and
remove the rod, magnet (N/A on all filters), top and spring.
Mount the rod, magnet, top and spring on the new filter cartridge,
and insert it into the filter housing.
Reassemble the cover and tighten up the nuts.
PROCEDURE FOR HYDRAULIC
MOUTING/DISMOUNTING OF THE RUDDER
ACTUATOR ON THE RUDDERSTOCK.
The taper area of the rudderstock should be adapted to the rudder
actuator. Use blue color, until sufficient contact between the rudder
stock and the rotor has been obtained (according to classification
requirements)
NECESSARY EQUIPMENT:
1. Dial gauge min 1000bar
2 .High pressure oil pumps with pressure gauges,
OIL SPECIFICATION:
Hydraulic oil: 100mm2/s at 40
0C.
NOTE: No anti-friction additives allowed in oil.
MOUNTING:
1. Clean and lubricate the taper area of the rudderstock and
the rotor using hydraulic oil.
2. Put the rudder actuator on the rudderstock with its full
weight on the taper area.
3. Mount the hydraulic nut and tighten by hand.
4. Mount pump 1 for oil pressure to the nut, and pump 2
for oil pressure to the taper.
5. To find a correct starting position for the pull up length,
start to pump oil into the nut with pump until the
pressure starts to increase (max. 10 bar). Relieve the
pressure and tighten the nut until contact between nut
and actuator is obtained. This is to avoid that the o-ring
on piston in the nut should break if too long stroke. (For
permissible length of stroke, see arrangement drawing.)
This is the starting position.
6. Mount the dial gauge and adjust to zero and then pump
oil (pump 2) to the taper fitting until the oil leaks out at
the lower part of the taper. Increase slowly the pressure
from both pumps 1 and 2 until the rudderstock is pulled
up the length “L”, specified in the table.
NOTE: When pulling up, keep pressure as high as possible on
pump 2(Until the oil leaks out at the lower part of the taper).
Wait about 30 minutes and then relieve the pressure
from pump 1.
Check the length “L”.
Dismount the pumps and the dial gauge.
Tighten the nut to contact with the actuator.
Secure the rudderstock nut.
DISMOUNTING:
1. Dismount the lock plate.
2. Unscrew the nut to the length (L+2) mm. See the table.
3. Mount pump 1 for oil pressure to the nut, and pump 2 for
oil-pressure to the taper.
4. Increase the oil-pressure from pump 1bar to 50bar.
5. Increase the pressure on the taper (pump 2) gradually until
the pressure in the nut (pump 1) is rising. This indicates that
the taper is “floating”.
6. Reduce the pressure from pump 1 gradually without
reducing the taper pressure (from pump 2), and the
rudderstock will be released from rudder actuator.
PREPARATION:
The stuffing box should be mounted on a leveled deck, in order to
avoid sea water from penetrating between stuffing box housing and
deck a separate seal between deck and housing to be used. A seal
for this purpose is supplied with the stuffing box. The maximum
curvature on the leveled deck when using this seal is 1 mm across
the stuffing box surface.
INSTALLATION:
1. Mount the split stuffing box around the rudderstock by using
specified bolts.
2. Prepare the ring for installation in the housing as follows:
The seal is delivered in on piece (split), the spring is also
delivered in one piece (forming a closed circle). In order to
proceed, the spring will have to be opened by turning one end
CCW (about 4-5 turns). When opening the spring, please
observe the “twist” (torsion) set up in the spring.
After the parts have been dismounted, place the spring
around the rudderstock and turn one end CCW 4-5 turns (when in
open position). Close the spring by screwing the ends together and
tighten them. Please see sketch above showing enlarged copy of
spring ends.
In order to make a perfectly circular shape, hand
shape the spring joint by applying hand pressure to the joint after
the spring is closed. This is required in order to make a circular
shape of the inner threaded part of the joint the length of this
threaded part will be approx. 30-40 mm.
3. Place the seal around the rudderstock at a level above the spring.
Press the spring into the groove of the seal. The spring is elastic,
and will be easy to install into the seal groove after the spring is
closed. Note! Lubricate seals with grease at installation.
4. Press the seal with the mounted spring into the stuffing box
housing.
5. Repeat step 1-4 for ring no2.
6. Place retaining plate on the top of housing and tighten the hex of
head screw. Please also refer to assembly drawing of stuffing box
for further details.
SEAL LUBRICATION: A liberal lubrication during assembly will ensure lubrication from
the start. During operation seals should be checked on a weekly
basis and grease added once a month as necessary. Please also
refer to sketch on page one for lubrication during assembly.
System overview for steering gear with solenoid operated
valves.
EMERGENCY SETTING:
STEERING GEAR, SOLENOID OPERATED PUMPS
FROM BRIDGE:
The main control is normally supplied with non-follow-up push
buttons for emergency steering.
The non-follow-up push buttons are often equipped with so that
other steering modes are disconnected when the steering is
operated. If the priority steering is used a audible alarm will be
activated, the alarm can be reset with the “buzzer release” push
button.
To regain normal steering turn the override switch is in position
“override”.
FROM STEERING GEAR ROOM:
The maneuvering valves on the rudder motor can be operated
manually by use of the emergency device on the solenoids. The
selector switches on the motor controller must be turned to position
“Local Control”.
Hand-hydraulic emergency steering pump is installed is usually
situated in the steering gear room. In order to operate this pump the
cocks for connecting the pump must be opened
RUDDER INDICATION SYSTEM:
Consult section for control station and feed back unit.
The rudder indicator amplifier is normally located at the
terminal list on the main control panel
Adjustment of the mechanical zero point of the rudder
indicator.
- Check that all rudder indicators indicates 0 degrees
without power supply connected,(factory setting).
- Switch on the power supply to the indicator
system.
- Check that the rudder and mechanical rudder
indicator on the actuator is in zero position
- If the rudder indicators not is indicating zero
position a final zero adjustment (P20) (+- 2
degrees) can be done on the rudder indicator
amplifier.
- Operate the rudder actuator manually from the
steering gear room until the mechanical rudder
indicator reaches 35 degrees port. Adjust the gain
(P30) on the rudder amplifier until the rudder
indicator show 35 degrees port. Each of the rudder
indicators can also be adjusted separately if
necessary.
- Adjustment of galvanic isolated +- 10V rudder
position signal. Position the rudder 5 degrees before
the steering gear reach mechanical stop and adjust
(P40) until the rudder position signal equal 9V.
CONCLUSION:
From the STUDY OF RUDDER AND RUDDERSTOCK WITH
STEERING GEAR MECHANISM we can conclude that rudder
is used in turning of a ship in directions of port and starboard
within the requirements. Other than this, the rudder force has
another effect on the ship. It creates a moment about the centre of
gravity of the ship and also gives strength to aft portion of ships. It
is cleared that rudder is always present aft portion(i.e. stern side) of
the ships but not on the front portion of ships(i.e. bow side)
because there will be a problem of damage to rudder due to
collisions and also rudder is placed behind the propeller because it
increases velocity of flow of water.
REFERENCES:
1. “Good Light” ship construction live project in Hindustan
shipyard limited.
2. “Balwan” ship construction live project in Hindustan shipyard
limited.
3. “Good trade” ship construction live project in Hindustan
shipyard limited.
4. “Saahak” ship construction live project in Hindustan shipyard
limited.