Project report on ship rudder

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.



N. Teja (121FA08048)


.

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)


N. Teja (121FA08048)









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:



N. Teja (121FA08048)









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.