Marine Auxiliary
Marine Auxiliary
Machinery
Machinery
Chapter 9
Chapter 9
Steering Gear
Steering Gear
By Professor Zhao Zai Li
By Professor Zhao Zai Li
05.2006 05.2006
Marine Auxiliary
Marine Auxiliary
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Rudder Arrangement
Rudder Arrangement
By Professor Zhao Zai Li
By Professor Zhao Zai Li
05.2006
05.2006
Learning Objectives
Learning Objectives
Know the parameters essential for the
Know the parameters essential for the
size of the steering gear.
size of the steering gear.
Be able to explain how the
Be able to explain how the
bearing
bearing
forces act
forces act
Know the principles of the most used
Know the principles of the most used
rudder arrangements.
rudder arrangements.
Rudder Torque
Rudder Torque
In order to move the rudder, theIn order to move the rudder, the
steering gear has to create a
steering gear has to create a
certain torque (measured in kilo
certain torque (measured in kilo
Newton)
Newton)
The torque requirement isThe torque requirement is
given by the class rules to
given by the class rules to
ensure safe maneuverability of
ensure safe maneuverability of
the vessel. The size and also the
the vessel. The size and also the
speed of the vessel is taken into
speed of the vessel is taken into
consideration.
consideration.
Rudder Forces
Rudder Forces
The rudder arrangement
The rudder arrangement
is also exposed to these
is also exposed to these
forces:
forces:
-Current forces created by-Current forces created by
propeller and waves
propeller and waves
-Gravity of components-Gravity of components
and ship movement
and ship movement
-Side forces when turning-Side forces when turning
The forces depend upon
The forces depend upon
the type and size of
the type and size of
rudder and also the
rudder and also the
Spade rudder
Spade rudder
This is the most usedThis is the most used
rudder type on ferries and
rudder type on ferries and
smaller boats. This type
smaller boats. This type
of rudder gives very
of rudder gives very
good manoeuvrability,
good manoeuvrability,
depending on the
depending on the
available rudder angle
available rudder angle
and the rudder profile.
Half Speed Rudder
Half Speed Rudder
This type of rudder isThis type of rudder is
most commonly used
most commonly used
on big vessel. This
on big vessel. This
rudder is not spade
rudder is not spade
rudder of the same
rudder of the same
size.
size.
Flap Rudder
Flap Rudder
This type of rudder isThis type of rudder is
used when very good
used when very good
man
manoeuoeuvravrabilbilityity isis
required. The rear fin
required. The rear fin
“exa
“exaggeraggerates”tes”thethe
movement of the
movement of the
rudder, making the
rudder, making the
rudder more effective.
rudder more effective.
(increasing the side
(increasing the side
lift) lift)
Assessment Test
Assessment Test
Question 1 of 3
Question 1 of 3
The water flow creates?
The water flow creates?
A) Vertical forces on the rudderA) Vertical forces on the rudder
B) Side forces on the rudderB) Side forces on the rudder
C) Both vertical and side forcesC) Both vertical and side forces
D)I don’t knowD)I don’t know
Assessment Test
Assessment Test
Question 2 of 3
Question 2 of 3
What are the parameters most essential for the
What are the parameters most essential for the
rudder torque?
rudder torque?
A) Shape of the hill, propeller rotation and wavesA) Shape of the hill, propeller rotation and waves
B) Rudder arrangement, size of the rudder and theB) Rudder arrangement, size of the rudder and the
vessel’s speed
vessel’s speed
C) The vessel’s dead weight and tonnageC) The vessel’s dead weight and tonnage
D) I don’t knowD) I don’t know
Assessment Test
Assessment Test
Question 3 of 3
Question 3 of 3
Which one of these three rudders gives the best
Which one of these three rudders gives the best
manoeuvrability, given they have the same size?
manoeuvrability, given they have the same size?
A) Spade rudder with normal profileA) Spade rudder with normal profile
B) Semi-spade rudderB) Semi-spade rudder
C) Flap rudderC) Flap rudder
D) I don’t knowD) I don’t know
Marine Auxiliary
Marine Auxiliary
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Actuator Working
Actuator Working
Principles
Principles
By Professor Zhao Zai Li
Learning objectives
The working principles of the standard model of the
rotary vane actuator
The working principles of the RAM model actuator
2 Actuator Working Principles
Basically there are two types of electro hydraulic steering gear working principals:
The ram (or cylinder)
type and the rotary vane type.
Ram Actuator
Ram Actuator
The working principles ofthe two are very similar. A strong slow movement of a mechanical surface is created by the use of high oil pressure.
Ram type uses cylinder pistons
Rotary vane uses pressure working on the side of a vane (or wing)
Ram Actuator
On the ram type thepiston is connected by a ram (or rod ) to a tiller, and the tiller is fixed connected to the rudder stock, creating the rotating movement. On the rotary vane the vane is fixed to a boss (hub) that is fixed directly to the stock.
Ram Actuator
The principles as described forthe Porsgrunn rotary vane steering gear can easily bi transformed to the ram type. Typical for ram type steering gears is that they work with a much higher hydraulic pressure, they need an external rudder stock bearing and the working angle is limited, compared with the rotary vane steering gear.
Standard Model
The standard model is used on:
All vessels except tankers with single
rudder installation above 100,000DWT
Safety:
Safety against single failure on the
hydraulic system, according to SOLAS rules.
Working principle of the
standard model
We will now show you a schematic drawing of the steering gear.
The model shows a normal operation situation, with one pump running. Using both pumps will double the speed of the rudder.
Working principle of the
standard model
Assessment Test
Question 1 of 5
When shall both power units be in use?
A) All the time
B) When navigation demand special caution
C) When the ship is less than four nautical miles from
shore
D) I don’t know
Assessment Test
Question 2 of 5
What is the limit in size for tankers to use only
one standard steering gear?
A) 10,000GT (gross tonnage) B) 100,000DWT(deadweight tons) C) 100,000NT (net tonnage) D) I don’t know
Assessment Test
Question 3 of 5
What is the purpose of the safety valve?.
A) To protect against leakage between the p ressure
chambers
B) To protect the actuator against too high oil
pressure.
C) To protect the vanes from breaking D) I don’t know
Assessment Test
Question 4 of 5
One of the statements below is not correct, which
one?
A) Both rotary vane and ram steering gears are of electro
hydraulic type.
B) The ram type must have a separate external rudder
stock upper bearing. This is not necessary for a rotary vane type
C) The ram type steering gears generally work with a
lower oil pressure than a rotary vane
Assessment Test
Question 5 of 5
How is the movement of the actuator created?
A) By starting the motors on both power units B) By actuating the direction valve and the safety C) Start at least one power unit and actuate the direction
valve
D) I don’t know
Marine Auxiliary
Machinery
Chapter 9
Lesson 3
Actuator Main Parts
By Professor Zhao Zai Li 05.2006
3
Actuator Main Parts
Identify and understand the function of the main
parts of the actuator:
Housing Rotor Stoppers Cover Radial bearing Rudder carrier
Actuator basics
The actuator is situated on top of the rudder stock in the steering gear
compartment. The rotor in the rotary vane actuator is mounted directly on the rudder stock.
The rudder stock connects the actuator with the rudder.
The Actuator
Rudderstock Bearings
The Actuator
Actuator Main Parts
1.Angel indicator
This is fixed to the rudderstock and shows the rudder angel.
2. Expansion tank
This tank serves as an expansion tank for the system oil.
3. Rudder stock nut
This nut acts as a securing device for the friction connection between the rudderstock and the rotor.
4.Stoppers bolt nut
Making boundaries for the pressure chambers and also sets the limits for the rudder angle to each side.
5. Upper radial bearing
The upper radial bearing takes up radial forces in
conjunction with lower radial bearing .It is made of brass . This bearing is lubricated by the system oil .
6. Rotor hub
This is the moving part of the actuator . It turns the rudderstock when the hydraulic pressure increases on either side of its vanes. It is fitted with spring loaded cast iron bars (dynamic seals). These are not exposed to wear.
7. Housing
Serves as the outer boundaries, side and bottom of the pressure chambers .
8. Rudder stock
This is the connecting shaft between the rotor and the rudder.
9. Lower Radial bearing
The lower radial bearing takes up radial forces in conjunction with upper radial bearing. It is made of brass. This bearing is lubricated by the system oil.
10. Rudder carrier
This bearing carries the weight of the moving parts of the steering gear including the rudder. I t also takes up the axial forces that waves and propellers can make. This bearing is made of brass. This bearing is lubricated by the system oil.
11. Lower packing
This keeps the system oil from leaking down the rudderstock oil has lubricated the lower side bearing and the rudder carrier.
12. Ring jack
This is used during installation, to force the rotor onto the rudder stock.
13. Cover
The cover forms the top of the pressure chambers.
Assessment Test
Question 1 of 4
What are the bearing made of ?
A) Steel B) Copper C) Brass D) I don’t know
Assessment Test
Question 2 of 4
What is the main purpose of the housing. stoppers
and cover?
A) Making boundaries for the pressure chambers. B) Protecting the rotor.
C) Interfacing between the steering system and the ships
hull structure.
D) I don’t know
Assessment Test
Question 3 of 4
How is the rotor fixed to the rudderstock?
A). By two keys.
B). Combination of one key and friction. C). By friction only.
D).I don’t know
Assessment Test
Question 4 of 4
What are the bearings lubricated with?
A) Grease
B) Separate oil system C) The system oil D).I don’t know
Marine Auxiliary
Machinery
Chapter 9
Lesson 4
Steering and Control System
By Professor Zhao Zai Li05.2006
4 Steering and Control System
Learning objectives
Identify system components: Actuator
Motor starters
Start/Stop/Alarm control panels Rudder angle indicators
Know the different type of steering modes:
Use of autopilot Follow-up steering
Non follow-up steering (NFU)
System components
Wheel house Engine control room Steering gearWheel house
The main control panel is in the wheelhouse. This control panel features the start/stop and the Alarms/Signals and
acknowledgment of alarms.
Wheel house
In the wheelhouse ceiling there is a Panorama 3-way rudder angle indicator. There is often also two rudder angle indicators, one on each bridge wing. This is a very common remote rudder angle indication system, but there may be other indicators as well according to the ship owner’s requirements.
Engine control room
In the Engine Control Room there is an Alarm/Signal Panel. According to normal standards, and to avoid possible misunderstandings it should not be possible to op erate the steering gear from this control stand.
Steering gear
On the top of the actuator there is a scale with degrees, showing the angle of the rudder to port/ starboard, and also signal transmitters and feed-backs for remote rudder indication and steering control system.
Steering gear
An auxiliary steering gear is not required according to the rules, because the power units are regarded as back-up for each other.
Steering modes
Three most used steering modes.
Non follow-up (Manual)
A variant of Manual called Follow-up Autopilot
.
Non Follow-up (manual)
Non Follow-up is totally manual control of the rudder movement, from wheel-house or, in emergency situations, from the steering gear compartment.
Follow-up and
Autopilot
Follow-up
Follow-up mode is a variant of manual, it allows the
rudder to be locked in any rudder angle, and the system will hold it there until you move it again.
Autopilot
The ship will automatically find its way to a pre-set
position point along a pre-set route. If the ship is forced out of course, the autopilot will use the rudder to get the ship back on course
Assessment Test
Question 1 of 3
Where are the remote rudder angle indicators most
often located?
A) At the bridge
C) In various places around the ship B) In various places around the ship D) I don’t know
Assessment Test
Question 2 of 3
The steering mode, in which the rudder angle is
pre-set manually and kept in position automatically
is called?
A) Auto pilot mode B) Non follow up C) Follow up D).I don’t know
Assessment Test
Question 3 of 3
In case of any steering gear alarm occurs this can
only be acknowledged from?
A) The steering gear compartment B) The engine control room C) The wheel house D).I don’t know
Marine Auxiliary
Machinery
Chapter 9
Lesson 5
Safety rules and regulations
By Professor Zhao Zai Li05.2006
Marine Auxiliary
Machinery
Chapter 9
Lesson 5
Safety rules and regulations
By Professor Zhao Zai Li 05.2006
5 Safety rules and regulations
Learning objectives
Rules in general
Requirements concerning the steering gear SOLAS 1997,chapter V, Regulation 19-2.
The Rules in general
This is the administrative
hierarchy that has been
established by the United
Nations in order to develop an
standard of rules covering
maritime matters.
United Nations
United Nations headquarters in
IMO and SOLAS
IMO
International maritime organization.
This committee consists of representatives from all the member countries. IMO made the SOLAS
SOLAS
Safety of lives at seas.
A comprehensive set of rules made by IMO to ensure safety at sea.
Class rules
These are rules set by the class
companies
Such as:
DNV-Det norsk veritas (N)
LRS-Lloyds Register of shipping (GB) ABS-American Bureau of shipping (USA) GL-Germanischer Lloyd (D)
And others
Speed of rudder
For regular ships the rudder must be able to turn minimum 35 degrees to each sides. To meet the rules concerning rudder angle velocity, the rudder must be able to turn from 35 degrees to 30 degrees on the other side in maximum 28 seconds. This is called the minimum angle velocity.
Torque capacity
The steering gear must be big enough to turn the rudder to 25 degrees port and starboard at full speed (Ruder torque/Maximum working torque). This torque is achieved at a certain oil pressure working on the vanes of the rotor.
The safety valve is set at a corresponding oil pressure
minimum 25% above this. when the safety valves open the oil is allowed to by-pass the vanes.
Torque capacity
In addition the steering gear is to be pressure tested with a much higher pressure. This is done by the manufacturer before delivery.
The hydraulic system should be designed so that “single failure” doesn't put the steering gear out of function.
Placing of emergency scheme
The procedure diagram for emergency steering should be easily seen in the wheel house and steering gear
Placing of emergency scheme
The emergency steering is done by the use of non-follow up push buttons on the starter cabinet or directly on the directional valves on the steering gear.
System alarms
The system shall be looked after by monitoring important functions specified in the rules such as oil levels and power supply. The monitoring is done by placing sensors in important areas. These sensors, either one by or in combinations, activate different alarms.
System alarms
The operator of the steering gear must have the
necessary competence. the steering gear vital functions are to be regular checked by the crew and the crew are to be drilled in emergency procedures.
The SOLAS rules
5.3.4regulation19-1
Operation of steering gear
In areas where navigation demands special caution, ships shall have more than one power unit in operation when such units are capable of simultaneous operation.
The SOLAS rules
5.3.4regulation19-2
Steering gear: Testing and drills
(a) within 12h before departure, the ship's steering gear shall be checked and tested by the ship crew. The test procedure shall include, where applicable, the operation of the following:
(i) the main steering gear;
(ii) the auxiliary steering gear;
(iii) the remote steering gear control systems;
The SOLAS rules
(iv) the steering positions located on the navigation
bridge;
(v) the emergency power supply;
(vi) the rudder angle indicators in relation to the actual
position of the rudder;
(vii) the remote steering gear control system power
failure alarms;
(viii) the steering gear power unit failure alarms; (ix) automatic isolating arrangements and other
The SOLAS rules II
(b) The checks and tests shall include:
(i) the full movement of the rudder according to the required capabilities of the steering gear;
(ii) a visual inspection of the steering gear and its connecting linkage; and
(iii) the operation of the means of communication between the Navigation Bridge and steering gear compartment.
The SOLAS rules II
(c) (i) Simple operating instructions with a block diagram showing the change-over procedures For remote steering gear control systems and steering gear power units shall be permanently displayed on the Navigation Bridge and in the steering gear compartment.
(ii) All ships officers concerned with the operation or maintenance of steering gear shall be Familiar with the operation of the steering systems fitted on the ship and with the procedures for change from one system to another.
The SOLAS rules II
(d) In addition to the routine checks and tests prescribed in every three months in order to practise emergency steering gear procedures. These drills shall include direct control from From within the steering gear compartment, the communications procedures with the Navigation Bridge and, where applicable, the operation of the alternative power supplies.
The SOLAS rules II
(e) The Administration may waive the requirement to carry out the checks and tests Prescribed in paragraphs (a) and (b) for ships which regularly engage on voyages of short Duration. such ships shall carry out these checks and tests at least once every week.
(f) The date upon which the checks and tests prescribed in paragraphs (a) and (b) are carried out and the date and details of emergency steering gear drills carried out under paragraphs (d) shall be recorded in the log-book as may be prescribed by the Administration.
Assessment Tests
Question 1 of 3
According to the SOLAS rules the rudder angle
velocity should be at least 35-0-30degrees in
maximum 28 seconds for.
A) all cargo ships above 10,000DWT or passenger ships carrying more than 50 passenger.
B) regular ships, other requirements for special ships.
C) all ships using one steering gear power unit.
D) I don't know.
Assessment Tests
Question 2 of 3
The steering gear's maximum working torque is:
A The effective torque at the safety valve opening pressure
B) At least the torque necessary to turn the rudder to the maximum required angle at the vessel's full speed according to the class rules
C) The maximum torque to be created by the steering gear, according to the makers experience
Assessment Tests
Question 3 of 3
According to the SOLAS rules the maximum rudder
angle to port and starboard should be at least:
A) 45 degrees
B) 35 degrees
C) 35 degrees, but 25 degrees only if special high efficient ruder is installed D) I don't know.
Marine Auxiliary
Machinery
Chapter 9
Lesson 6
Operation
By Professor Zhao Zai Li 05.2006
6 Operation
Learning objectives
Starting and stopping of the power units from the
wheelhouse
The meaning of the different alarms What action to be taken in case of alarms
Control Panel
The WH panel is the main control panel of the steering gear functions and alarms. Normally under sea going conditions all orders related to the steering gear should be given from the bridge.
Alarm scenarios
CASE1 One power unit running the other in stand by,
an alarm occurs:
The steering gear system will then automatically start the
standby power unit, and the power unit with the alarm stops.
CASE2 Two power units running, an alarm occurs
on one of them:
automatically stop the power unit the alarm.
Alarm scenarios
CASE3 One power unit running the other is not in
stand by, an alarm occurs on the running unit:
The steering gear system will then let the power unit with the alarm run unit stops (damaged)
Control panel info
The steering gear is now ready for control from the wheel house. Before you start you should push the lamp test button, and adjust the dimmer if necessary. An alarm indicates an abnormal situation by a flashing lamp and a buzzing sound.
Assessment Tests
Question 1 of 3
According to the SOLAS rules the rudder angle velocity
should be at least 35-0-30degrees in maximum 28 seconds
for.
A) The stand by power unit will start automatically.
B) The motor stops to cool off and starts automatically up again
when the temperature is normal.
C) The motor will get damage if the acknowledge buttons is not
Pushed immediately.
D) I don't know.
Assessment Tests
Question 2 of 3
When is the steering gear ready for turning the
rudder controlled from the wheel house?
A) "steering control ready WH“ and "run" On at least
one of the power units.
B) "steering control ready WH" +"stand-by“ on both
power units.
C) "Overload"+ "filter clogged"+ "Lamp Test" D) I don't know.
Assessment Tests
Question 3 of 3
What is the purpose of the acknowledge function:
A) Tell the system that the alarm is registered. B) Tell the system that the problem is solved. C) Tell the system to ignore the alarm and continue to
operate as normal.
D) I don't know.
Chapter7 Emergency Steering
Learning objectives
Know what could cause an emergency situation Know what to do when an emergency situation occurs Be able to locate the valves on the actuator
Control Panel
Emergency steering is the same as local steering from the steering gear compartment. The operator has to push directly on the valves on the actuator and keep his eyes on the rudder angle indicator wheel on the top of the actuator. Rudder commands (degrees to starboard or port) are to be received by phone from the bridge. local steering can also be done from the starter cabinet's front panel (Non-follow-up-buttons).
Causes for emergency situations
Same situations in
which local steering
may be necessary:
Failure on the ruder or
rudder indication system.
Bridge out of function Cable breakage
In case of emergency
It is extremely important that the procedure for switching over to local steering mode is well know and drilled, so everyone involved know what to do. This is described in detail on the "OPERATING INSTRUCTION" diagram, which is hanging on the bulkhead in the wheelhouse and in the steering gear compartment.
In case of emergency
you should study this “OPERATING INSTRUCTION” diagram on your vessel and go down to the steering gear compartment to get familiar with the emergency steering controls. The controls may vary on different types of steering gear.
Operating Instruction
OPERATING INSTRUCTION of STEERING GEAR
Assessment Tests
Question 1 of 3
Which type of valves are actuated in case of local
steering ?
A) Direction valves B) Safety valves C) Connecting valves D) I don't know.Assessment Tests
Question 2 of 3
Which one of the situations described below may
cause the need fir local steering ?
A) Failure on the auto pilot B) Failure on the follow up system C) Bridge out of function
D) I don't know.
Assessment Tests
Question 3 of 3
The vessel is offshore on the steady course and order
to switch over to local steering is given. What
knowledge will you need in particular?
A) How to handle emergency situation in general B) How to prevent damage on the rudder and steering
gear
C) What you have learn from the OPERATING
INSTRUCTIONS And drilling the emergency procedures
D) I don't know.
Marine Auxiliary
Machinery
Chapter 9
Lesson 7
Maintenance
By Professor Zhao Zai Li 05.2006
Chapter 7 Maintenance
Learning objectives
To maintain trouble free operation you should know the
different service intervals and what tasks are to be performed at each level, and by whom.
Maintenance on Board
The maintenance intervals are divided into:
1 Daily 2 Monthly
3 Class (5 years) /Makers recommendation
These are the tasks that should be perform at the
different stages.
Daily:
1 check oil /oil level 2 check for leakage 3 check for abnormal noise
Maintenance on board
Monthly
1. Thorough visual inspection of each component and
indicators.
2. Check all fittings and connections that may come lose
under operation. Tighten the nuts and bolts where necessary
3. Check typical wear parts and replace actual part 4. Complete functional testing
5. Test of emergency steering procedure.
6. Check the condition and amount of pollution in the oil.
Flush the system if necessary, and replace the oil (normally every second years)
Daily and monthly inspection is carried out by the
ship’s crew.
Heavier jobs
Class inspection
1. The steering gear shall be classed regularly like the rest of the
ship
When the ship is in dry dock for class inspection, we
suggest a thorough inspection / service
1. Change of actuator bearings that are whom to bigger
tolerances than allowed or soon will be.
2. Change all important parts that may be exposed to wear or
ageing. This will also include the system oil.
Heavier jobs
If the rudder has hit bottom (grouping) during the
last period, even if it seems to work well, the
actuator should be opened and checked anyway.
A service engineer from the manufacturer should carry
out maintenance on the actuator
.
Assessment Tests
Question 1 of 2
The actuator bearings should be checked
A) Daily B) Monthly
C) Every 5 years, or after grouping D) I don't know.
Assessment Tests
Question 2 of 2
Heavy jobs on the steering gear should be done by:
A) Anyone who claims to be an expert on hydraulic
components.
B) The chief engineer
C) A service engineer from the steering gear
manufacturer D) I don't know.
Marine Auxiliary
Machinery
Chapter 9
Lesson 9
Spare Parts
Chapter 9
Spare Parts
Learning objectives
learn the different levels of spare parts.
Maintenance on Board
Use of correct spare parts is essential for trouble free operation of the steering gear.
It is very difficult or impossible to predict the exact life of a part exposed to wear, or age.
What parts that are to be kept on board depend on what level of safety the ship operator w ants.
Maintenance on Board
The safety policy can be divided into three readiness
levels:
1 Basic level
This level meets the minimum class requirement
.
2 Essential spare parts:
Essential spare parts are classed as follows: Every part
exposed to wear or ageing and for which a defect may cause critical failure. (Critical failure: steering gear partly or complete out of function ).
Maintenance on Board
3 Maker’s recommendations
:
Keeping all essential and necessary parts on board to
perform planned maintenance and keep off-hire to a minimum.
By the use of makers experience and knowing which level
of safety the owner wants, the makers should always be able to supply a suitable package of spares. Fo r older steering gears (more than 15-20years of age ) every part should be taken into consideration because of a possible long delivery time.
Assessment Tests
Question 1 of 3
Which of the parts mentioned below are normally
not exposed to wear or ageing?
A) Static rubber seals B) Relays and sensors C) Cast iron sealing bars D) I don't know.
Assessment Tests
Question 2 of 3
Which of the statements below belongs to porsgrunn
spare parts policy?
A) Essential spare parts are to be kept on stock. B) All spare parts are to be kept on stock.
C) No spare parts for steering gears older than 30 years. D) I don't know.
Assessment Tests
Question 3 of 3
Which of the factors do you believe will not affect the
lifetime of the brass bearings in the actuator:
A) Rudder arrangement and alignment of rudder stock
from the steering gear installation.
B) Pureness of the oil..
C) No spare parts for steering gears older than 30 years. D) I don't know.
