Description
Maker: Kawasaki-Wuhan Type: FE21-064-T050
The steering gear consists of four hydraulic rams driven by two electrically driven pumps. The pumps are of the variable displacement axial piston type and are contained in their own individual oil tanks.
The steering gear is capable of operating as two totally isolated steering systems.
Each pump unit is capable of putting the rudder through the working angle in the specified time. The second pump unit can be connected at any time by starting the motor.
The steering gear is provided with an automatic isolation system. Both hydraulic systems are interconnected by means of electrically operated isolating valves that in normal operation allow both systems together to produce the torque necessary for moving the rudder. In the event of failure that results in a loss of hydraulic fluid from one of the systems, the float switches in the expansion tank are actuated. This gives a signal to the isolation system, which automatically divides the steering gear into two individual systems. The defective system is isolated, whilst the intact system remains fully operational, so that steering capability is maintained at reduced speed with 50% of the rudder torque.
The steering gear is remotely controlled by the auto-pilot control or by hand steering from the wheelhouse. All orders from the bridge to the steering compartment are transmitted electrically. Steering gear feedback transmitters supply the actual position signal for the systems. The rudder angle is limited to 35° port or starboard.
The variable-flow pumps are operated by a control lever, which activates the tilting lever of the pump cylinder. This causes oil to be discharged to the hydraulic cylinders. When the tiller reaches the set angle, the tilting lever is restored to the neutral position, which causes the pump to cease discharging.
No.1 pump unit is supplied with electric power from the emergency switchboard and the other pump unit from the main switchboard.
Under normal circumstances, all four cylinders will be in use, with one pump unit running and the second pump unit ready to start automatically. When manoeuvring or steaming in confined waters, it is compulsory that both pump units are running, in order to get the IMO recommended tiller movement of 35°
on one side to 30° the other side within 28 seconds (with one pump in 56 seconds).
Procedure to Put the Steering Gear into Operation.
The system valves are assumed set for normal operation.
a) Check the level and condition of the oil in the tanks and refill with the correct grade as required.
b) Check that the pin in the control lever is correctly fitted.
c) Ensure the rudder is in the mid position.
d) Start the selected electro-hydraulic pump unit.
e) Carry out pre-departure tests.
f) Check for any leakage and rectify.
g) Check for abnormal noise.
h) Check operating pressures.
Automatic Isolation System Description
This steering gear is so arranged that in the event of a loss of hydraulic fluid from one system, the loss can be detected and the defective system automati-cally isolated within 45 seconds. This allows the other actuating system to remain fully operational with 50% torque available.
Construction
This system consists of the following equipment:
2 - Isolating valves
2 - Level switches with ‘LOW’ & ‘LOW-LOW’ level positions 2 - Oil tanks having a chamber for level switches and system test
valves
Electric control panel for automatic isolation system Alarm panel for automatic isolation system
Operation
If failure of one of the systems occurs, the ship's speed should be reduced, as only 50% of the torque for the steering gear operation is available.
Failure sequence with one pump running
If loss of oil occurs, with No.1 pump running and No.2 pump stopped, the following sequence will take place:
1. If the oil level in No.1 oil tank goes down to the ‘LOW’ position audible and visual alarms are given on the navigating bridge and in the machinery space.
2. No.1 isolating valve (IV - 1) is energised and the hydraulic system associated with No.2 pump is isolated.
3. If the oil level goes down to ‘LOW-LOW’ position:No.1 isolating valve (IV-1) is de-energised and No.1 pump is automatically stopped; No.2 isolating valve (IV-2) is energised and No.2 pump is automatically started. The hydraulic system associated with No.1 pump is isolated. Steering is now carried out by No.2 pump and its two related cylinders (No.3 & No.4).
4. If the oil loss occurs in No.2 tank, steering continues to be carried out by No.1 pump and its two related cylinders (No.1 &. No.2) with 50% torque.
If No.2 pump is running and No.1 pump is stopped, No.1 and No.2 pumps and No.1 and No.2 isolating valves are reversed in the above sequence.
Failure sequence with both pumps running.
If the oil level in No.1 or No.2 oil tank goes down to the ‘LOW-LOW’ level, the associated isolating valve will operate and the respective pump will be automatically stopped.
System testing
The float chamber can be isolated and drained to test the system operation.
This should be carried out as part of the pre-departure checks.
Illustration 2.11b Emergency Steering
Control Panel for Steering Gear Servo - Motors
Buttons to move Steering Gear either Port or Starboard
Push in and lock this Button Control Valve Block showing Bypass Buttons
Emergency Steering
If failure occurs in the remote operating system from the wheelhouse, the steering can be operated from the trick wheel in the steering gear room.
Description
The steering gear consists of a tiller, turned by a four cylinder hydraulic system, that in turn is driven by two electric motors. In accordance with IMO regulations the pumps, hydraulic power circuits and rams can operate as two isolated systems.
The steering gear is fitted with an automatic isolation system. This system is used to divide the hydraulic power circuits in the event of a hydraulic oil loss from the oil tanks.
In accordance with IMO regulations the hydraulic pumps used in the steering gear are supplied with power from two independent sources. In the event of power failure from the main switchboard, one pump can be supplied from the emergency switchboard.
Procedure for Operation of Steering Gear on Loss of Remote Bridge Control
a) On loss of steering gear control from the bridge, establish communica-tion with the bridge via the telephone system. A telephone is located on the steering gear compartment platform.
Indication of the rudder angle and a compass repeater are provided for manual control of the steering gear.
See Illustration 2.11b
b) Turn ‘local/remote’ control switch to local control.
This switch is on the ‘No Follow Up’ panel on the starboard side of the steering gear room.
c) Operate the push buttons ‘Port’ or ‘Starboard’ to turn the steering gear in the direction request by the bridge.
If this system should fail, manual operation can be carried out as follows:
a) Switch off the torque motor power.
b) Push in the button ‘A’ and screw lock in place.
c) The tiller can be moved in accordance with the steering command from the bridge by turning the torque motor shaft knob.
The pumps and associated equipment are operated as normal.
Emergency Steering Drill
Emergency steering drill should be carried out at least once every three months when traffic and navigational restrictions permit.
It is to consist of the direct operation of the main steering gear by using the manual control within the steering flat. This operation is to be directed from the navigation bridge. After each drill, details and the date it was carried out are to be entered in the Official Log Book and Particulars and Records Book.
Illustration 2.12.1a Diesel Generator - General Arrangement
Engine
Type: 7L23/30H
Maker: Holeby - Man - B&W.
Alternator
Maker: Hyundai Type: HFJ6 566 208 Capacity: 1137.5kVA
Hours L.O. Pressure
D.C. Voltmeter
Circuit Breaker Push to Reset Manual StartStart
Off Run Crank Idle
Run Engine SpeedL.O. Temperature
C.W. Temperature TACH ENGINE INSTRUMENT PANEL
Engine Speed
TACH Engine Speed
TACH
Engine Speed
TACH Engine Speed
TACH
Engine Speed
TACH Engine Speed
TACH
2.12 Electrical Power Generators