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Q5. A. Examine in detail three common but entirely different reasons for loss of steering gear systems. B. State how failure is inhibited in the design, operation and maintenance of steering gear systems C. Describe how a vessel may make port upon irreparable failure of the steering telemotor

Q3. Explain vapor compression refrigeration cycle on T-S and PH diagram and explain the purpose of EACH of the following:

(a) Expansion valve

(b) Room thermostat

(c) High pressure cut out.

(d) Equalizing line.

Q8. In a Rotary vane steering gear, briefly state.

a) How are the fixed and moving vanes attached to cylinder and rotor respectively.

b) How many sets of vanes are provided? What is the limitation factor to number of vanes.

c) How is strength imparted to moving vanes to enable them to act as rudder stops?

d) How is rudder uplift accommodated?

Q2. a) Sketch and describe a high pressure cut-out in a refrigeration system. (6)

b) The refrigeration compressor has stopped due to operation of the H.P. cut-out.

Explain: (i) The possible causes. (3)

b) How these causes would be found and possible remedies. (3)

c) What steps are taken if the compressor “Short-cycle” on low pressure cut-out? (4)

Q4. With reference to electrohydraulic steering gear systems with four Rams,

(a) With the aid of a sketch describe the working principle of hydraulic pump. (8)

(b) Explain the method adopted to prevent hydraulic oil leakage along the rams (4)

(c) Discuss the methods adopted to prevent damage to the steering gear due to jumping of rudder in heavy seas. (4)

Q6. “With reference to a four-ram hydraulic gear”, having duplicate pumps-

a) Sketch the arrangements of relief, make up, isolating and by-pass valves. (8)

b) Explain the use of isolating and by-pass valves, if one of the cylinders has fractured. (4)

c) Describe the arrangement provided to indicate the loss of hydraulic fluid due to leakage. (4)

Q4. a) As per SOLAS regulations, what checks and tests must be carried out on the steering gear system before the ship’s departure from port? Explain the procedures involved and the documentation required. (8)

b) Explain the construction, working, and purpose of hunting gear in a steering gear system. What are the consequence of its failure? (8)

Q6. With reference to electro-hydraulic steering gears:

A. Explain in terms of control parlance, the function of the “Hunting gear”;

B. Explain the consequences if the standby pumping unit is motored;

C. State TWO methods employed to prevent the standby hydraulic pump being motored by the operating unit.

Q5. Sketch and describe the operation of a four ram electro-hydraulic steering gear system. Indicate and explain the valve positions for the operation of the system when one pump is isolated, and the unit is operating on two rams only.

Q4. With reference to hydraulic steering gears, sketch and describe each of the following: (A)Single failure concept;

(B)100 Percent redundancy.

Q6. Sketch and describe a “fail safe steering gear” suitable for use on a tanker of more than 100,000 T dwt; Explain the sequence of events that take place when an oil leak takes place in one of the hydraulic pipe lines.

Q3. A. Describe with the aid of sketches where necessary a vane type steering gear showing how to weight of the rudder and stock are carried and the arrangement that allow for wear down. (6)

B. State how the vanes described in (A) are secured and the method of sealing the edges. (5)

C. State how, if necessary, the steering gear is locked for rudder maintenance. (5)