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Q1. With reference to main engine tie rod explain.

A. Function (3)

B. Effect on main engine in case slack (3)

C. Identifying slackness (3)

D. Material (3)

E. Tightening procedure. (4)

Q2. (a) State, with reasons, the properties required for a cylinder lubricant for a main engine operating on HFO. (8)

(b) Describe, with the aid of a sketches, an electronically controlled cylinder lubrication system, stating how the timing and quantity of cylinder lubricant is regulated and set. (8)

Q3. (a) Define the term Torsional Vibration with respect to an engine crankshaft, stating the effect that high levels can have on an engine crankshaft. (6)

(b) Explain how engine deterioration influences the risk of Torsional Vibration, stating what can be done to minimise that risk. (5)

(c) Explain TWO possible reasons for the activation of a Torsional Vibration alarm after an engine has been started if there had been no previous history of such an alarm and if no maintenance had been undertaken on the engine whilst it was stopped. (5)

Q4. With reference to LNG diesel engine installations:

(a) Describe, with the aid of a sketch, a Gas Valve Unit, explaining its purpose and indicating where it is located in the gas train. (6)

(b) Explain why ventilation and inert gas systems must be installed with the engine fuel gas system. (5)

(c) State why pilot injection must be provided when burning fuel gas, explaining how a pilot injection system works (5)

Q5. a) Identify the factor, which could be responsible for initiation and propagation of explosions in air starting systems. (4)

b) Explain how the possibility of an explosion in an air start system is minimized.  (4)

c) Describe the devices required for air start systems, which are intended to dissipate the energy of an explosion. (4)

d) Suggest why one type of safety addition, although appearing to operate correctly, may not prevent a server air start line explosion and loss of life. (4)

Q5. Give a list of the properties or tests by which distillate and blended fuels may be specified or decisions be made on their fitness for use. Name the properties or constituents that may be found in a blended fuel having a high viscosity and high carbon content. Explain how they may cause problems in engine operation

Q7. Evaluate the influence of the following factors upon cylinder and piston ring wear rates. (16)

A. Position of rings in relation to piston crown.

B. Spread and proximity of coolant passages from liner wall.

C. Flow rate and specific heat of coolant.

D. Chromium plating of ring faces.

Q8. a) (i) Describe with the aid of a sketch, one section of a large slow speed engine crankshaft which has been assembled by shrinkage of webs onto journal pins. (4)

(ii) Explain how a five-degree twist might be caused to a shaft assembled by shrinkage. (4)

b) State the possible effects of a five - degree twist in the crankshaft assembly and draw conclusions as to whether the engine should be operated and any adjustments that may be necessary for continued operation. Assume that the incident has occurred at a port with no repair facilities. (8)

Q9. (a) Why is the axial clearance of a main thrust bearing an important dimension? (6)

(b) How is this clearance measured? (6)

(c) Describe how the thrust pads are removed for inspection and state what you would look for in particular. (4)