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Q4. With reference to marine diesel engines:

(a) State the purpose of a camshaft. (2)

(b) State TWO methods of driving a camshaft on a large marine diesel engine. (4)

(c) State the speed of the camshaft relative to the crankshaft on:

(i) A four-stroke engine: (2)

(ii) A two-stroke engine. (2)

(d) Sketch a fuel cam for a unidirectional diesel engine indicating EACH of the following:

(i) Point of injection. (2)

(ii) Peak. (2)

(iii) Slow return. (2)

Q4. With reference to the reversing of an engine:

(a) Describe THREE methods by which it may be achieved (12)

(b) Explain what is meant by lost motion (4)

Q1. With respect to Main Propulsion Engines, state the immediate action to be taken as Engineer Officer of the watch in the event of EACH of the following, stating ONE reason why EACH action is necessary:

(a) Turbocharger repeatedly surging. (4)

(b) Air start manifold/branch pipe overheating local to one unit. (4)

(c) Low scavenge air temperature alarm. (4)

(d) Engine misfires, fuel rail pressure low alarm activates, booster pump pressure high (4)

Q2. (a) Sketch a typical power indicator card for a slow speed marine diesel engine. (6)

(b) Explain how the card may be used to assess the power developed in the cylinder. (10)

Q1. With reference to scavenge fires:

(a) State FOUR possible contributing factors. (4)

(b) Explain how EACH factor mentioned in (a) contributes. (8)

(c) State FOUR indications. (4)

Q4. (a) Describe how the thrust of the propeller is transmitted to the hull of the ship. (4)

(b) Describe, with the aid of a sketch, how the surfaces, within the thrust block, transmitting the thrust are separated by the lubricating oil. (8)

(c) Explain the importance of the oil temperature within the thrust block (4)

Q3. (a) Answer the following:

(i) State why the simultaneous injection of fuel oil and starting air into a main engine cylinder is undesirable. (2)

(ii) Explain how simultaneous injection of fuel oil and starting air is prevented. (4)

(b) Answer the following:

(i) Explain how a leaking air start valve is detected while the engine is running. (4)

(ii) Describe the actions to be taken upon discovery of a leaking air start valve. (6)

Q3. (a) Draw a line diagram of a main lubricating oil system for a large two-stroke cross-head type diesel engine. Label all the principle components of the system. (16)

Q3. Describe the procedure to change the fuel supply system of the main propulsion engine from high viscosity fuel to low viscosity fuel such as diesel oil whilst on passage. (16)

Q1. With reference to shutting down a main propulsion diesel engine plant, after a voyage, explain EACH of the following:

(a) The conditions to be met for transferring from Bridge control to Engine Room Control just prior to shut down (8)

(b) FOUR precautions to be taken after shutdown, in order to ready the main engine for maintenance (8)

Q4. With reference to main diesel engine starting air lines:

(a) Describe the main cause of a starting air line explosion. (8)

(b) Explain how a leaking start air valve can be identified while the engine is running. (4)

(c) State four different safety devices which can be incorporated into the starting air line to limit the damage caused by an explosion. (4)

Q1. With reference to the operation of main propulsion engines, outline the importance of EACH of the following:

(a) Maintaining the temperature of the scavenge air above the dewpoint (4)

(b) Maintaining the fuel at the correct viscosity for injection (4)

(c) Regular on board testing of the lubricating oil (4)

(d) Ensuring rotation of exhaust valves (4)