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Q8. How are large slow speed engines structured to withstand the following forces?

A. Forces due to combustion load;

B. Guide forces;

C. Inertia forces.

Q9. (a) Describe how it is determined whether a crankshaft was twisted during a major “smash up” in a main engine. (4)

(b) Explain where twisting is most likely to occur. (4)

(c) Specify with reasons the degree of twisting that might be accommodated without correction (4)

(d) Explain briefly what adjustments and precautions should be instituted when putting an engine with a twisted crankshaft back into service. (4)

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. What is a “Cam"? Explain its function. With reference to its application in diesel engines

Discuss the requirement and the type of cam used in

a) Fuel Pump

b) Indicator drive

c) Inlet Valve

d) Exhaust Valve

e) Starting air distributor. (16)

Q3. Recent experience has shown persistence damage occurring on seating faces of main engine exhaust valve, which is not confined to any particular unit.

(a) State with reason the possible causes. (6)

(b) State the short-term action to be taken in order to minimize engine operational problem. (5)

(c) State with reason how future incident of this nature could be minimized. (5)

Q8. (a) With a aid of a sketch briefly describe the important structural parts of 2-Stroke main Engine? How are different structural parts held together? (10)

(b) What is the function of Cross Head Guides? (6)

Q3. Discuss critically the following alternative types of main propelling machinery for installation in a proposed new ship - A. 2 stroke single acting cross head type slow speed engine; B. 4 stroke single–acting with reverses / reduction gear.

Q9. (a) Describe what would be the indications of crank case explosion in main engine. (4)

(b) Describe actions to be taken, if there is crank case explosion in main engine. (8)

(c) Describe means of prevention of crank case explosion. (4)

Q1. Describe the procedure in lining up an engine bedplate, main bearings, gear box, thrust block, propeller shafting and tail-end shaft, assuming this to be a new ship.

Q7. (a) Sketch a section through the bedplate and A frame of a large slow speed engine, identifying parts, method of construction and materials (10)

(b) Explain the function of the tie bolts and how after an alignment problem, these would be tightened (6)

Q9. (a) If soon after joining as a second engineer on a motor vessel, you observed that number of holding down bolts are slack and fretting has occurred around slack holding down bolts. Describe what actions do you take. (8)

(b) Explain the correct procedure for checking the holding down bolts tightness? (8)

Q8. (a) (i) Describe with the aid of a sketch, a main engine exhaust valve which is hydraulically operated (8)

(ii) Explain the operation of this valve (4)

(b) State the materials used for the seat and valve described in (a) (4)