DieselShip's Online Content Library

Q1. With reference to Cylinder Liner lubrication of large two stroke engines. (16)

a) Outline the problems associated with improper lubrication of the liner and piston assembly of a large slow speed engine.

b) Describe and state the causes of cloverleafing and micro-seizure

c) List out the composition of a cylinder oil suitable for an engine operating on residual fuel.

--- Previously Asked As ---

Q5. a) Outline the problems associated with effective lubrication of the liner and piston assembly of a large slow speed engine. (6)

b) What are the causes of cloverleafing and micro seizure. (5)

c) Explain the composition of a cylinder oil suitable for an engine operating on residual fuel. (5)

2021/JAN/06

Q6. A. Outline the problems associated with effective lubrication of the liner and piston assembly of a large slow speed engine.

B. Describe the appearance and state the causes of each of the following:

i. Clover-leafing.               ii. Micro-seizure

C. Describe the composition of a cylinder oil suitable for an engine operating on residual fuel.

Q3. a) Describe with the aid of a sketch the construction of a single collar thrust bearing. (6)

b) Explain the principle on which it works. (5)

c) Explain how you would take the essential clearances and explain the significance of each of them. (5)

Q3. With regards to modern 4-stroke diesel engines, explain the following.

A. The function of protection ring installed on the upper part of liner.

B. The modification in fuel injection drive system compared to conventional 4-stroke engine.

C. Staggering of layout for multi hole nozzles.

D. Effect of swirl and squish during the combustion process and how swirl and squish is generated. (16)

Q4. How are large slow speed engines structured to withstand the following forces?

A. Forces due to combustion loads. (6)

B. Guide forces. (5)

C. Inertia forces. (5)

Q5. With reference to piston rings. (16)

A. State the reasons for breakage.

B. How maintenance and engine operation could minimize breakage?

C. Explain the possible consequences with respect to performance and safety of operating the engine with broken or severely worn piston rings

PREVIOUSLY ASKED

Q4. With reference to Main engine piston rings:

(a) Analyze the causes of piston ring breakage.

(b) How maintenance and engine operation can minimize piston ring breakage.

(c) Explain the possible consequences with respect to performance and safety of operating the engine with broken or severely worn piston rings

Q6. A. Explain how static and dynamic imbalance of crankshafts can be overcome. (5)

B. Discuss the methods employed to obtain primary, reciprocating balance in an engine and explain why they are not completely successful. (5)

C. Describe engine additions which may be fitted to overcome problems resulting from primary or secondary imbalance. (6)

Q7. (a) Cast iron welding is a challenging task, give reasons. (8)

(b) What alternative repair methods were employed by engine makers on a cast iron casing of an engine? (8)

Q8. With reference to large, fabricated bed plates explain:

A. With reason, why longitudinal strength and rigidity is important despite the contributions made by ship’s structure. (8)

B. With sketches show how the combustions loads imposed on piston and cylinder heads are transmitted to and absorbed by bed plates. (8)

Q9. a) Sketch and explain a fuel injection pump capable of variable injection timing. (10)

b) Explain how the fuel injection pump sketched in part (a) changes the timing and quantity of fuel injection. (6)