DieselShip's Online Content Library

Q1. With reference to centrifugal pumps:

(a) (i) Sketch typical discharge characteristics showing variation of throughput as the

discharge head and speeds are altered; (4)

(ii) Explain why this characteristic profile is desirable; (4)

(b) Explain the relevance of discharge characteristic for the selection of an emergency

fire pump. (8)

Q2. (i) Discuss the use of non-metals onboard ships & name some of the common nonmetals used (4)

(ii) What are their areas of application on ships? (4)

(iii) Name the advantages & also the limitations in using non-ferrous materials (8)

Q7. With reference to electric arc welding:

a) Draw a labeled sectional sketch of a satisfactory butt weld. (5)

b) Briefly define the following defects that may occur and how they may have been caused (6)

i) Under cut

ii) Splatter

iii) Inclusion

iv) Blow hole

v) Incomplete root penetration

vi) Lack of fusion

c) Why is alternating current generally more popular then direct current for metal arc welding? (5)

Q9. i) Explain the term 'incinerator' and the function of incineration on board ships in order to prevent/ minimize contamination of marine environment. Draw a typical process flow diagram on incineration. How is incinerator ash disposed off. (16)

Q5. Explain how each of the following, conditions contribute to the satisfactory

performance of oil centrifuges (16)

(a) correct bowl speed

(b) cleanliness of bowl

(c) low rate of feed to bowl

(d) Contaminated oil allowed to stand for an appreciable time prior to centrifuging.

Q6. i) Sketch and describe a fuel system diagram for a 2 stroke Marine diesel engine from storage / service tank to fuel injectors.  Show the various components and fittings which are provided in the circuit. What is the purpose of mixing columns & autodeaerating valve? (16)

Q7. State the causes and remedial actions to be taken in case of the following occurring on an air compressor:

(a) Water mixed in the crankcase oil (4)

(b) LP safety valve blowing (4)

(c) Bursting disc rupture (4)

(d) Problems caused by detective piston rings (4)

Q8. (a) Describe the effects of freshwater feed on auxiliary boilers. (6)

(b) Describe the measures taken to reduce these effects. (4)

(c) Describe FIVE principle boiler water tests stating the reason for EACH. (6)

Q9. (i) Discuss 'on board testing' of lubricating oil. What are the salient points for which lube oil testing is necessary? (4)

(ii) Name the test which are normally carried out and reasons for same. (4)

(iii) Name instruments used for measuring ‘viscosity' and 'flash point' Explain their, working principle (8)