DieselShip's Online Content Library

Q1. a) How does heat treatment affect the properties of metals? Discuss common heat treatment processes. (6)

b) Describe the factors that influence the corrosion of metals and methods to prevent corrosion. (6)

c) What are the factors that affect the mechanical properties of materials, such as hardness, toughness, and ductility? (4)

Q2. Make a diagrammatic sketch of an exhaust gas boiler. Describe its construction and explain how it is maintained in an efficient condition. (16)

Q3. Explain the following briefly with reference to a domestic refrigeration system on board a ship. (16)

(a) Ingress of air into the freon system.

(b) Loss of refrigerant from a condenser.

(c) Water in the freon system.

(d) Icing of condenser external surface.

Q4. (a) Sketch a water-tight door and frame showing manner of attachment to bulkhead and the additional reinforcement carried by the bulkhead to compensate for the aperture (8)

(b) Explain how watertightness of the door and frame mating surface is ensured with an hydrostatic pressure tending to force the faces apart. (4)

(c) Describe the means of remote closing operation of the door and state how many closing stations there are and their position. (4)

Q5. 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 & autode-aerating valve? (16)

Q6. With reference to auxiliary boiler water impurity define the effects of the following salts: (16)

(a) Calcium carbonate,

(b) Sodium chloride,

(c) Magnesium chloride,

(d) Calcium sulphate

Explain how the quantity of each is determined and controlled.

Q7. Write short notes on the following:

(a) Ultrasonic testing (8)

(b) Shaft earthing device (8)

Q8. i) Define ‘centrifugal pump’ and where it is used on ships? Using a simple line diagram show a circuit which include a centrifugal pump. Explain the meaning of ‘suction lift’. (6)

ii) Sketch and describe the construction of a centrifugal pump, labelling its parts. What is a ‘lantern ring’ and why is it fitted? (10)

Q9) With reference to main air reservoirs:

(a) Give a line sketch the manner in which mountings are attached to the shell (6)

(b) Explain why regular internal inspection is advisable (4)

(c) What inspection and maintenance will you carry out on an air reservoir? (6)

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Q9) (a) Explain with a line sketch the manner in which mountings are attached to the shell (6)

(b) Explain why regular internal inspection is advisable (4)

(c) What are the areas that need particular attention during the inspection and survey of a main air reservoir. (6)