DieselShip's Online Content Library

Q1. With reference to electric arc welding:

(a) Draw a labelled sectional sketch of a satisfactory butt weld. (4)

(b) Briefly define the following defects that may occur and how they may have been caused: (12)

(i) Under cut

(ii) Splatter

(iii) Inclusion

(iv) Blow hole

(v) Incomplete root penetration

(vi) Lack of fusion

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 laces 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) DONE

Q5. Sketch and explain the construction of a feed Check Valve. Why is it known as double shut off arrangement. (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. (a) Sketch a screw displacement pump and explain its operation (10)

(b) State the factors which affect its efficiency. (6)

Q7) With reference to main air reservoirs:

(a) Explain with 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)

Q1) (a) Using a line diagram, show the arrangement of ‘emergency bilge suction’ for a general cargo ship (8)

(b) State the purpose of ‘bilge injection valve’ and to which pump or pumps it is connected. Give reasons. (4)

(c) State requirements with respect to the dimensions of the bilge injection valve and the main sea suction valve on the sea chest. (4)

Q2) (a) What are the advantages and disadvantages of the single-coil type and the straight-tube type of inter-cooler for air compressor? (10)

(b) Why are the tubes and coils generally made of copper? (6)

Q3) (a) With the aid of a sketch describe the working of a shell and tube type freshwater generator. (10)

(b) What are the probable causes of fluctuating and unsteady vacuum in such an evaporator and what would be the consequence of such an unsteady vacuum? (6)

Q4) (a) Make a detailed sketch of a Ship's domestic refrigeration system. (8)

(b) Give a full description of such a Refrigeration System, explaining the purpose of the relevant control and safety devices. (8)

Q5) (a) In the context of auxiliary boiler. Explain what do you understand by the term ‘foaming’. List the measures you would consider to prevent it? Is it different from ‘priming’ in the auxiliary boiler context? (6)

(b) Explain any one of the following with a sketch. (6)

(i) Composite boiler

(ii) Exhaust gas economiser

(c) What is the significance of ‘de-aeration’ of the boiler water? How is it achieved and what are the effects if ignored? (4)

Q6) Write short notes to explain the following fittings/devices used in engine room, and their applications: (16)

(a) Low sea suction

(b) Fretting corrosion

(c) Caustic embrittlement

(d) Air starting motor

Q7) (a) Sketch a four-ram steering gear arrangement capable of 100% redundancy. (8)

(b) Describe the operation of the arrangement sketched in (a). (8)

Q8) a) Sketch a line diagram showing a typical “Inert Gas System used for inerting the cargo tanks of oil tankers, labelling the components parts. (6)

b) Describe the system. (8)

c) State what oxygen content you would expect in the flue gases if good combustion achieved (2)

Q9) (a) Sketch a nozzle/flapper device used for the generation of a pneumatic signal, labelling the component parts (10)

(b) Describe the operation of the device in (a) above (6)