DieselShip's Online Content Library

Q1. (a) Describe the properties of EACH of the following alloys used in marine engineering,

giving a practical example for which, EACH are suited:

(i) cupro-nickel; (2)              (ii) white metal; (2)              (iii) titanium. (2)

(b) Discuss the merits of EACH of the following alloys for use in the casting of large propellers:

(i) nickel aluminium bronze; (2)                (ii) stainless steel. (2)

Q2. (a) State the factors in the storage of Manual Metal Are welding electrodes which will assist in producing good quality welds. (2)

(b) Explain the importance of edge preparation before welding. (2)

(c) Sketch THREE electric arc welding defects, stating the cause of EACH. (6)

Q2. (a) Describe, with the aid of a sketch, the principle of operation of a modern shaft torsion meter. (8)

(b) Explain why it is important in terms of hull efficiency to measure and compare shaft torque and speed. (2)

Q4. (a) Sketch a hydraulic type of shaft coupling bolt. (4)

(b) State the advantages of the arrangement in part (a) compared to conventional bolts. (3)

(c) State THREE operational Factors that may induce high stress in shaft coupling bolts.(3)

Q4. With reference to centrifugal pumps:

(a) Explain how the performance may be assessed without the need to dismantle the pump; (3)

(b) state the effects of misalignment between the driving motor and the pump; (3)

(c) describe, with the aid of a sketch, how on a new replacement motor, alignment is checked and adjusted. (4)

Q6. (a) Sketch an oily water separator that compiles with current MARPOL regulations.

(b) Describe a monitoring system that ensures that the oil discharge content is below the recommended maximum and that logs and retains data. Also mention any other measures to ensure that illegal discharges are prohibited.

Q6. With reference to refrigeration systems:

(a) explain why undercooling of the refrigerant at the condenser outlet is desirable; (3)

(b) describe, with the aid of a sketch, how a heat exchanger could be incorporated in the circuit to enhance undercooling; (5)

(c) explain the possible consequences of the refrigerant having a dryness fraction at the compressor suction. (2)

Q8. With reference to tanks containing hydrocarbon liquids and vapours:

(a) Define EACH of the following terms:

(i) Explosive limits; (2)        (ii) vapour pressure; (2)      (iii) flash point. (2)

(b) Explain how the atmosphere in cargo tanks containing varying percentages of flammable gas can be maintained in a safe condition at all times. (4)