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Q4. A. State the laboratory tests that may be carried out on specimens of steel for ships’ plate giving reasons for the tests.

B. The basic compositions of two ships’ plates are given in Table below one is an example of modem practice whilst the other is a specification of a 1940’s tanker that split in two due to brittle fracture. Compare these two specifications critically and explain which of these two steels would be most resistant to brittle fracture

Q2. (a) Define the term Torsional Vibration with respect to an engine crankshaft, stating the effect that high levels can have on an engine crankshaft.

(b) Explain how engine deterioration influences the risk of Torsional Vibration, stating what can be done to minimise that risk.

(c) Explain possible reasons for the activation of a Torsional Vibration alarm after an engine has been started if there had been no previous history of such an alarm and if no maintenance had been undertaken on the engine whilst it was stopped.

Q2. Describe methods of static and dynamic balancing of an engine and describe what are first order, second order and higher order moments in engine.

Q9. With reference to machinery parts under cyclic loading, describe, with the aid of sketches, the propagation of even the smallest of cracks can lead to total component failure. (16)

Q4. Define the following types of non-destructive methods of testing:

a) Radiographic. (4)

b) Ultrasonic. (4)

c) Magnetic particle. (4)

d) Dye penetrant. (4)

Give their advantages and disadvantages.

Q6. Hydrogen damage is a general term used for mechanical damage of metal caused by the

presence of hydrogen, briefly discuss the different types of hydrogen damage and how these damages can be prevented?

a) Hydrogen blistering (4)

b) Hydrogen embrittlement (4)

c) Decarburization (4)

d) Hydrogen attack (4)

Q1. You have been appointed as Second Engineer to a new vessel that experiences severe aft end vibration. The problem is thought to emanate from the propeller. Describe the cause of vibration and suggest possible remedies including the selection of a new propeller with a different number of blades.

Q4. Briefly Discuss the effects of following on corrosion: (16)

a) Dissolved Oxygen

b) Hydrogen Ion concentration

c) Temperature

d) Velocity

Q2. Cast iron is most widely used metal after steel in Marine Engineering. Most cast irons consist of graphite in steel like matrix. Discuss the variation of properties that may arise with reference to pearlitic grey cast iron and spherical grey cast iron. Describe briefly the treatment necessary to produce these two types of Irons.

Q7. What are the major types of stainless steels used on merchant ships? Briefly explain each type. Which grades would you recommended for use in sea water environment? Why?

Q6. a) Discuss three metallurgical/processing techniques that are employed to enhance the creep resistance of metal alloys. (8)

(b) Define creep and specify the conditions under which it occurs? (8)

Q4. (a) Discuss the principle, different methodologies, advantages, limitations & applications of Ultrasonic testing.

(b) Explain how Magnetic Particle Testing (MPT) is carried out in different ways? State its advantages, limitations and applications