DieselShip's Online Content Library

Q1. Describe a three-element feed water controller (i.e., regulator) measuring steam flow, drum level and feed water flow and explain what relationship is maintained between the three variables and how?

Q6. Sketch and describe a “fail safe steering gear” suitable for use on a tanker of more than 100,000 T dwt; Explain the sequence of events that take place when an oil leak takes place in one of the hydraulic pipe lines.

Q5. A. State why fixed pitch propellers have a poor efficiency when going astern.

B. With reference to controllable pitch propellers state:

i. Why is it preferable that the main servomotor be housed in the propeller hub rather than in the shafting forward of the propeller shaft?

ii. What regular maintenance and checks should be carried out to ensure maximum reliability of the gear at all times?

Q3. A. Describe the preparation necessary before the application (in dry dock) of sophisticated or approved long life coating to the underwater surface of the hull.

B. State the significance of the roughness profile.

C. List the different sophisticated coatings which are available.

Q1. A. Explain the ideal design requirements of a ships propeller; B. briefly describe the propeller maintenance that should be carried out to prevent the fuel being wasted.

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

Q7. With respect to the refrigeration system on board vessels, answer the following

a) Why are some TEVs fitted with an external equalizing connection?

b) What is the purpose of a back pressure valve. what will the effect if it leaks?

c)How does an electronic TEV function.

Q8. Discuss some of the factors which effect the shaft alignment of ships propulsion shafting. Suggest the most effective methods adopted for achieving the best possible alignment? (16)

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)