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Q12. With reference to drainage from a ship’s external structure, explain EACH of the following :

(a) why scuppers are located in close proximity to the superstructure, whereas freeing ports are generally located at open areas of the weather deck;  (3)

(b) why it essential that scuppers and freeing ports are operational at all times ;  (4)

(c) why oil tankers have handrails on the main cargo deck other than for reasons of personnel safety. (3)

With reference to cargo hatch covers on large container ships:

(a) describe how they are tested for weathertightness; (2)

(b) explain how the weight of the hatch and containers is transferred to the ship's structure whilst allowing for deflections of the hull in a seaway;(3)

(c) describe, with the aid of a sketch, the type and location of damage that can occur due to wear of the hatch supporting arrangements. (5)

Q14. During sea trials, extensive noise measurements are taken in accordance with the Code of Practice for Noise Levels in Ships.

(a) State and explain the unit of sound measurement. (2)

(b) State the noise level above which personnel are required to wear ear protection. (1)

(c) Explain how a ship's crew may be made aware of the hazards posed by exposure to excessive noise (2)

(d) Explain how the noise levels can be reduced in the design of EACH of the following:

(i) diesel generators;(3)

(ii) ventilation fans and trunkings. (2)