EKG-Apr-21(Mum)

 Q1. You have recently joined a vessel as Second Engineer Officer. For the past several voyages it has been the practice on board to dispense with the use of the exhaust gas boiler and leave it to run dry. As part of an overall economy, the drive company has requested you to re-commission the boiler. Write a letter to the Superintendent Engineer stating how the boiler was brought online and the safety valves adjusted.

Q2. With reference to windlass & deck machinery:

(a) Describe the principle of coil-operated brake suitable for winches and other deck machinery. 

(b) Explain with suitable sketches how the windlass is relieved of strain when riding at anchor.

Q3.  How the ingress of seawater is prevented in an oil-lubricated stern bearing system. Should the system fail, describe the corrective action possible whilst the vessel is afloat? State the reasons for fitting two stern bearing oil header tanks in some cases?

Q4.With reference to reciprocating air, compressors explain why; 

A. Clearance volume is critical to efficiency; 

B. Spring-loaded plate valves are invariably used; 

C. Compression is accomplished in apparently unequal stages; 

D. Inter cooling is used between stages.

Q5. With respect to refrigeration gases used on-board vessels, answer the following: 

A. Explain the Ozone Depleting Potential (ODP) and Global warming potential (GWP) of conventional refrigerant gases.

B. Name the alternate refrigerant gases available and being used onboard.

C. What steps are taken to minimize the release of refrigerant gases from the plant during normal operation and maintenance activities?

Q6. With respect to tankers describe: 

A. How a pump room and cargo tanks are ventilated? 

B. The main problem of carrying liquefied natural gas. 

C. How the boil-off from liquefied natural gas is handled?

Q7. A. Explain Creep; Brinelling; Fretting; Fretting corrosion; B. State, with reasons, where these may occur in ship propulsion System.

Q8.Compare the destructive testing done on engineering materials with non-destructive testing done on engineering components. Briefly describe one destructive test and two non-destructive tests to illustrate your answer

Q9. Reverse osmosis is the modern alternative for shipboard production of drinking water.

A. Describe using simple diagrams if necessary, the principle of reverse osmosis.
B. Sketch a line diagram showing a single pass system for producing fresh water from seawater and Describe such a system.