EKG-Apr-21

Q1. With regard to care of lubricating oils on board answer the following –A. What is microbial degradation of lubricating oil and how is it prevented? What methods are employed to ensure correct sampling for shore based testing?

B. What action will you take If the testing results show abnormal values of water content and TBN for crank case lube oil of a slow speed main engine?

Q2. State with reasons, how cracking in EACH of the following location is caused, rectified and avoided a. “A”-frame. b. Bedplate longitudinal girder. c. Bed plate transverse girder.

Q3. Damage has occurred to the main engine exhaust valves and the fuel supplied at a particular port is suspected. The owner’s case, however, in the subsequent dispute may be weak because the fuel was ordered specifying only type and viscosity. A. Apart from fuel specification, describe how you, as Second Engineer, should have assisted the owners’ case when receiving the suspect fuel. B. Describe the ISO fuel standard that is to be used when ordering bunker fuel. C. Explain how the correct fuel standard is selected. D. Suggest, with reasons, why particular mention should be made of certain elements that might not be included in the fuel standard.

Q4. 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.

Q5. A. Explain Creep; Brinelling; Fretting; Fretting corrosion; B. State, with reasons, where these may occur in ship propulsion System.

Q6. Sketch and describe a “fail safe steering gear” suitable for use on a tanker of more than 1,00,000 T DWT; Explain the sequence of events that take place when an oil leak takes place in one of the hydraulic pipe lines.

Q7. Sketch a sealing arrangement for an oil lubricated stern tube. Identify the common forms of seal failure; State how oil loss due to seal failure can be restricted whilst on passage? What is the material used for sealing rings and propeller shaft liner?

Q8. With Respect to Container Ship: -

A. Sketch a ship’s indirect refrigeration system arranged for cooling containers stowed in stacks in the hold;

B. Describe the refrigeration system sketched in (A); compared with containers with their own refrigeration self-contained units.

Q9. With reference to vacuum sewage system: 

(i)   Sketch & Describe a Vacuum Sewage System.
(ii)  State the advantages of Vacuum Sewage System.
(iii) State the different causes of dropping vacuum.