EKG-JAN-20

Q1. Sketch and describe the operation of four ram electro-hydraulic steering gear system. Indicate and explain the valve position for the operation of the system when one pump is isolated and unit is operating on two rams only.

Q2. With reference to Flue gas Inert gas system:
A. Sketch and describe using a line diagram showing a typical 'Inert Gas System' used for inerting the cargo tanks of oil tankers, labelling the component parts.
B. State what oxygen content you would expect in the flue gases if good combustion is achieved.

Q3. 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.

Q4. With respect to properties of fuel oil, explain the significance of the following terms;
(a) Calculated Carbon Aromaticity Inbox (CCAI).
(b) Open flash point and Closed flash point.
(c) The importance of Sodium to Vanadium Ratio.
(d) Octane Number.

Q5. Describe the importance of maintaining the quality of lube oil in maintaining the proper health of marine diesel engines highlighting the role of (a) Automatic back flushing filters. (b) Lube oil separators (c) Magnetic filters (d) Visual Inspection (e) Periodic laboratory tests.

Q6. 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?

Q7. Discuss the causes of corrosion and the means by which corrosion of the following may be limited by manufacturers and ship’s personnel respectively:
A. Internal and External surfaces of auxiliary steam lines;
B. External surfaces of auxiliary boilers;
C. Water boxes of seawater coolers and condensers;
D. Main sea water inlet pipes.

Q8. 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.

Q9. 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.