EKG-Feb-21

Q1. With respect to the properties of fuel oil, explain the significance of the following terms;

(a) Calculated Carbon Aromaticity Inbox (CCAI).
(b) Open flash point and Closed flashpoint.
(c) The importance of Sodium to Vanadium Ratio.
(d) Octane Number.

Q2. A. With reference to fatigue of engineering components;

A. Explain the influence of stress level at a cyclical frequency on expected operating life.;
B. Explain the influence of material defects on the safe operating life of engineering components;
C. State the factors which influence the possibility of fatigue cracking of an auxiliary boiler feed water pump shaft and explain how the risk of such cracking can be minimized.

Q3. 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 pipelines.

Q4. Sketch and describe a boiler water level controller of the float operated type. State the reasons for having this mechanism on the boiler and using this controller and boiler for analogy explains the following terms: A. Detecting element; B. Servo motor; C. Desired Value

Q5. You were asked to join a ship as a second engineer. During the briefing, you were informed about frequent boiler uptake fires happening on board. Prepare a plan for to reduce boiler uptake fires. How will you monitor the progress of your plan and what instructions you will issue to the watchkeepers?

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. With regards to main transmission shaft flange coupling arrangements:

A. Sketch a hollow type coupling bolt and the hydraulic head/nut and loading rod which are used to fit it;
B. Describe how the bolt is fitted;
C. State the advantage of the hollow coupling bolt as compared to the traditional type of coupling bolt.

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. A new vessel exhibits severe aft end vibration A. As a Second Engineer Officer, outline a procedure to investigate and identify the source of vibration B. Suggest possible remedies to obviate/reduce aft end vibration.