EKM-Nov-2020

Q1. Sketch and describe an overview Of the electronic controlled camshaft-less engine with respect to the following operations: a. Fuel Injection system. b. Exhaust valve actuator system. c. Cylinder lubrication system.

Q2. With reference to turbocharger bearings: A. Discuss the relative advantages and disadvantages of white metal sleeve and ball race bearings for turbocharger rotor support. B. State with reasons how axial location of the rotor is achieved. C. Explain how the bearing are kept cool in service. D. Indicate how the bearings are sealed from the atmosphere and exhaust gas.

Q3.As second engineer you have been requested to obtain a set of indicator card (diagram) from the large slow speed engine of a recently purchased second hand ship. 

A. Describe your initial checks and preparations; 

B. State with reason the types of card you would consider necessary and explain the procedure for obtaining these; 

C. State in order of importance the additional information required with the card; D. State your procedure for analysis of the cards and obtaining cylinder powers.

Q4. Explain the term “cascade control’ and sketch such a system suitable for use with a main engine jacket cooling water system. Show the variation of pressure and temperature at major points of the system.

Q5. Sketch and show all parts of a two-stroke engine stuffing box. Describe the procedure of overhauling two stroke engine stuffing box, without removing piston. All safety precautions to be mentioned proper tools used for overhaul mentioned.

Q6. A. Sketch and describe Main engine starting air distributor. 

B. List the safety devices and interlocks incorporated in main engine air starting system and state the purpose of each.

Q7. With reference to crankshafts, explain EACH of the following: 

A. The cause and effects of torsional vibration; 

B. The term critical speed indicating why it can be a problem; 

C. The term fatigue cracking and state, with reasons, TWO factors of crankshaft operation which have greatest influence on the likelihood of fatigue cracking. 

D. How a torsional vibration damper can reduce the effects of torsional vibration

Q8. With reference to mechanical/hydraulic governors: A. Why flyweights are driven at a higher rotational speed than the engine; B. How dead band effects are reduced; C. How hunting is reduced; D. How the output torque is increased.

Q9. A. State the reasons for the progressive slackness of an engine camshaft drive chain in service; B. State the effect chain stretch has on engine timing and performance; C. Describe how correct timing is restored when chain stretch becomes excessive.