DieselShip's Online Content Library

Q1. The main requirements which a fuel injection system must fulfil are (16)

(a) Accurate metering of small amount of fuel oil

(b) Control of quality of fuel injection

(c) Proper timing of the fuel injection

(d) Selective distribution of the fuel in the combustion space

State whether each one of the points made above are true or false with reasons.

Q2. The cylinder liner of one of the unit is cracked inspite of the engine having logged only 300 hours since last overhaul. Make a report of what you feel could be the cause of this mishap (16)

Q3. (a) Briefly explain the construction and functions of a bedplate in a slow speed marine diesel engine? (8)

(b) How is the bedplate fastened to the hull structure? (4)

(c) What is the function of the tie-rod in a slow speed 2-stroke engine? (4)

Q1. An auxiliary engine under load continuously fluctuates even with a steady load. The fault you diagnose could be owing to: (16)

(a) The quality of fuel

(b) The quality of servicing of the governor in the last port

(c) The supply of charge air

(d) The overhaul of fuel injectors done in the last decarbonization Give a brief explanation as to why each of the above mentioned points either could be true or cannot at all be the reasons for such a fluctuation.

Q5. (a) Why exhaust outlet of marine diesel engine turbocharger is lower than inlet temperature? (6)

(b) Why do we need an air cooler and why is the scavenge air temperature maintained at 40°C? (10)

Q8. (a) (i) Describe with the aid of a sketch, a main engine exhaust valve which is hydraulically operated (8)

(ii) Explain the operation of this valve (4)

(b) State the materials used for the seat and valve described in (a) (4)

Q7. (a) Why do you need an 'over-speed' trip despite a governor being fitted to a marine diesel engine? (8)

(b) With respect to an auxiliary engine governor, what is the significance of: (8)

(i) The Load limit knob

(ii) The compensation

Q8. (a) Explain briefly how the different moving parts of a main engine are subjected to various stresses. (8)

(b) Name the stresses and justify by stating how they originate. (8)

Q1. (a) Describe the procedure for taking crankshaft deflection of Auxiliary Engine, explaining all precautions that must be observed (8)

(b) Explain what deflection readings actually mean and suggest the action which must be taken should readings be outside values recommended by the engine manufacturer. (8)