DieselShip's Online Content Library

Q1. (a) Explain the types of turbocharging in a marine diesel engine. (8)

(b) What are the reasons that may induce vibration on a main engine turbocharger? (8)

Q2. Explain how sluggish action of the suction and delivery valves reduces the volumetric efficiency of an air compressor. (16)

Q3. During your watch one of the main engine unit was indicating high exhaust temperature reading. Write a note to Chief Engineer explaining: (16)

(a) The probable cause of the abnormal running condition and how it was diagnosed

(b) List possible corrective actions

Q4. (a) What is the significance of an air cooler and why is the scavenge air temperature preferred to be maintained at 40°C? (8)

(b) What are the probable indications of a leaky air cooler as fitted to a two stroke main engine? (8)

Q5. The maritime decarbonization is a priority and there are various ships that are operating on alternative fuels. Discuss few potential alternate fuels by comparing their properties and list the advantages & disadvantages of at least three alternative fuel? (16)

Q6. Write short notes on:

(a) Main air starting valves (4)

(b) Exhaust valve rotator (4)

(c) Scavenge relief valve (4)

(d) Function of Labyrinth Seals in turbocharger (4)

Q7. Make a diagrammatic sketch of a jacket cooling water system as applied to a two stroke main engine. Indicate the temperatures and pressures in the system. Describe in particular the flow of water from entry to the engine to outlet from the engine and sketch the more important joints in the system. (16)

Q8. Write short notes on the following:

(a) Indicated Power (3)

(b) Specific fuel oil consumption (3)

(c) Brake power (3)

(d) Mechanical efficiency (3)

(e) Thermal efficiency (4)

Q9. Write Short notes on the following:

(a) Effect of worn out rings on oil consumption and blow past (5)

(b) Cylinder liner wears (6)

(c) Thermal loading of piston (5)