EKG-Sep-21

Q1. 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.

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. With reference to radial lip seals for propulsion shafting : (a) Sketch and describe an outboard seal arrangement as fitted to an oil lubricating stern tube; (b) Explain, with reasons, the possible actions that should be taken in the event of loss of oil from the heater tank.

Q4. With reference to fuel oil viscosity: (a) Explain why correct fuel oil viscosity is necessary (b) Describe TWO methods for the measurements of viscosity that are suitable for the inclusion into a pneumatic or electronic control system; (c) State, with reasons, a control action for a viscosity controller.

Q5. A. Sketch a line diagram showing the layout components of a hydraulic system with a variable delivery, Pressure compensated pump and accumulator, suitable for the operation of deck machinery. B. Describe the operation of the system sketched in (a).

Q6. With reference to the fuel standards, ISO-8217-2017 discuss the amendments made as compared to its previous edition. Explain the significance of the following: 

(a) Pour point, cloud point and cold filter plugging point. 
(b) Cat fines 
(c) Fatty Acid methyl Easter 
(d) Dissolved H2S in fuel.

Q7. With respect to Energy-efficient running of ships; 

(a) Sketch and explain the optimization of propeller hull interface flow devices and improvement of propulsion efficiency. 

(b) sketch and explain the optimization of Auxiliary machinery using VFDs.

Q8. Sketch and describe the operation of four rams electro-hydraulic steering gear systems. Indicate and explain the valve position for the operation of the system when one pump is isolated and the unit is operating on two rams only.

Q9. Cast iron is the 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.