DieselShip's Online Content Library

Q1. During a loaded sea passage an unusual noise followed by excessive vibrations were experienced in the engine room of your vessel while she was underway. Vessel is fitted with a four-bladed propeller directly coupled to a 2 stroke Diesel engine. Engine room is located aft. After preliminary investigation and from the engine parameters, you have come to the conclusion that propeller has sustained damage. Write a letter to your company reporting this incidence and justification for your conclusion suggesting future course of action.

Q2. Draw a line diagram of an accommodation air conditioning plant labelling the principle items and showing the direction of airflow. State how: A. Accommodation air temperature is controlled; B. Humidity is controlled within prescribed comfort limits; C. such an installation can contribute to the efficiency if ship’s main plant

Q3. A. Sketch in diagrammatic form, a refrigeration unit operating on the vapour compression system. B. Describe how it operates and how adjustments can be made to its operating temperature. C. What effect will the following have on its operation i. high ambient temperature. ii. Gradual loss of gas. iii. Dirty heat exchanger

Q4. During routine soundings, it is found that leakage into a cofferdam is occurring from an adjacent deep cargo oil tank. As Second Engineer state the procedure for directing safe entry by the engine room staff to ascertain the cause of the leakage. If the leakage persists, discuss EACH of the following options as a possible remedy: i) Leave the cofferdam to flood with oil (ii) Flood the cofferdam with sea water (iii) Seal the Cofferdam and pressurize with air (iv) Pump the leakage to bunker tanks.

Q1. Discuss, with reference to the superheater outlet temperature of the main boiler operating at a constant load, the following statements:

a) An increase in excess air will tend to cause a decrease in superheater outlet temperature due to the cooling effect of more air being introduced.

b) A decrease in economizer inlet temperature will tend to cause a decrease in super heater outlet temperature due to the cooling effect of more water being introduced.

c) Badly fouled generating tube banks will cause an increase in the super heater outlet temperature.

d) Excessive amounts of total dissolved solids in the boiler water will cause variations in the super heater outlet temperature

Q6. With reference to hydraulic system for deck machinery identify: A. The types of contamination likely to be found in hydraulic systems for deck machinery; B. The sources of such impurities; C. Means used to prevent problems with contamination; D. Possible effects of the oil contamination on the system.

Q2. Sketch a high-lift safety-valve lid and seat detailing their special features. Describe how such a valve is overhauled and any clearance that should be measured and noted. (16)

Q3. A. Sketch and describe TWO methods that employ manometric means for measuring tank contents. (6)

B. State what corrections are made to the readings obtained by the methods described in (A) in order to gauge the mass contents? (5)

C. Explain how bunkering requirements may be estimated when no records of main engine fuel consumption are available on board. (5)

Q4. A. Describe with the aid of sketches where necessary a vane type steering gear showing how to weight of the rudder and stock are carried and the arrangement that allow for wear down;

B. State how the vanes described in (A) are secured and the method of sealing the edges;

C. State how, if necessary, the steering gear is locked for rudder maintenance.