DieselShip's Online Content Library

Q5. a) Outline the problems associated with effective lubrication of the liner and piston assembly of a large slow speed engine. (6)

b) What are the causes of cloverleafing and micro seizure. (5)

c) Explain the composition of a cylinder oil suitable for an engine operating on residual fuel. (5)

Q4. With respect to piston cooling in large two stroke marine engines;

A. Briefly discuss the relative advantages and disadvantages of oil and water for piston cooling.

B. Sketch a piston for a large two-stroke crosshead engines indicating the coolant flow.

C. State the causes of piston cracking and burning and how it can be avoided.

Q5. Give a list of the properties or tests by which distillate and blended fuels may be specified or decisions be made on their fitness for use. Name the properties or constituents that may be found in a blended fuel having a high viscosity and high carbon content. Explain how they may cause problems in engine operation

Q9.  A report on the analysis of the main crosshead engine crankcase lubricating oil indicates the following contaminants or property changes. In EACH of the following cases give reasons for the possible causes of the contamination or property change, explaining how the actual cause would be detected; .

A. The presence of fresh water; B. White metal fragments; C. Reduced alkalinity reserve; D. Reduced anti oxidation reserve.

Q2. a) Explain the term fuel ignition quality and indicate how a fuel’s chemical structure  Influences its value
b) State, with reasons, the possible consequences of operating an engine on a fuel with a lower ignition quality than that for which it is timed.
c) (i) Explain how an engine might be adjusted to burn fuel of different ignition quality.
(ii) State what checks can be carried out in order to determine that the engine is operating correctly.

Q3. Describe the developments that have taken place in the design of bearings of slow speed marine diesel engines, including geometry and material, focusing on the reasons for such changes.

Q2. Periodical Lubricating Oil Analysis, its correct interpretation and corrective measures are of critical significance for the maintenance of marine machineries. With reference to the modern analysis techniques employed for the condition of L.O, discuss the following:

A) Elemental (Spectrometric) Analysis

B) Fourier Transform Infrared (FTIR) Spectroscopy

C) Particle Count

D) Base Number Vs Acid Number

Q9. Describe the developments that have taken place in the design of bearings of slow speed marine diesel engines, focusing on the reasons for such changes. (16)