DieselShip's Online Content Library

Q7. With respect to large two stroke crosshead main engines;

A. Sketch and describe a crosshead designed to prevent or minimize bearing edge loading.

B. State how the arrangement describe a achieves its purpose.

C. What would be an acceptable range of bearing clearance for the top end bearing and bottom end bearings of a large two-stroke marine diesel engine.

Q2. As a second engineer, you are required to offer for survey, to a Classification Society, a crosshead of the engine following an unscheduled repair due to bearing failure.

A. Outline the information you would be required to provide prior to the survey. (6)

B. Briefly describe the survey procedure likely to be adopted stating with reasons the areas which should receive close attention. (5)

C. State with reasons what information would be requested by the surveyor and /or the operation required to be observed after re-assembly of the crosshead. (5)

Q6. (a) Describe, with the aid of sketches, the procedure for cutting out and "hanging-up" an engine cylinder of a two-stroke crosshead engine in the event of complete failure of the crosshead pin such that the crosshead pin cannot be operated and no replacement is immediately available. (12)

(b) State, with reasons, the factors which may inhibit starting and limit the operating speed of the engine with a cylinder cut out. (4)

Q9. a) State the reason for fitting crosshead guides to engines and explain why ‘ahead’ and ‘astern’ faces are required with uni-directional engines.

b) Describe how crosshead guide clearance is checked and adjusted.

c) List reasons for limiting such crosshead clearance.