Main Propulsion Shaft
With reference to main propulsion shaft hydraulic sleeve type couplings:
(a) describe, with the aid of a sketch, the removal procedure;(7)
(b) state how it is determined, during reassembly, that the push fit is complete.(3)
1.Quiz. Study Notes
With reference to main propulsion shaft hydraulic sleeve type couplings:
(a) describe, with the aid of a sketch, the tightening procedure;(7)
(b) state how it is determined that the push fit is complete.(3)
Question 7.
Some sketches are very poor and show little understanding of the mode of operation of the coupling, this is then reflected in the answer. Many think that the separation oil is only for lubrication.
2.Quiz. Study Notes
With reference to comparing modern water lubricated stern tube bearings with those that are oil lubricated:
(a) state THREE advantages; (3)
(b) state THREE disadvantages, explaining how EACH may be overcome.(7)
3.Quiz. Study Notes
Whilst a single screw vessel is on passage it is noticed that an intermediate shaft bearing is running hot.
(a) State FIVE possible causes.(5)
(b) Explain the procedure that should be followed in order to reach port for further investigation if there were no further causes.(5)
4.Quiz. Study Notes
With reference to propulsion shaft intermediate bearings of the plain bearing type, explain EACH of the following:
(a) how change of alignment due to vessel condition is allowed for;(2)
(b) why the shaft must be able to move longitudinally;(4)
(c) why the aftmost bearing requires a complete bush but other bearings may have the bush only in the lower half.(4)
5.Quiz. Study Notes
With reference to stern bearings, state the advantages and disadvantages of using EACH of the following:
(a) white metal;(5)
(b) plastic.(5)
6.Quiz. Study Notes
(a) Sketch a flexible coupling that could be used for a main propulsion drive.(7)
(b) State THREE reasons for using a flexible coupling in propulsion drives.(3)
7.Quiz. Study Notes
With reference to propulsion shaft intermediate bearings of the plain bearing type, explain EACH of the following:
(a) how change of alignment due to vessel condition is allowed for(2)
(b) why the shaft must be able to move longitudinally (4)
(c) why the aftnost bearing requires a complete bush but other bearings may have the bush only in the lower halt.(4)
8.Quiz. Study Notes
With reference to intermediate shaft bearings of the roller type, describe, with the aid of a sketch, EACH of the following:
(a) how some angular misalignment of the shaft is accommodated;(5)
(b) how longitudinal movement of the shaft is accommodated.(5)
Question 7.
The question is all about roller type intermediate bearings. Many candidates describe thrust block and shaft alignment methods.
9.Quiz. Study Notes
Describe the inspection of a main thrust bearing.(10)
10.Quiz. Study Notes
Describe, with the aid of sketches, the fitting of a hydraulically tensioned bolt suitable for main propulsion shaft flanges.(10)
11.Quiz. Study Notes
Sketch an arrangement for the aft seal of an oil lubricated stern tube bearing.(10)
12.Quiz. Study Notes
Sketch a shaft coupling of the flexible diaphragm type, labelling the MAIN components.(10)
13.Quiz. Study Notes
(a) Describe. with the aid of a sketch, how the alignment of a propeller transmission shaft system may be checked. (8)
(b) State the indications of a high bearing when the shaft is running.(2)
Question 7. Many attempt to describe aligning two shafts together rather than checking the alignment of the shafting. Candidates describe measuring along the shaft rather than the height of the bearings.
14.Quiz. Study Notes
Explain THREE advantages of hydraulically fitted shaft coupling bolts compared to parallel, interference fit bolts.
15.Quiz. Study Notes