Crank Web Deflection
Inspection / Measuring
A5.05. 02.02.01.00
M20
en / 13.06.1997 IB001439 1/4
02
Ĺ
See also:
Spare parts list: B1.05.02.2.2510, B1.05.03.2.1110
Time requirement: 2 Pers./ 1,00 h
Personnel qualification: Chief engineer, skilled engine hand
---------------------------------------------------------------------------------------------------------------------
Operating medium: Heavy fuel and distillate fuel
Inspection:
In the following cases additional measurements have to be made: In the case of suspect or
danger of foundation deformation, e. g.:
• by collision of a ship
• subsidence of the foundation
• bearing or crankshaft damages
• prior and after every docking of a ship.
Tools:
Crank web measuring device W1 1.9425-300
Note:
Crank web deflection means the change in the distance between a pair of crank webs
during one rotation of the crankshaft (Fig. 1). Depending on the location of the engine, the
rigidity of the foundation and of the vessel, different values will be contained when the
vessel is loaded; the values will also depend on whether the engine is hot or cold.
The measurement should therefore, if possible, always be carried out with the vessel in the
same condition as regards loading, not in the dock! Changes under similar conditions
appearing suddenly or over an extended period of time give evidence of subsidence of the
foundation.
Therefore we recommend to file the measuring sheet separately to be able to relate the
crank web deflection values to certain periods of time and to reveal their changes. In the
case of unpermissible changes, the plant has to be realigned and the respective main
bearings must be inspected.
a) Initial position
b) Negative deflection
c) Positive deflection
Fig. 1
cba
To Next Page
Loading...
General