Installation manual

Final tests and measurements
161
851-164510 / Rev.E
3 From full speed, reduce the engine thrust for minimum
speed, and make similar readouts for Retardation.
Speed
(
K
n
o
t
s
)
Bearing 0 degrees
(Knots)
Stable speed Acceleration Retardation
0
2
4
6
8
10
12
14
Table 9 Noise verification
4 Make a dashed line plot of the acceleration noise into the
Noise/speed plot, and a dotted line for the retardation
noise.
By comparing these three plots it should be possible to sort out
if the main noise is caused by flow noise or engine/propeller
noise.
If the main noise is caused by flow noise, the ship’s hull should
be thoroughly inspected during next docking. If the noise is
caused by the engine propeller, ensure that the propeller is not
chipped or corroded.