Hamilton Jet HJ241, Manual

Page: 75 / 202

6.3
6 COMMISSIONING
6.4 V
ESSEL
S
PEED AND
H
ANDLING
T
RIALS
HJ-241 / HSRX
6.4 VESSEL SPEED AND
HANDLING TRIALS
1. Leave the mooring and check that the steering is
operating correctly at “Forward Speed”, at “Zero
Speed” and at “Astern”.
2. Observe the waterjet emerging from the Steering
Nozzles when the vessel is going dead ahead at
speed. The waterjet should be a relatively clean
with an even shape.
3. Check that the Jet Unit and Driveshaft are
running smoothly (no vibration) over the entire
engine operating speed range (i.e. from “Zero
Speed” to “Full Ahead”).
4. Periodically check the surface temperature of the
Bearing Housing and record the temperatures
once it reaches a steady value. Due to friction
caused by the seals, the Bearing Housing is likely
to be warm.
The Bearing Housing operating
temperature should not exceed of 80º C. A faulty
bearing will be heard and felt as a vibration
through the Bearing Housing and is likely to
cause significant heat build-up in the Bearing
Housing.
5. If practical, check the Coupling joint
temperatures. Increased joint temperature may
indicate driveshaft misalignment.
6. Periodically check the hydraulic oil temperature
at the JHPU oil reservoir. Record the temperature
reading after a sustained run at cruising speed
and also after a period of vessel manoeuvering.
7. Record maximum speed (using GPS) and engine
revolutions (Note that strong currents will result in
inaccurate speed readings since the GPS only
provides “speed over ground covered” readings).
At maximum speed the Jet Unit revolutions
should be verified with a hand held tachometer at
the Jet Unit Coupling.
8. Record Vessel speed at varying engine
revolutions if possible.
9. Record observations on vessel trim, loading etc.
6.5 AFTER INITIAL TRIALS (AFTER
ENGINE SHUT DOWN)
1. Refer to Section 8.4“Servicing Intervals” for any
after trials maintenance that may be required.
2. Ensure that all important information recorded
during trials is stored for later reference.
3. Check for water leaks around the Jet Unit
especially at the Transom Seal at the Intake Block
and under the Bearing Housing (Water Seal
leaks).
4. STEEL HULLS ONLY : Check that the insulation
between the Jet Unit and the Hull of the vessel
measures not less than 1000 Ohms.
Refer to
Section 4.3.1“Checking the Insulation” for further
details.
C
AUTION
If a problem is detected, return to
the mooring immediately, at
reduced power. DO NOT operate
the jet unit until the fault has been
repaired. refer to section 7 Fault
Finding.