RDG603A23
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Issue 20
Page 34 of 84
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Make sure the exhaust increases then decreases in height as shown in (
Figure 13: Correct Exhaust Installation
21. Hydraulic Drive Transmissions
If an engine is to have a hydraulic drive transmission attached to it instead of a conventional
marine gearbox, a number of points must be observed.
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Bobtail engines (i.e. Engines supplied without a marine gearbox), normally do not have
a gearbox oil cooler fitted. However if a cooler is supplied, this will only be suitable to
cool a conventional marine gearbox.
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Hydraulic drive transmissions generate far more heat than a conventional marine
gearbox. Therefore the size of the oil cooler installed must be calculated by the
hydraulic drive transmission supplier. This is to ensure it has sufficient cooling capacity
and is sized appropriately taking into account:
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Maximum engine power.
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High ambient summer air temperature.
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Summer River/Canal/Sea temperature.
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No additional restriction to engine coolant flow is present.
Skin tanks will also need to be increased by up to approx. 10% to dissipate the additional
heat generated, when a hydraulic bow thruster is used.
Or
An additional separate skin tank of suitable capacity with separate water circulating pump will
need to be fitted for a hydraulic drive system or hydraulic bow thruster.
