Prerequisites
The vessel is in dry dock. The SU90 system is turned off. The shipyard must provide all necessary tools and manpower.
You need a suitable screwdriver or a large coin to open the Motor Control Unit cabinet. You also need a 4 mm Allen key.
Two persons are needed to do the task.
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One person must stay in the sonar room to operate the hull unit. |
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One person must stay in the dry dock, under the hull, to make sure that the transducer is not lowered too far down. |
Proper oral communication must exist between the sonar room and the dry dock personnel.
Context
On larger hull units, the hoist motor is provided with a motor brake. The motor brake must be released before the transducer is manually lowered or hoisted.
NoteWhen not in use, the hand crank must always be placed inside the Motor Control Unit. When removed from its storage position the hand crank releases a safety switch which disables hull unit operation.
The transducer is covered with a thick red or black protective coating made of a special plastic type. The protective coating is a vital part of the transducer. It is very important that neither this coating nor the internal parts of the transducer are damaged during the handling, installation or cleaning. Any holes and/or scratches in the transducer surface will allow water to penetrate the transducer. If a leak occurs, the transducer must be replaced.