Kongsberg Simrad MF90, Installation Manual

Page: 25 / 426

476671/B
23
Related topics
Simrad MF90, page 13
System units, page 20
Installing the MF90 system hardware units, page 126
Cable layout and interconnections, page 143
Setting to work, page 186
Technical specifications, page 346
Drawing file, page 364
Hull Unit description
The hull unit is used to lower the transducer down below the ship’s hull when the MF90
system shall be used. When the MF90 system is turned off, the transducer is hoisted for
protection. The hull unit is large and crucial part of the sonar system.
The hull unit is a mechanical construction. It is mounted on the top of the installation trunk.
The installation trunk penetrates the ship’s hull, and allows the transducer to be lowered into
the sea. The hull unit is normally located in the forward part of the vessel. This location is
recommended to avoid the noise from the propellers and the engine.
Caution
When the transducer is lowered, the depth of water under the vessel must be monitored
closely.
If the transducer hits larger objects or bottom, the transducer shaft may be bent, or - in
worst case - it can be broken off. A broken transducer shaft will cause water leakage
through the top of the shaft. If you suspect that the transducer shaft is seriously damaged
with holes, do not retract the transducer to its upper position.
To prevent serious damage to the vessel or the vessel stability, you must have a water
pump and a warning system in the sonar room.
If you forget to hoist the transducer before the MF90 system is turned off, the transducer
is hoisted automatically before the power is disconnected. The transducer is also hoisted
automatically if a serious malfunction occurs to the communication between the bridge
and the hull unit.
In the event of improper operation, the powerful electric motor on the hull unit may cause
serious damage to the equipment and/or injury to personnel. Therefore, before you start
manual operation, read carefully through the relevant operating procedures. You must
familiarize yourself with the correct handling methods and the relevant safety requirements.
The MF90 system can be provided with one of the following hull units:
Simrad MF90