Furuno CSH-23, Installation Manual

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3
3. MOUNTING THE EQUIPMENT
3.1 Mounting the Hull Unit and Receiver Unit
Location of hull unit
Decide the location of the hull unit through consultation with the dockyard and shipowner.
When deciding the location, the following points should be taken into account.
• Select an area where propeller noise, cruising noise, air bubbles and interference from turbu-
lence are at a minimum. Generally, the point at 1/3 to 1/2 of the ship’s length from the bow
on or near the keel is optimum. On-the-keel installation is advantageous for minimizing oil
consumption in comparison with off-the-keel. If the hull unit can not be installed on the keel,
the center of the retraction tank should be within 600 mm of the keel to prevent a rolling
effect.
Figure 3-1 Hull unit mounting location
• Select a place where the hull bottom is flat and the draft is sufficiently deep. Normally, the
transducer should protrude at least 500 mm beyond the keel to minimize the effect of air
foam and bubbles.
• Select a place where interference from other equipment is minimal. The hull unit should be
at least 2.5 m away from the transducers of other equipment.
• No obstacle should be in the fore direction since it causes a shadow zone and aerated water,
resulting in poor sonar performance.
• The space shown in the figure on the next page is required around the hull unit for wiring and
maintenance.
• If the ambient temperature of the unit is below 0
°
C, provide the sonar compartment with a
heater to keep the temperature above 0
°
C.