Furuno FSV-35 Installation Manual page 9

1.1.2 Guideline for how to shorten the retraction tank
Shorten the tank as necessary so that the transducer positions well below the keel
when it is fully lowered. The following table provides guidelines for shortening the tank.
Refer also to the retraction tank installation drawing at the back of this manual.
Installation
Method
Stroke
1200 mm
stroke
1600 mm
stroke
Note 1: For the 1200 mm stroke hull unit, the transducer will not fully protrude unless
the tank is shorted by at least 280 mm from the bottom, and can not be fully retracted
if more than 290 mm.
Note 2: For the 1600 mm stroke hull unit, the transducer can not be fully retracted if
the tank is removed more than 290 mm.
Note 3: When maximum length is removed and "D" is minimum, the effect of air foam
is minimized because the transducer fully protrudes in water.
Guideline for the installation of the retraction tank
• Install, if possible, the tank on the keel where the tank can be most firmly fixed.
• Install the reinforcement ribs as near as possible to the top of the retraction tank,
allowing space for tightening of nuts and bolts.
Retraction tank
250-300 mm
• Fit a doubling plate (a plate added to another to give extra strength or stiffness) of
1200 mm diameter to the location where the retraction tank is welded to the hull bot-
tom. See the outline drawing at the back of this manual.
• Inscribe the bow mark on the attachment flange.
Remove 280 -290 mm from the bottom.
The length "D" must be less than 1170 mm.
Remove loss than 290 mm from the bottom.
The length "D" must be less than 1150 mm.
1. HOW TO INSTALL THE SYSTEM
D
Reinforcement rib
No. of ribs: Minimum 4
Thickness: at least 12 mm
D
1-3