Installation example (off keel/with blister)
The illustration demonstrates the mounting principles for a standard trunk.
Image
Note
The drawing is not to scale.
A As short a possible
B 1090 mm (Maximum)
C 1200 mm (Minimum)
D 40 mm (Approximately)
E Strengthening knee plates (stiffereners)
F Streamlined blister
G 610 mm (Approximately)
H 1200 mm (Approximately)
I Deflection brackets must only be welded to the shell-plating. Thickness: 6 mm (Minimum)
The streamlined blister is an option. The blister may work well on smaller vessels. This is because it allows you to bring the installation trunk and hull unit down closer to the keel. A lower position will increase the depth of the transducer relative to the hull. The circular opening in the blister must have the same diameter as the inside diameter of the installation trunk.
Important
The installation trunk must be secured to the bulkheads and/or the hull by means of strengthening plates (stiffereners). The dimensions and strength of the plates must be adequate to prevent any vibrations. This is an invariable requirement to ensure the safety of the SU90 system and the vessel.
The shape and locations of the strengthening plates must be determined by the installation shipyard based on the physical properties of the installation trunk, the hull and the space available. Minimum four strengthening plates must be used. Each strengthening plate must extend all the way from the bottom to the top of the installation trunk. Only leave a small gap to allow access to the bolts and nuts used to secure the mounting flange. The minimum plate thickness is 10 mm, but the classification society can specify other dimensions.