Installation manual

Trawl hydrophone installation
87
851-165187 / Rev.A
10 The hydrophone that is closest to the main propeller
should be located on the port side of the vessel and have
the greatest tilt.
11 If both hydrophone are located equally distant from the
main propeller, but are tilted differently, the starboard
hydrophone should be tilted the most because underwater
acoustic noise is more prevalent on that side of the vessel.
12 Locating hydrophones at the after end of a bulbous bow
can produce good results. Previously installed sonars in
this area that can subject hydrophones to direct signals
will produce interference.
13 Hydrophone can also be mounted in the after end of echo
sounder shoes as long as the minimum required distances
and ori entation with regard to other underwater acoustic
equipment is observed.
14 Remember that hydrophones ar e to be mounted with their
long axis up (in the vertical plane).
15 Hydrophones installed in blisters should be l ocated away
from the vessel’s keel and as deep as possible on the hull.
16 Hydrophones installed in shoes along the vessel’s keel
should be mounted as deeply as possible.
17 Hydrophone cables that are run in conduit along the
outside of the vessels hull should be ar ranged as to
produce the least amount of underwater acoustic noise as
possible.
18 Blisters and shoes should be as streamlined as possible and
have all o f their corners rounded to minimize the
generation of underwater acoustic noise.
19 Conduit used to run hydrophone cables in the interior of a
vessel’s hull should extend well over its water line.
20 If you install both trawl and purse seine hydrophones, do
not conf use the two types. The Trawl hydrophones are
marked with order number 314-205250, while the Purse
seine hydrophones are marked with order number
314-202275.
21 Other well-founded information or experience regarding
hydrophone installation be available should also be
evaluated even though not directly mentioned in these
instructions.