Document: 990-0000046-1000
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Caution
Prior to cutting the cable for any of the above reasons,
a careful visual examination should be made
for any signs of physical damage.
With both ends disconnected, the tow cables should measure between 100 Mega-ohms and
infinity between conductors with a 500 VDC Meg ohmmeter. When using a Simpson 260 Multi-
meter, all cables wire-to-wire or wire-to-shield should measure infinity. Any leakage on the
multi-meter indicates cable leakage.
Damaged Tow cable Connector
The towfish has a trip line that prevents the vehicle from hanging up on a snag. When the line
trips, the cable connection to the fish disconnects exposing the high voltage pins to seawater. Pin
corrosion will start to occur as long as power is still applied. If the power is not immediately
removed, and the cable is not immediately retrieved and the connector flushed out with fresh
water, there may be permanent damage to the connector. This will require cable re-termination.
7.3
R
EPAIR
7.3.1
D
AMAGED
T
AIL
F
INS
Tail fins are susceptible to being bent, banged up, and even torn off the towfish. A bent tail fin
may cause the towfish to veer from its intended towing path and operating depth. An extra set of
fins should always be available in the event they are damaged or lost. Figure 7-5 is a drawing of
the fins in case they have to be remotely manufactured in an emergency.
7.3.2
T
RANSDUCERS
Transducers are exposed and subject to damage by hitting a bulkhead or any other fixed object
during fish deployment and retrieval. Each transducer is made up two individual arrays, a short
and a long string. Both port and starboard strings are identical.
The strings are not field-repairable. A spare array set should be readily available. The transducer
array bulkhead connections are located in four quadrants as shown in Figure 7-6 when viewing
the end cap. The long/short designations refer to the relative lengths of the strings.
7.3.3
T
OWFISH
R
EARMING
When the safety link trips, the towfish must be rearmed with the appropriate plastic shear pin.
Spare shear and cotter pins are in the spares kit.
Do not replace the plastic shear pin with a metallic one unless it is a dire emergency. A metal pin
may not shear if the towfish hangs on a snag. This may result in losing the towfish if the tow
cable separates.
