Kongsberg EM 122, Installation Manual

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EM 122
Gondola
A gondola is like a pod hanging down from under the ship’s keel and this pod is
housing the transducers. There is a gap between the transducers and the ship’s hull
that will allow aerated water and air bubbles to pass trough this gap and not be pushed
down and under the transducer faces. This is often the preferred installation approach
for Kongsberg Maritime and the method that gives the optimum weather window and
system performance. The gondola can be tailored to fit the ship and also the scope
of supply. Kongsberg Maritime have been involved in all sizes of gondolas, from the
smallest wit only an EM 710 system to the largest one housing all transducers in an
integrated acoustic outfit.
See Gondola – 1 x 2 degree system on page 37
Logistics and references
Logistics and references
Logistics and references Safety - Refer to the general safety procedures.
Personnel - Trained mechanical workers
Ship location
- Dry dock
Special tools
- Torque wrench
Protection
- Protective paint, zinc anodes
References - None
Procedure
1 Design and manufacture the transducer gondola.
• The gondola must hold the two casings; one for the TX and one for the RX
transducer arrays. The appropriate drawings describing these casings are
included in the Drawing File.
• The gondola will be water filled. To let the air escape, make a suitable hole in
the rear end close to the vessel’s hull.
• Our recommendation is to place an “debris knife” in the forward end of the
gondola.
2 Prepare the inside surface protection of the gondola. Paint with protective paint,
and mount zinc anodes.
3 Mount the transducer gondola under the vessel’s hull.
4 Check the inside surface protection of the gondola.
• Add paint or zinc as required.
5 Protect the outer surface of the gondola.
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