Installing the transducer dock
The transducer dock is mounted on the top of the gate valve. The top mating surface is in parallel with the sea surface during normal operating conditions. The transducer dock protects the transducer when the SU90 system is not used.
Prerequisites
This task must take place in dry dock. The shipyard must provide all necessary tools and manpower. The following specific items are required for this task:
•  Silicone grease
•  Anti–seize lubricant
•  Torque wrench
•  Lifting arrangement
•  O-ring
•  Mounting hardware
It is assumed that the gate valve has been installed.
Note
The transducer dock is heavy. Always use appropriate lifting equipment to minimize risk of personnel injury or equipment damages. Only certified equipment must be used.
Context
The transducer dock can be supplied by Kongsberg Maritime. Alternatively, you can design and manufacture a custom transducer dock.
Only the basic steps of the task are offered. Additional procedures with more information and/or details must be provided by the installation shipyard to fit the vessel properties.
•  The top mating surface of the gate valve must be protected with a wooden cover at all times until the transducer dock is installed. It is very important that this surface is clean and undamaged, to ensure watertightness after the transducer dock has been installed.
•  The top mating surface of the transducer dock must be protected with a wooden cover at all times until the hull unit is installed. It is very important that this surface is clean and undamaged, because it must be watertight after the hull unit has been installed.
Procedure
1 Attach the necessary tackles to the transducer dock, and make sure that the unit is lifted with the correct side up.
Verify that the bottom of the transducer dock will match the flange on the gate valve.
2 Lower the transducer dock down into the hull unit compartment, but stop when the unit is a few centimetres above the gate valve.
Note
Do not damage any of the mating surfaces.
3 Prepare the gate valve.
a Remove the protective cover from the mating surface on the gate valve.
b Verify that the mating surface on the gate valve is clean and undamaged.
c Wipe a thin film of silicone grease on the O-ring and place it in the groove on the gate valve.
4 Attach the nuts and washers while the transducer dock is still suspended.
5 Lubricate the threads with a high grade commercial anti-seize lubricant.
6 Orientate the transducer dock so that it points in the desired direction.
7 Lower the transducer dock carefully onto the gate valve while tightening the nuts.
8 Disconnect and remove the tackles from the transducer dock.
9 Tighten the nuts to torque 472 Nm.
10 Depending on mechanical support provided by the existing decks and/or bulkheads, design, manufacture an install additional mechanical support for the transducer dock.
The necessity of such mechanical support must be decided by a naval architect.