Verifying the quality of the hull unit installation
A quality inspection must take place after the hull unit has been installed, and while the vessel is still in dry dock. The inspection shall verify that the sonar room meets the requirements, and that the hull unit has been installed correctly.
Prerequisites
Neither tools nor instruments are required.
Context
The sonar room is the compartment in which the Transceiver Unit, the Power Supply Unit and the hull unit are installed.
Procedure
1 Make sure that the hull unit is installed in the correct location, and that it is suitably oriented for easy maintenance and replacement of parts.
2 Make sure that the unit is not physically damaged, and that the paint-work is clean without dents or scratches.
The physical handling of the unit during the installation may have caused some minor scratches to the paint-work. This can be accepted. However, if rough handling has caused serious damage to the unit, this must be recorded with a written statement and necessary photos, so that corrective actions can be made.
3 Make sure that the physical installation of the unit has been completed.
a Make sure that the welds and brackets used to support the hull unit are substantial enough to hold the unit securely under all operating conditions.
b Make sure that the compartment ("sonar room") in which the hull unit is mounted is clean and dry.
c Make sure that ample space is provided around the unit to allow for maintenance and replacement of parts.
d Make sure that the bolts, screws or studs holding the unit are of the correct size.
e Make sure that the correct flat and shake-proof washers have been used.
f Make sure that all nuts have been tightened properly.
g Make sure that all welds and brackets have been painted with the correct preservation medium to prevent corrosion.
4 Make sure that cable installation has been completed.
a Make sure that all cables leading to and from the unit have been properly mounted and secured.
b Make sure that the unit is securely connected to the ship's ground with an earthing strap.
c Make sure that enough slack has been provided on each cable to allow for maintenance and replacement.
d Make sure that the transducer cables can move freely when the transducer is lowered and hoisted.
5 Make sure that there are no corrosive attacks on the hull unit, mounting flange, installation trunk, support brackets or other parts of the installation.
6 Fill in the result table.
Result
Requirements Results
The compartment in which the hull unit is installed ("sonar room") is clean and dry.  
The sonar room meets all requirements related to the vessel’s watertight integrity.  
The sonar room meets all size and access requirements. The access hatches are suitably constructed and located.  
The sonar room meets all requirements related to insulation, heating and ventilation.  
The sonar room meets all requirements related to electrical installations, including light, power, communication and cabling.  
A bilge pump is installed.  
The sonar room is suitably decked.  
The hull unit is correctly installed with easy access for maintenance and replacement of parts.  
All cables are properly mounted with enough slack.  
The transducer cables can move freely when the transducer is lowered and hoisted.  
The welds and mechanical brackets that support the gantry are strong enough to hold the hull unit securely in place under all operating conditions.  
If a gate valve is used, the welds and mechanical brackets that support the mounting flange are strong enough to hold the hull unit securely in place under all operating conditions.  
The welds and brackets have been painted with the correct preservation medium to prevent corrosion.  
There are no corrosive attacks.  
Date and signature:
Further requirements
If the inspection reveals errors, inaccuracies or unfortunate dispositions related to units, devices or cables, use the Installation remarks form to document these. If necessary, write a full report, and attach high resolution photos.