Important
The ST90 is an advanced product. It is used with other advanced products. There is important information that you need to know.
Watertight integrity
The size, location and design of the sonar room must fulfil all the requirements to the vessel’s watertight integrity.
In the event of a major leak, it must be possible to close all watertight hatches and/or doors to the room to maintain vessel stability and safety. The physical size of the sonar room must be limited, so that in the event of a major leak, the flooding of the room will not induce instability, or cause the vessel to capsize or sink.
For more information, see Sonar room requirements.
Mechanical support of the installation trunk
The installation trunk must be secured to the bulkheads and/or the hull by means of strengthening plates (stiffereners). The dimensions and strength of the plates must be adequate to prevent any vibrations. This is an invariable requirement to ensure the safety of the ST90 system and the vessel.
The shape and locations of the strengthening plates must be determined by the installation shipyard based on the physical properties of the installation trunk, the hull and the space available. Minimum four strengthening plates must be used. Each strengthening plate must extend all the way from the bottom to the top of the installation trunk. Only leave a small gap to allow access to the bolts and nuts used to secure the mounting flange. The minimum plate thickness is 10 mm, but the classification society can specify other dimensions.
Mechanical support of the hull unit gantry
The hull unit gantry must be secured to the bulkhead by means of mechanical support brackets. The dimensions and strength of the support brackets must be adequate to prevent vortex induced vibrations. This is an invariable requirement to ensure the safety of the ST90 system and the vessel.
We recommend that support brackets are placed pointing at minimum three directions with approximately 120 degrees between them.
The mechanical support brackets must be designed and manufactured by the installation shipyard to fit the complete installation in the sonar room. All calculations made to support the design must meet the applicable safety requirements, and apply to the physical properties of the complete installation.
Before you turn on the ST90 system
Before you turn on the ST90 system, make sure that you have sufficient water depth to lower the transducer!
Caution
You must never turn on the ST90 system when the ship is in dry dock. The transducer can be damaged if it transmits in the open air.
When the ST90 system is not used
When you do not use the ST90 system, turn it off.
Note
You must never turn off the ST90 system by means of the on/off switch on the Processor Unit. You must ALWAYS use the Operating Panel.
When you are docking your vessel
You must never set the ST90 system to normal operation when the ship is in dry dock. The transducer can be damaged if it transmits in the open air. To prevent inadvertent use of the ST90 system, pull out the mains plug on the Processor Unit whenever your vessel is in dry dock. Additional precautionary measurers should be considered.
If something breaks down
If you believe that something has broken down, contact your local dealer. A list of all our dealers is provided on our website.
If you are unable to contact a dealer, observe the support information in this publication.
When you want to turn off the ST90 system
You must never turn off the ST90 system by means of the on/off switch on the Processor Unit. When you do not use the ST90 system, turn it off with the Power button on the Operating Panel. If the transducer is lowered when you turn off the ST90 system, it is automatically retracted to its upper position.
Note
If you turn off the ST90 system by means of the on/off switch on the Processor Unit you can damage the software and the interface settings used to communicate with external devices.
Manual operation of the hull unit
In the event of improper operation, the powerful electric motor on the hull unit may cause serious damage to the equipment and/or injury to personnel. Therefore, before you start manual operation, read carefully through the relevant operating procedures.
Note
You must familiarize yourself with the correct handling methods and the relevant safety requirements.
Rules for transducer handling
A transducer must always be handled as a delicate instrument. Incorrect actions may damage the transducer beyond repair. A physical blow to the transducer face may easily damage one or more elements. Observe these transducer handling rules:
•  Do not activate the transducer when it is out of the water.
•  Do not handle the transducer roughly. Avoid impacts.
•  Do not expose the transducer to direct sunlight or excessive heat.
•  Do not use high-pressure water, sandblasting, metal tools or strong solvents to clean the transducer.
•  Do not damage the outer protective skin of the transducer.
•  Do not step on the transducer cables.
•  Do not damage the transducer cables. Avoid exposure to sharp objects.