Simrad SN90 Purse seine and trawling sonar

Determining the location the transducer

A single answer to the question “where to install the transducer” cannot be given.

The physical location of the transducer depends on the vessel's design and construction, how the hull is shaped, and how the water runs along the hull. There are however a number of important guidelines, and some of these are even conflicting.

The information here must be considered as general advice. Each transducer installation must be handled separately depending on the hull design.

Topics

Location principles

For use as a purse seine sonar, the SN90 transducer is designed to be mounted on the starboard or port side of the vessel. Used as a a trawling sonar, the transducer shall point forward. Its physical location may be:

  • Inside the keel box
  • Inside a dedicated streamlined blister

For trawling purposes, the transducer may be place on a hull unit.

Installation on starboard or port side depends on the fishing gear arrangement on the vessel. Which installation method to choose then depends on the design and physical properties of the hull.

NOTE:

All necessary installation drawings must be prepared by the installation shipyard/and or a naval architect to match each specific installation.

Location principles, keel box

SIMRAD SN90

  1. Distance from bow
  2. Horizontal installation angle (train)
  3. Vertical installation angle (tilt)

Location principles, streamlined blister

SIMRAD SN90

  1. Distance from bow
  2. Horizontal installation angle (train)
  3. Vertical installation angle (tilt)

The transducer must be installed so that the transducer face is slightly angled forward and downwards to cover the desired sector. The coverage of the sonar beam must be taken into account. Which angles to use must therefore be chosen to fit the properties of the hull and the desired area to be covered.

Typical installation angles on previous vessels have been:

SIMRAD SN90

  • Horizontal installation angle (train): 10 to 20 degrees
  • Vertical angle (tilt): 10 to 15 degrees

The distance from the bow (A) must be determined by the vessel’s physical properties, the location of the fishing gear during the fishing operations, and the desired coverage area.

NOTE:

The installation must be approved by the vessel’s national registry and corresponding maritime authority and/or classification society. The shipowner and shipyard performing the installation are responsible for obtaining and paying for installation approval.

 
Copyright ©2018 Kongsberg Maritime AS - All rights reserved. Terms of use | Contact information | Website feedback