Simrad TRANSDUCER Installation manual

Installation manual

Simrad transducers

Installation principles and guidelines

M A X I M I Z I N G Y O U R P E R F O R M A N C E A T S E A

www.SIMRAD.com

Echo sounder transducers

Installation manual

This document provides a generic description of echo
sounder transducer installation. The information must be
regarded as general guidelines and recommendations on
The installation shipyard must design and manufacture
installation hardware to fit each individual transducer and
vessel.

ly.

851-160164/H

September 2006

Document history

Document number: 851-160164 / ISBN-10: 82-8066-036-4 / ISBN-13: 978-82-8066-036-7

Converted to XML format. Chapters listing all Simrad
transducers and their termination to the General Purpose

Rev.H

September 2006

Transceiver (GPT) are added. Several m inor changes to
other descriptions and illustrations. Interactive version on the
document (CHM format) introduced.

Copyright

©2006SimradHortenAS

The information contained in this document remains the sole property of Simrad Horten AS. No part of this
document may be copied or reproduced in any form or by an y means, and the information containe

dwithin

it is not to be communicated to a third party, without the prior written consent of Simrad Horten AS.

Disclaimer

Simrad Horten AS end eavours to ensure that all information in this document is correct and fairly stated,
but does not accept liability for any errors or omissions. The document can be changed without prior
notice.

Warning

The equipment to which this manual applies must only be used for the purpose for w
designed. Improp e r use or maintenance may cause dam age to the equipment and/or injury to personnel.
The user must be familiar with th e contents of the appropriate manuals before attempting to operate
or work on the equipment.
Simrad disclaims any responsibility for damage or injury caused by improper installation, use or
maintenance of the equipment.

hich it was

Support

If you require maintenance on your Simrad equipment, contact your local dealer. You can also contact
Simrad using the following e-mail address:
e-mail: [e-mail]

Simrad Horten AS

Strandpromenaden 50
P. O. Bo x 1 11
N-3191 Horten,
Norway

Telephone:[phone]
Telefax:[phone]

www.simrad.com

[e-mail]

Installation manual

Table of contents

INTRODUCTION ................................................................ 5

TRANSDUCER LOCATION ...... ............................................ 6

Go deep .....................................................................................................................6

Vessel heave .............................................................................................................6

Noise from protruding objects on the hull................................................................6

Boundary water layer ...............................................................................................7

Propeller noise..........................................................................................................7

Inclination of the transducer face .............................................................................8

Summary and general recommendation...................................................................8

WAYS OF MOUNTING THE TRANSDUCER......................... 10

External mounting ..................................................................................................11

Transducer blister...................................................................................................16

Box keel..................................................................................................................22

Flush mounting in a steel tank................................................................................24

Acoustic window....................................................................................................26

Inside the hull.........................................................................................................28

Drop keel ................................................................................................................30

Retractable transducer ............................................................................................31

CABLE GLANDS ............................................................... 32

Order numbers........................................................................................................32

Cable gland for steel hulls ......................................................................................33

Cable gland for wood or GRP hulls .......................................................................34

Cable glands for small hulls...................................................................................35

Cable splicing.........................................................................................................36

STEEL CONDUIT.............................................................. 37

HANDLING AND MAINTENANCE ...................................... 38

Approved anti-fouling paints..................................................................................39

SIMRAD TRANSDUCERS .................................................. 40

All 12 kHz transducers...........................................................................................41

All 18 kHz transducers...........................................................................................41

All 27 kHz transducers...........................................................................................41

All 38 kHz transducers...........................................................................................42

All 50 kHz transducers...........................................................................................44

All 70 khz transducers............................................................................................45

All 120 khz transducers..........................................................................................46

All 200 kHz transducers.........................................................................................47

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Simrad Echo sounder transducers

All 710 kHz transducers.........................................................................................49

GPT TRANSDUCER TERMINATIONS ................................. 51

Single beam, normal power transducer ..................................................................52

Single beam, high power transducer ......................................................................53

Dual beam (wide or narrow) transducer.................................................................54

Split beam transducer.............................................................................................55

Split beam transducer to single beam transceiver ..................................................56

Single beam transducer to split beam transceiver ..................................................57

Dual frequency, single beam transducer.................................................................58

Sidescan transducer ................................................................................................59

Deep water, split beam transducer..........................................................................60

ES38–10 transducer................................................................................................61

12-16/60 transducer................................................................................................62

50/200 Combi C transducer....................................................................................63

38/200 Combi C transducer....................................................................................64

4

851-160164/H

INTRODUCTION

The purpose of this installation manual is to provide generic
descriptions and illustrations allowing the reader to understand
the basic principles for echo sounder transducer installation.

Note

The information in this document must be regarded as general
guidelines and recommendations only. The installation shipyard
must design and manufacture installation hardware to fiteach
individual transducer and vessel.

Whenever required, the installation shipyard must also have the
installation approved by the applicable maritime authorities.

For detailed information about the transducer to be installed, refer
to the documentation provided with the transducer. Drawings and
descriptions can also be obtained from h

Introduction

ttp://www.simrad.com.

851-160164/H 5

Simrad Echo sounder transducers

TRANSDUCER LOCATION

A single answer to the question where to locate the transducer
cannot be given. It depends very much on the vessel’s
construction. However, there are some important guide lines.

Go deep

The upper water layers of the sea contain a myriad of small
air bubbles created by the breaking waves. In h eavy seas the
uppermost 5 to 10 metres may be air-filled, with the highest
concentrations near the surface. Air bubbles absorb and reflect
the sound energy, and may in worst cases block the sound
transmission totally. Therefore, mount the transducer at a deep
position on the hull.

Consider the situation when the vessel is unloaded, and when it
is pitching in heavy seas.

WARNING
The transducer must never be lifted free of the

water surface.

Not only will the sound transmission be blocked, but the
transducer may be damaged by slamming against the sea surface.

Another reason to go deep is cavitation in front of high power
transducers. Cavitation is the formation of small bubbles in the
water due to the resulting local pressure becoming negative
during parts of the acoustic pressure cycles. The cavitation
threshold increases with the hydrostatic pressure.

Vessel heave

Heave is the up and down movement of the vessel. It disturbs the
echo traces in the echogram, so that a flat bottom is displayed
as a wave. A transducer location in the middle of the vessel
minimises the influence of vessel roll a nd pitch.

Noise from protruding objects on the hull

Objects protruding from the hull, such as zinc anodes, sonar
transducers or even the vessel’s keel, generate turbulence and
flow noise. Also holes and pipe outlets are noise sources. They
may act as resonant cavities amplifying the flow noise at certain
frequencies. Do not place an echo sounder transducer in the
vicinity of such objects, and especially not close behind them.

For the same reason, it is very important that the hull area around
the transducer face is as smooth and level as possible. Even
traces of sealing compound, sharp edges, protruding bolts or bolt
holes without filling compound will create noise.

6

851-160164/H

Boundary water layer

When the vessel forces its way through the sea, the friction
between the hull and the water creates a boundary layer. The
thickness of the boundary layer depends upon vessel speed and
the roughness of the hull. Objects protruding from the hull, and
dents in the hull, disturb the flow and increase the thickness of
the boundary layer. The flow in this boundary layer may be
laminar or turbulent. A laminar flow is a nicely ordered, parallel
movement of the water. A turbulent flow has a disorderly pattern,
full of eddies. The boundary layer increases in thickness when the
flow goes from laminar to turbulent. The figure below illustrates
the boundary layer of a vessel moving through the water.

Transducer location

(CD17004P)

Boundary water layers:
(A) = Turbulent flow
(B) = Laminar flow
(C) = Air bubbles in the water

Furthermore, air bubbles in the sea water are pressed down below
the hull and mixed into the boundary layer. The boundary layer
is thin underneath the forward part of the vessel, and increases in
thickness as it moves towards aft. If the sides of the hull are steep,
some of the air bubbles in the boundary layer may escape to the
sea surface along the vessel sides. It is our experience that a wide
and flat bottom, with a rising angle less than around 13 degrees,
is prone to giving air problems for the transducer. In any case a
transducer location in the forward part of the hull is preferred in
order to minimise the influence of the boundary layer.

Propeller noise

The propulsion propeller is the dominant noise source on most
fishing vessels, research vessels, merchant vessels and pleasure
crafts. The noise is transmitted through the sea water. For
this reason, the transducer should be placed far away from the
propeller, which means on the fore part of the hull. Positions

BAC

851-160164/H 7

Simrad Echo sounder transducers

outside the direct line of sight from the propeller are favourable.
On small vessels with short distances it is advised to mount the
transducer on that side of the keel where the propeller blades
move upwards, because the propeller cavitation is strongest on
the other side. The cavitation starts most easily when the water
flows in the same direction as the propeller blade, and that is to
some degree the case at that side of the keel where the propeller
blades move downwards.

Bow thruster propellers are extremely noisy. When in operation,
the noise and cavitation bubbles make the echo sounder useless,
almost no matter where the transducer is installed. And when not
in operation, the tunnel creates turbulence, and if the vessel is
pitching, the tunnel may be filled with air or aerated water in the
upper position and release this in the lower position. Therefore,
an echo sounder transducer should be placed well away from
the bow thruster.

Inclination of the transducer face

Ideally, the transducer face should be mounted in parallel with the
sea surface when the vessel is in normal trim, as this will provide
the most accurate echo information. However, it is also very
important that the w

In order to ensure laminar flow, the transducer face may be tilted
slightly upwards in relation to the water flow. This allows the
flowing water to meet the face directly, and assures laminar flow.
The inclination angle must however be determined carefully. The
angle must be small on transducers with narrow beam angles. As
a rule of thumb, mount transducers with beam angles smaller
than seven degrees with minimum inclination angle. The smaller
beam angle your transducer has, the smaller the inclination angle
can be.

Ensure that you do not mount the transducer with a negative
inclination angle. This may cause turbulence under the transducer
face, and reduced echo sounder performance.

ater flow over the transducer face is laminar.

Summary and general recommendation

Some of the above guide lines are conflicting, and each case has
to be treated individually in order to find the best compromise.
Generally the propeller noise is the dominant factor, and a
recommended transducer location is in the fore part of the hull,
with maximum distance from the bow equal to one third of the
total length of the hull at the water line.

8

851-160164/H

Transducer location

BA

(CD017004Q)

M

L

General recommendation for transducer location:
(A) = Transducer
(B) = Inclination angle
(L) = Hull length at water line
(M) = Maximum 1/3 of the hull length at water line (L)

If the vessel hull has a bulbous bow, this may well be a good
transducer location, but also here must be taken into consideration
the flow pattern of the aerated water. Often the foremost part
of the bulb is preferable.

(CD17004C)

A

B

Recommended location of the transducer on a bulbous hull:
(A) = Thruster
(B) = Transducer location

851-160164/H 9

Simrad Echo sounder transducers

WAYS OF MOUNTING THE TRANSDUCER

There are many different ways to mount the transducer.

Topics

External mounting on page 11
Transducer blister on page 16
Box keel on page 22
Flush mounting in a steel tank on page 24
Acoustic window on page 26
Inside the hull on page 28
Drop keel on page 30
Retractable t ransducer on page 31

10

851-160164/H

External mounting

Certain transducers have a streamlined housing, and these are
designed for installation outside the hull.

These transducers are mainly used on smaller vessels. A location
approximately 0.5 m aside from the keel may be adequate for
the passage of water between the keel and the transducer. The
figures illustrate external mounting of transducers on steel hulls
and on wood or polyester hulls respectively.

Smooth surface

Ensure that the surface of the transducer face, the hull plating
and putty around the transducer is as even and smooth as
possible. Obstructions on these surfaces will create problems
with turbulant flow.

Mounting screws must not be extruding from the transducer, and
the space around the screws must be filled with a compound (C)
and/or a locking ring.

Ways of mounting the transducer

851-160164/H

11

Simrad Echo sounder transducers

Steel hull

A fairing (A), made by the shipyard, is placed between the
transducer and the hull. It is required in order to adapt for the
deadrise angle of the hull, and it will also house a cable service
loop (B). The fairing can be made of wood or steel, and should
have the same outline dimensions as the transducer. Remember
to create an air outlet (E) on the fairing, and to fill the bolt holes
with a filling compound to ensure a smooth transducer surface.

1

2

3

(CD017007A)

C

4

5

F

B

E

I

A

A

D

(A) = Fairing
(B) = Cable service loop
(C) = Filling compound
(D) = Inclination angle
(E) = Air outlet
(F) = Forward

12

(I) = Threaded rod with nuts and washers, or bolt
(1) = Steel conduit
(2) = Stuffing tube
(3) = Washer
(4) = Rubber gasket
(5) = Packing nipple

851-160164/H

Ways of mounting the transducer

Wood or polyester hull

A fairing (A), made by the shipyard, is placed between the
transducer and the hull. It is required in order to adapt for the
deadrise angle of the hull, and will also house a cable service
loop (B). The fairing is made from wood, polyester or steel, and
should have the same outline dimensions as the transducer. Use
tarred f elt (H) between the fairing and the hull. Remember to
create an air outlet (E) on the fairing, and to fill the bolt holes
with a filling compound to ensure a smooth transducer surface.

1

5

4

3

2

I

(CD17007B)

C

F

G

B

A

(A) = Fairing
(B) = Cable service loop
(C) = Filling compound
(D) = Inclination angle
(E) = Air outlet

D

4

4

H

(1) = Steel conduit
(2) = Stuffing tube
(3) = Washer
(4) = Rubber gasket
(5) = Packing nipple

E

A

(F) = Forward
(G) = Shim (wood)
(H) = Tarred felt
(I) = Threaded rod with nuts

and washers, or bolt

851-160164/H 13

Simrad Echo sounder transducers

Hull with flat bottom

If the vessel’s hull is flat you do not need a fairing. The
transducer is then be bolted directly to the hull using two bronze
or stainless steel bolts (I) and a cable bushing. Note that the
cable bushing must be mounted with proper gaskets (4) under
and over the hull, as well as sealing c ompound (J) around its
body. Also, fill the bolt holes with a filling compound to ensure
a smooth transducer surface.

F

(CD017007C)

4

J

(C) = Filling compound
(F) = Forward
(I) = Threaded rod with nuts and washers, or bolt
(3) = Washer
(4) = Rubber gasket

3

I

C

14

851-160164/H

Ways of mounting the transducer

Toe-in

The primary consideration must be to allow laminar water flow.
In most cases t his is achieved by placing the transducer (A)
parallel with the keel (C). However, if the transducer is located
close to t he bow, the front of the transducer may have a few
degrees (5 to 8°) toe-in towards the bow. If you have a planing
hull, the toe-in must be 0°.

F

C

A

B

(CD017007D)

(A) = Transducer
(B) = 5 to 8° on deplacement hulls, 0° on planing hulls
(C) = Keel
(F) = Forward

851-160164/H 15

Simrad Echo sounder transducers

Transducer blister

With a transducer with circular housing, one recommended
installation method is by using a blister. The transducer blister
must be designed and manufactured by the installation shipyard
to fit the vessel’s size and hull shape.

Mounting and clamping rings

Circular transducers may be provided with mounting and
clamping rings, or with drawings to allow for local production
of these. The m ounting ring is welded to the hole in the
transducer blister, while the clamping ring fits around the edge
of the transducer body. Bolts through the clamping ring into the
mounting ring w ill then secure the transducer between them.
Note that several transducers use direction guides to allow correct
mounting.

Smooth surface

Mounting screws or bolts must not be extruding from the
transducer blister. Ensure that the surface of the transducer face,
the blister, the hull plating and putty around the transducer is as
even and smooth as possible. Obstructions on these surfaces will
create problems with turbulant flow.

Horizontal support bar

Large diameter transducers must be fitted with a horizontal
support bar. This bar can be secured to the mounting ring using
threaded rods.

16

851-160164/H

Ways of mounting the transducer

Example: Large transducer

The illustration below shows a typical transducer blister designed
for a large t ransducer. Note that due to the physical size of
the t ransducer, a U-shaped support bar (E) is used to support
the transducer. The purpose of this support is to prevent the
transducer from being pushed up into the blister in heavy seas.

(CD017010A)

H

E

A

C

E

(A) = Streamlined blister
(B) = Stiffening rib
(C) = Drainage holes
(D) = Inclination angle

G

B

K

I

D

J

F

(G) = Cable service loop
(H) = Stuffing tube
(I) = Minimum 400 mm
(J) = Rounded corners

(E) = U-shaped support bar

(K) = Air outlet

(F) = Forward

851-160164/H 17

Simrad Echo sounder transducers

Example: Small transducer

The illustration below shows a typical transducer blister designed
for a small transducer. The same blister design principles as for a
large transducer apply.

(CD017010B)

E

E

A

B

F

G

C

D

(A) = Streamlined blister
(B) = Mounting ring
(C) = Clamping ring

(E) = Air outlet
(F) = Forward
(G) = Transducer cable

(D) = Guide

Note that the transducer cable must be provided with a cable loop
inside the blister. Observe the vertical forward edge of the blister.
This will guide the water to each side of the blister.

18

851-160164/H

Ways of mounting the transducer

Example: Medium sized transducer without
clamping ring

The illustration below shows a transducer blister designed for a
medium sized transducers. The same blister design principles
apply. Note that the transducer is mounted without a clamping
ring, which makes it necessary to use a different mounting ring
design.

E

E

A

F

B

I

D

G

H

C

(CD017010E)

(A) = Streamlined blister
(B) = Mounting ring
(C) = Bolt
(D) = Self-locking threads

(E) = Air outlet
(F) = Forward
(G) = Transducer cable
(H) = Transducer

Note that the transducer cable must be provided with a cable loop
inside the blister. Observe the vertical forward edge of the blister.
This will guide the water to each side of the blister.

851-160164/H 19