Simrad 38-9 DATASHEET

Installation manual

Simrad 38-9

38 kHz Single beam transducer

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

Simrad 38-9

Installation manual

This document provides a general description of how
to install the Simrad 38-9 Single beam transducer. The
information must be regarded as general guidelines and
recommendations only. The installation shipyard must
design and manufacture installation hardware to fit the 38-9
transducer on each individual vessel.

305265/A

August 2006

Document history

Document number: 305265 / ISBN-10: 82-8066-074-7 / ISBN-13: 978-82-8066-074-9
Rev.A August 2006

Original issue.

Copyright

©2006SimradHortenAS

Disclaimer

The information contained in this document remains the sole property of Simrad Horten AS. No part of this
document may be copied or reproducedin any form or by any means, and the information contained within
it is not to be communicated to a third party, without the prior written consent of Simrad Horte

nAS.
Simrad H orten AS endeavours to ensure that all information in this d ocument is correct and fairly stated,
but does not accept liability for any errors or omissions.

Warning

The equipment to which this manual applies must only be used for the purpose for which it was
designed. Improper use or maintenance may cause damage to the equipm ent and/or injury to personnel.
The user must be familiar with the contents of the appropriate manuals before a

ttempting to operate
or work on the equipment.
Simrad disclaims any responsibility for dam age or injury caused by improper installation, use or
maintenance of t he equipment.

Support

If you require maintenance on your Simrad equipment, contact your local d ealer. 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 T HE TRANSDU CER......................... 10

Transducer blister ...................................................................................................11

Box keel..................................................................................................................17

Flush mounting in a steel tank................................................................................19

Acoustic window.................................................................................................... 21

Inside the hull .........................................................................................................23

Drop keel ................................................................................................................25

Retractable transducer ............................................................................................26

CABLE GLANDS ............................................................... 27

Order numbers........................................................................................................27

Cable gland for steel hulls......................................................................................28

Cable gland for wood or GRP hulls .......................................................................29

Cable glands for small hulls ...................................................................................30

Cable splicing.........................................................................................................31

STEEL CONDUIT.............................................................. 32

HANDLING AND M AINT ENANCE ...................................... 33

Approved anti-fouling paints..................................................................................34

DRAWING FILE ............................................................... 35

Single frequency, single beam, low pow er transducer connection.........................36

Outline dimensions.................................................................................................37

Mounting arrangement ...........................................................................................38

Mounting ring.........................................................................................................40

Blister assembly .....................................................................................................42

Blister design..........................................................................................................44

305265/A 3

Simrad 38-9

4

305265/A

INTRODUCTION

The purpose of this manual is the provide the basic information
required to install the 38-9 Single beam transducer.

Note that although drawings are provided to explain the
installation principles, the installation shipyard must provide the
final drawings required to fit each individual vessel. Also, w hen
applicable, the installation shipyard must have the drawings and
installation approved by the proper authorities.

Transducer order number: KSV-203635.
A cable gland kit for steel hull is included with the delivery.

Other cable glands must be ordered separately.

Transducer installation

The next chapter in this manual provides general guidelines
for transducer installation. The drawings specific for the 38-9
transducer are located in the Drawing file.

Introduction

Technical specifications

Refer to the 38-9 Product specification.

Additional parts

The following items can be supplied by Simrad to facilitate
installation:

• Mounting ring: Order number 499–203336

• Transducer cable (for extension): Order number 642–016604

305265/A 5

Simrad 38-9

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 heavy seas the
uppermost 5 to 10 metres may be air-filled, with the highest
concentrations near the s urface. 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 and 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 t ransducer 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

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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

305265/A 7

Simrad 38-9

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 k eel where the propeller blades
move upwards, because the propeller cavitation is strongest on
the other side. The cavitation starts m ost 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 t he 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 c ase 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

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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

305265/A 9

Simrad 38-9

WAYS OF MOUNTING THE TRANSDUCER

There are many different ways to mount the transducer. These
are the recommended methods to mount a circular transducer.

Topics

Transducer blister on page 11
Box keel on page 17
Flush mounting in a steel tank on page 19
Acoustic window on page 21
Inside the hull on page 23
Drop keel on page 25
Retractable transducer on page 26

10

305265/A

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 mounting 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 r ing will then secure the transducer between them.
Note that several transducers use direction guides to allow correct
mounting.

Ways of mounting the transducer

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.

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11

Simrad 38-9

Example: Large transducer

The illustration below shows a typical transducer blister designed
for a large transducer. Note that due to the physical size of
the transducer, a U-shaped support bar (E) is used to support
the t ransducer. 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 c orners

12

(E) = U-shaped support bar
(F) = Forward

(K) = Air outlet

305265/A

Ways of mounting the transducer

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.

305265/A 13

Simrad 38-9

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

14

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.

305265/A

Ways of mounting the transducer

Common guidelines

The best performance is obtained with a blister height of 40 cm
or more. A streamlined shape and rounded edges reduce the flow
noise. A vertical leading edge or front will guide the aerated
water to the sides of the blister. The orientation of the blister
should follow the water flow.

The interior of the blister must be filled with sea water. Use
drainage holes in the bottom and an air outlet on the top. The
water pressure behind the transducer will then compensate for
the outside pressure during vessel movements in rough sea.

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

The transducer cable penetrates the hull in a stuffing tube. Leave
an adequate loop of the cable behind the transducer for easy
mounting or removal of the transducer.

Toe-in

The primary consideration must be to allow laminar water flow.
In most cases this is achieved by designing the blister in parallel
with the keel. However, if the blister is located close to the bow,
the front of the blister may have a few degrees toe-in towards
the bow.

A

C

B

(CD17010C)

(A) = Keel
(B) = Blister
(C) = Toe-in angle

Physical location

The blister is placed on one of the sides of the hull, and the
distance from the keel is a trade off between a close distance
giving a turbulent flow of water in a narrow passage, and a large
distance bringing the transducer higher up and also more affected
by vessel roll. Normally a distance of approximately 1 m is a
good compromise.

305265/A 15

Simrad 38-9

Observe the horizontal and vertical distances (X and Y) between
the keel and the transducer blister. On a medium sized vessel, the
horizontal distance (X) should be approximately 1 meter. The
vertical distance (Y) must in general be as small as possible. This
is important to prevent the keel from shadowing t he transducer
beam in shallow waters.

(CD17010D)

B

A

Y

X

(A) = Keel
(B) = Transducer blister
(X) = Horizontal distance between keel and blister
(Y) = Vertical distance between the blister surface and the keel

16

305265/A

Box keel

Ways of mounting the transducer

Vessels with a box keel may use this for transducer installation.
The box keel is already the deepest part of the vessel. If the

box keel is too narrow to accommodate the transducer, it can be
widened, either symmetrically or to one side only. In the last
case the installation could also be described as a blister merged
into the keel.

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 mounting ring is welded to the hole in the box keel,
while the clamping ring fits around the edge of the transducer
body. Bolts through the clamping ring into the mounting ring
will 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 box
keel. Ensure that the surface of the transducer face, the box,
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.

305265/A 17

Simrad 38-9

Example

The figure below illustrates a symmetrical box keel installation.

(CD17011A)

D

C

B

E

A

(A) = Box keel
(B) = U-shaped support bar (only required on large transducers)
(C) = Stuffing tube
(D) = Cable in steel conduit
(E) = Cable service loop

18

305265/A

Flush mounting in a steel tank

Flush mounting is used on very large vessels with a hull so deep
that no air bubbles are found below the hull, and on vessels
operating in shallow harbours or waters, where a protruding
blister can not be accepted.

The standard procedure for flushmountingonasteelvesselis
to weld a steel tank inside the hull, and mount the transducer
into this tank.

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 mounting ring is welded to the hole in the hull plating,
while the clamping ring fits around the edge of the transducer
body. Bolts through the clamping ring into the mounting ring
will then secure the transducer between them. Note that several
transducers use direction guides to allow correct mounting.

Ways of mounting the transducer

Smooth surface

Mounting screws or bolts must not be extruding from the hull
plating. 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.

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.

Water filled

As for a blister, the interior of the tank must be filled with water.
This can be accomplished by air release through a steel tube,
which is extended either to open air 1.5 m above the water line
or to the water outside the hull at a point higher than the tank
interior. If the tube is extended to open air, drainage must be
provided with leakage at the transducer flange or a separate hole
in the tank bottom.

305265/A 19

Simrad 38-9

Example

Transducer mounting in a steel tank is shown in the figure below.

G

F

A

B

C

(A) = Steel tank
(B) = Water
(C) = Drainage hole
(D) = Cable service loop
(E) = Steel tube for air outlet
(F) = Stuffing tube

E

D

(CD17012A)

(G) = Cable in steel conduit

20

305265/A

Acoustic window

Vessels operating in arctic waters need special attention on
transducer installation. Floating blocks of ice may damage even
a flush mounted transducer face. For this situation Simrad offers
arctic tanks in different sizes.

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 mounting ring is welded to the hole inside the
steel tank, while the clamping ring fits around the edge of the
transducer body. Bolts through the clamping ring into the
mounting r ing will then secure the transducer between them.
Note that several transducers use direction guides to allow correct
mounting.

Ways of mounting the transducer

Smooth surface

Mounting screws or bolts must not be extruding from the
acoustic window. Ensure that the surface of the window, 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.

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21

Simrad 38-9

Example

The transducer shown in the figure below is mounted inside the
tank behind a strong acoustic window which could be made of
polycarbonate. The tank is filled with oil.

A

B

(CD017012B)

(A) = Steel tank
(B) = Oil
(C) = Acoustic window
(D) = Cable service loop
(E) = Stuffing tube

F

G

E

D

C

(F) = Cable in steel conduit
(G) = Oil inlet

22

305265/A

Inside the hull

The transducer can also be mounted inside the hull.
An installation of the transducer inside the hull, and sounding

through the hull, requires a good acoustic contact between the
transducer face and the hull. Build a tank around the transducer
and fill it with a liquid. Oil used in hydraulic systems is a well
suited liquid for this purpose. It contains no gas bubbles and
is non-corrosive.

Typical values of the two way loss are 3 dB for polyester, 6 dB
for aluminium and 10 dB for steel. Hulls made of wood or a
sandwich type with foam in the middle, attenuate the sound so
much that through hull sounding must be regarded as impossible.
The loss varies with the distance between transducer face and
the hull. The best result is obtained when the distance is half a
wavelength. Consult Simrad for advice. In addition to the loss,
the beam pattern is degraded, because a larger area of the hull is
set into vibrations.

Ways of mounting the transducer

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 mounting ring is welded to the hole inside the
steel tank, while the clamping ring fits around the edge of the
transducer body. Bolts through the clamping ring into the
mounting r ing will 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
acoustic window. Ensure that the surface of the window, 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.

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Simrad 38-9

Example

The transducer shown in the figure below is mounted inside the
hull. The tank is filled with oil.

G

D

A

B

(CD017012C)

(A) = Steel tank
(B) = Oil
(C) = Hull plating
(D) = Cable service loop
(E) = Stuffing tube
(F) = Cable in steel conduit

H

F

E

C

(G) = Hole for oil filling
(H) = Air outlet

24

305265/A

Drop keel

Ways of mounting the transducer

The use of a drop keel with the purpose of stabilising the vessel
is well known.

A drop keel is also a superior platform for echo sounder
transducers. Such instrument keels have been built, mainly on
research vessels, often protruding as far as three meters below
the hull. At that depth, the water is free of air bubbles up to
very high sea s tates. The vessel is then able to perform reliable
acoustic measurements in open sea a larger part of the year.

(CD017012D)

A

B

C

(A) = Instrument keel shaft
(B) = Lowered position
(C) = Bottom view

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Simrad 38-9

Retractable transducer

Hull units allowing the transducer to be lowered and hoisted are
commonly used for horizontal looking sonars. When not in use,
the transducer is retracted into a trunk.

The retractable hull unit is more expensive than a blister, but on
vessels with a hull where it is difficult or impossible to install a
blister, it may still be worth while. The principles of a hull unit
with a retractable transducer is shown below.

Vessels without a keel and with a wide, flat bottom is an example
where a retractable hull unit can be the only acceptable method
for bringing the echo sounder transducer below the boundary
layer.

D

(CD017012E)

C

(A) = Transducer

B

E

A

26

(B) = Trunk
(C) = Transducer shaft
(D) = Transducer shaft sleeve
(E) = Keel

305265/A

CABLE GLANDS

The transducer cable must pass through the hull using approved
cable glands for the type of vessel in question.

A steel cable gland is normally used on professional vessels
with steel hulls. A bronze cable gland can be delivered as an
option for vessels with wood or fibreglass hulls. Vessel not to be
classified can as an option use a cable gland made of plastic.

Note

Simrad strongly recommends that a length of conduit is fitted
around transducer cable glands made of steel or bronze and
extended over the water-line inside the vessel. This precaution
reduces the danger of flooding in the event of gland failure and
transducers installed in this manner are also easier to replace.

Some vessels may experience difficulties finding suitable areas
of the hull for mounting transducer cable glands due to existing
water tanks, concrete ballast or other obstacles. A possible
solution in such cases is to run the transducer cables in a steel
conduit aft along the hull until a suitable cable gland location is
available. The respective cable gland can then be installed as
described in the following instructions.

Cable glands

Note

Simrad takes no responsibility for the correct installation of
cable glands, associated hull modifications and/or structural
support of transducer cable penetration. These activities are
subject to individual approval by the respective classification
society for the vessel in question.

Order numbers

The cable glands described in this chapter are available as kits
from Simrad. Observe the following order numbers.

Steel hull cable gland kit (steel): 599-202216
Wood/GRP hull cable gland kit (bronze): 119-038200
Small hull cable gland kit (plastic): 599-202182

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Simrad 38-9

Cable gland for steel hulls

This cable gland kit is designed for steel vessels. It must be
welded to the hull plates.

ø35

A

ø65

F

A

B

C

D

C

E

(CD17008A)

(A) = Steel conduit
(B) = Stuffing tube, DNV approved carbon steel st52.3
(C) = Washers, 24 x 8 x 2 mm
(D) = Rubber gasket
(E) = Packing nipple. Make sure that you do not damage the

transducer cable by tightening the packing nipple too hard!
(F) = Cable to the echo sounder (or a junction box)

The cable gland kit includes all of the necessary parts needed to
install t he unit except screws.

Simrad recommends that a one inch steel conduit (that the
transducer cable will be run through) with an inside threaded
diameter of three-quarter inches is welded to the gland’s stuffing
tube. The conduit must extend to above the vessel’s water line.

28

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Cable gland for wood or GRP hulls

A bronze cable gland kit is available for wood and GRP vessels.

Cable glands

F

A

B

C

B

C

C

B

(A) = Packing nipple. Make sure that y
transducer cable by tightening

the packing nipple too hard!

E

D

(CD17008B)

ou do not damage the

(B) = Washers
(C) = Rubber gaskets
(D) = Hole diameter 28 mm
(E) = Steel conduit
(F) = Cable to the echo sounder

The cable gland kit includes a
install the unit except scr

Simrad recommends that a
transducer cable will b
diameter of three-qua
nipple. This connect
extend to above the v

305265/A 29

ews.

e r un through) with an inside threaded

rter inches is attached to the gland’s packing

ion must be watertight, and the conduit must

essel’s water line.

(or a junction box)

ll of the necessary parts needed to

one inch steel conduit (that the

Simrad 38-9

Cable glands for small hulls

This cable glands made of plastic is designed for those smaller
vessels that do not need to be classified.

A

J

B

A

C

D

E

(CD17008C)

F

G

H

I

(A) = Packing nut (bronze). Ensure that you do not to damage
the transducer cable by tightening the packing nut too hard!

(B) = Rubber gasket
(C) = Plastic disk
(D) = Rubber gasket
(E) = Stuffing tube
(F) = Backing nut (bronze)
(G) = Backing washer (plastic)
(H) = O-ring 42.5 x 3.0 N
(I) = O-ring 39.5 x 3.0 N
(J) = Cable to the echo sounder (or a junction box)

Stuffing tube hole diameter: 36 mm ±1.5 mm.
Apply ample amount of sealant between the backing washer (H)

and the hull plate.
The cable gland kit contains all the listed parts, except the sealant.

Note

The two O-rings must be clean, in
or other defects which could af

good condition and free of cuts

fect their watertight integrity.

30 305265/A

Cable splicing

Cable glands

If you need to cut the transducer cable, you must splice it
correctly.

Note

DO NOT solder the wires together with only electrical tape for
insulation, as this will result in electrical noise and reduced
operational performance.

To splice the cable, use a metal junction box. The chassis of the
junction box must be grounded, but the cable shielding must
NOT be connected to the junction box ground.

305265/A 31

Simrad 38-9

STEEL CONDUIT

It is strongly recommended to lay a steel conduit from the
transducer’s cable gland to the echo sounder transceiver, and to
pull the transducer cable through this conduit. There are two
reasons for this.

• First, it will make it easier at a later stage to replace the
transducer.

• Second, noise and interference from other electrical equipment
is greatly reduced.

With a steel conduit the installation will satisfy the EU
regulations for EMC interference. Without a steel conduit, there
is a risk of reduced echo sounder performance.

The steel conduit must be unbroken and watertight from the
transducer to above the water line. From there, the cable can
be pulled further, or a junction box can be installed to facilitate
further connections. Note that the steel conduit must act as
a continuous electrical screen all t he way. To ensure proper
shielding, the conduit must be electrically connected to the echo
sounder transceiver chassis.

Steel conduit dimensions:

• minimum 35 mm inner diameter

• minimum 6 mm wall thickness (4.5 mm if galvanised)

If two or more transducers a re installed close to each other it is
possible to pull their cables in the same steel conduit, provided
the conduit diameter is increased accordingly. However, for easy
replacement it is recommended that each transducer has its own
steel conduit.

32

305265/A

HANDLING AND MAINTENANCE

Do not lift the transducer by the cable.
Some transducers are delivered with a cover plate on the face

for protection during transport. Let this plate stay on as long as
possible, but do not forget to remove it before the vessel goes
into the sea.

An anti-fouling paint may be applied to the transducer face.
Because some paint types may be aggressive to the polyurethane
in the transducer face, please consult Simrad’s list of approved
paints.

Note

Arctic tanks have acoustic windows made of polycarbonate.
These must neither be painted nor cleaned with chemicals.

Handling and maintenance

During dry docking of the vessel, the transducer face may be
cleaned for shells and other marine fouling. Be careful not to
make cuts in the transducer face. Use a piece of wood or a very
fine grade emery paper.

305265/A 33

Simrad 38-9

Approved anti-fouling paints

This is Simrad’s list of approved antifouling paints on
polyurethane transducer housing.

Jotun

Head office address: P.O.Box 2021, N-3248 Sandefjord, Norway
Website: w

ww.jotun.com.

1 Racing
2 Non-stop
3 Safeguard Universal primer (125 micron)
4 Antifouling SeaQuantum Ultra (125 micron)
5 Antifouling Seaguardian

International Marine Coatings

Address: World-wide offices
Wesite: w

ww.international-marine.com.

1 Intersleek tie coat + 425 FCS

• BXA386/BXA390/BXA391 Grey

• HKA563/HKA570/HKA571 Ye llow

• Mix BXA386, BXA390 and BXA391 first, then apply.
When dry, mix HKA563, HKA570 and HKA571, apply.

2 Intersmooth 360 Ecoloflex SPC
3 Micron Ekstra

Hempel IFA Coatings

Head office address: Hempel A/S, Lundtoftevej 150, Kgs.
Lyngby, DK-2800 Copenhagen, Denmark

Website: w

ww.hempel.com.

1 Hempel A/F Classic 76550

Note

Refer to the manufacturer’s documentation and data

sheets for

a complete procedure.

34 305265/A

DRAWING FILE

This chapter contains relevant drawings related to the electrical
and physical installation of the 38-9 Single beam transducer.

Note

The mechanical drawings are f or information and guidance only.
They are not in scale. All dimensions are in mm unless otherwise
is noted.

Observe the maximum torque (31 Nm) when the transducer is
bolted into the mounting ring!

The original installation drawings are available on PDF and
AutoCad format. Visit w

In addition to the drawings available in this chapter, an additional
drawing is provided on the web site. This is drawing 599–203664
describing an optional steel tank for the transducer.

Drawing file

ww.simrad.com to download.

Drawings

Single frequency, single beam, low power transducer connection

on page 36

Outline dimensions on page 37
Mounting arrangement on page 38
Mounting ring on page 40
Blister assembly on page 42
Blister design on page 44

305265/A 35

Simrad 38-9

Single frequency, single beam, low power
transducer connection

This is the termination of the transducer cable from a single
frequency, single beam transducer to the transducer socket on the
General Purpose Transceiver Unit (GPT). The other end of the
cable is permanently fixed to the transducer.

All transducer cables must be run in steel conduits. Use a flexible
conduit closer to the transceiver.

Low power output is achieved when the GPT is equipped with
a single transmitter board. In most systems, this will result in
a 2 kW output power, but older GPTs may only be capable of
supplying 1 kW.

Transducer
cable

W802-1

Rev.E

A

N

B

C

D

E

F

H

Junction Box (1:1)

(Optional)

Screen Connect to plug housing

GPT Transducer

M

L

K

J

Single frequency, single beam, low power termination

Note

Thecablescreenmust not be connected to the s hip’s ground
through the junction box.

socket

D
C

The cable screen can be co
the junction box chassi

nnected to the junction box chassis, but
ust not be connected to ship’s ground.

sm

36 305265/A

Outline dimensions

Drawing file

ø310

Cable length: 20 m
Cable diameter: 10.9 mm

ø340

ø150

ø71

150 100

ø336.5

Note:
All measurements are in mm unless otherwise specified.
The drawing is not in scale.

30

o

ø18

R5

ø12

12

CD017015J Page 1 of 1

834-203644 Rev.B

305265/A 37

Simrad 38-9

Mounting arrangement

Air outlet

Steel blister, to be
manufactured by the
installation shipyard
(Simrad dwg 830-203430)

Mounting ring, may
be supplied by Simrad
(Simrad dwg 499-203337)

FORWARD

Self-locking
threads

WARNING: lift the
transducer by the cable!

Note:
All measurements are in mm.
The drawing is not in scale.

Do not

Washer

Bolt M10x100
Maximum torque 31 Nm!

CD017015K Page 1 of 2

820-203666 Rev.A

38 305265/A

Recommended transducer location

Approx 3 deg

Air/water outlet
(optional) near
the echo sounder,
above water level

Minimum
400 mm

Drawing file

X

Min. X/4

ø35

Steel conduit

ø65

Stuffing tube

Washer
Rubber gasket
Washer
Packing nipple

Service loop
on cable

Note:
All measurements are in mm.
The drawing is not in scale.

Steel conduit:

Recommended to minimize electrical interference.
Minimum inside diameter: 35 mm
Wall thickness: 6 mm (or 4.5 mm if galvanized
conduit is used)

Minimum
400 mm

CD017015K Page 2 of 2

820-203666 Rev.A

305265/A 39

Simrad 38-9

Mounting ring

Surface treatment:

1) Sand blast to SA 2.5

2) One coating of red ferric oxide primer

310

The self-lock threads (SL*) must be made in
accordance with Simrad procedure 842-202125.
Self-lock taps can be supplied by Simrad.

30°

60°

M10 SL* (x6)

Ø0.2

Note:
All measurements are in mm.
The drawing is not in scale.

CD017015G Page 1 of 2

871-203337 Rev.B

40 305265/A

Material: St 52-3N (DIN 17100) Round steel or plate

125 ±1

Drawing file

14 ±2

ø155 ±1

21 ±1

100 +0/-0.5

45°

ø342 +0.5/-0

6.3

ø348 ±1

ø360 ±1

Chamfer
3 x 45°

Note:
All measurements are in mm.
The drawing is not in scale.

305265/A

R1 (max)

CD017015G Page 2 of 2

871-203337 Rev.B

41

Simrad 38-9

Blister assembly

Surface treatment:

To avoid acoustic noise, it is very important that the surface of the blister is
smooth. Avoid cracks, dents and other unevenness.

1) Sand blast after grinding to SA 2.5

2) Apply one coat of red ferric oxide prime

3) No concavity is accepted

4) Maximum convexity is 3 mm

5) Small local hollows (max 1 mm!) can be accepted

510

347

Drainage hole

Ø10 to 15 mm

(A) (A)

30°

Steel blister
Stiffening ribs
Mounting ring

602

1420

Note:
All measurements are in mm.
The drawing is not in scale.

42

CD017015H Page 1 of 2

830-203430 Rev.B

305265/A

Air vent holes
R25 to 50 mm

Drawing file

(B)

100

(A - A)

(B)

(B-B)

Depends on

dead rise

Minimum
400 mm

243

Note:
All measurements are in mm.
The drawing is not in scale.

305265/A 43

CD017015H Page 2 of 2

830-203430 Rev.B

Simrad 38-9

Blister design

Bottom plate must be smooth and even!

1) No concavity is accepted

2) Maximum convexity is 3 mm

3) Small local hollows (max 1 mm!) can be accepted

15°

10°

30°

23°

(A) (A)

R1030

R10

R1740

(486)

R1740

45°

R525

R150

5°

602

1420

Note:
All measurements are in mm.
The drawing is not in scale.

44

CD017015I Page 1 of 2

871-203432 Rev.A

305265/A

Materials: Steel plate, Fe 510 D1 (St 52-3 N), 6 and 10 mm

(B)

(A - A)

(B)

Drawing file

10

66

Height

depends

on dead

rise

R10

Note:
All measurements are in mm.
The drawing is not in scale.

(B-B)

Minimum
400 mm

CD017015I Page 2 of 2

871-203432 Rev.A

305265/A 45

Simrad 38-9

A

Acoustic window

installation, 21
Air bubbles, 6
Anti-fouling

paint, 34
Arctic tank

cleaning, 33

painting, 33

polycarbonate, 33

B

Blister

installation, 11
Blister assembly

drawing, 42
Blister design

drawing, 44
Boundary

water layer, 7
Bow thrusters

noise, 8
Box keel

installation, 17

C

Cable

Single beam transducer, 36

splicing, 31
Cable gland

GRP hull, 29

small hull, 30

steel hull, 28
Cavitation, 6
Clamping ring

acoustic window, 21

blister, 11

box keel, 17

flush mounting, 19

inside hull, 23
Conduit, 32
Connection

single beam transducer, 36

D

Depth, 6
Drawing

Blister assembly, 42

Blister design, 44

Mounting arrangement, 38

Mounting ring, 40

Outline dimensions, 37
Drawing file, 35

E

EMC interference, 32

F

Flush mounting

flush mounting, 19

G

GPT Connection

single beam transducer, 36

GRP hull

cable gland, 29

H

Handling, 33
Heave

vessel, 6

I

Inclination

angle, 8

Installation

drawings, 35

L

Layer

boundary, 7

Location

recommendation, 8
transducer, 6

M

Maintenance, 33
Mounting arrangement

drawing, 38

Mounting ring

acoustic window, 21
blister, 11
box keel, 17
drawing, 40
flush mounting, 19
inside hull, 23

N

Noise

air bubbles, 6
bow thrusters, 8
cavitation, 6
propeller, 7

protruding objects, 6

O

Outline dimensions

drawing, 37

P

Paint

anti-fouling, 34

Propeller

noise, 7

Protruding objects, 6

S

Single beam transducer

connection, 36

Splicing

cable, 31
Steel conduit, 32
Steel hull

cable gland, 28
Steel tank

flush mounting, 19
Support bar

acoustic window, 21

blister, 11

box keel, 17

flush mounting, 19

inside hull, 23
Surface

acoustic window, 21

blister, 11

box keel, 17

flush mounting, 19

inside hull, 23

T

Transducer

depth, 6

location, 6

recommended location, 8
Transducer cable

splicing, 31

V

Vessel

heave, 6

W

Water filled

flush mounting, 19

46 305265/A

ISBN-10: 82-8066-074-7

ISBN-13: 978-82-8066-074-9

©

2006 Simrad

Simrad Horten AS

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

Telephone:[phone]
Telefax:[phone]

www.simrad.com

[e-mail]