Kongsberg EM 2040P User manual

417418/B
December2017©KongsbergMaritimeAS
EM2040P
Multibeamechosounder
Installationmanual

KongsbergMaritimeAS
www.kongsberg.com
Documentinformation
•Product:KongsbergEM2040P
•Document:Installationmanual
•Documentnumber:417418
•Revision:B
•Dateofissue:December2017
Note
TheinformationcontainedinthisdocumentremainsthesolepropertyofKongsbergMaritimeAS.No
partofthisdocumentmaybecopiedorreproducedinanyformorbyanymeans,andtheinformation
containedwithinitisnottobecommunicatedtoathirdparty,withoutthepriorwrittenconsentof
KongsbergMaritimeAS.
KongsbergMaritimeASendeavourstoensurethatallinformationinthisdocumentiscorrectandfairly
stated,butdoesnotacceptliabilityforanyerrorsoromissions.
Warning
Theequipmenttowhichthismanualappliesmustonlybeusedforthepurposeforwhichitwas
designed.Improperuseormaintenancemaycausedamagetotheequipmentand/orinjurytopersonnel.
Youmustbefamiliarwiththecontentsoftheappropriatemanualsbeforeattemptingtooperate
orworkontheequipment.
KongsbergMaritimedisclaimsanyresponsibilityfordamageorinjurycausedbyimproperinstallation,
useormaintenanceoftheequipment.
Comments
Toassistusinmakingimprovementstotheproductandtothismanual,wewelcomecommentsand
constructivecriticism.
e-mail:[email protected]
Fortechnicalsupportissues,pleasecontact[email protected].
Supportinformation
Ifyourequiremaintenanceorrepair,contactyourlocaldealer.Youcanalsocontactususingthefollowing
address:[email protected].Ifyouneedinformationaboutourotherproducts,
visithttp://www.km.kongsberg.com

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Tableofcontents
ABOUTTHISMANUAL..............................................................7
EM2040P................................................................................9
Systemdescription.............................................................................................................9
Systemdiagram................................................................................................................10
Systemunits.....................................................................................................................11
Transducerdescription...........................................................................................11
ProcessingUnitdescription....................................................................................11
PortableProcessingUnitdescription.....................................................................11
HydrographicWorkStationdescription.................................................................12
RuggedHydrographicWorkStationdescription...................................................12
RemoteControlUnit(K-Rem)description............................................................12
PREPARATIONS.....................................................................14
Personnelqualications...................................................................................................14
Sonarroomrequirements.................................................................................................15
Environmentalrequirements..................................................................................15
Requirementforwatertightintegrity......................................................................15
Sizeandaccessrequirements.................................................................................16
Requirementsforinsulation,heatingandventilation.............................................16
Requirementsforelectricalinstallations,cablesandcommunication...................17
Requirementsforbilgepumpanddecking.............................................................18
Wheretoinstallthetransducer........................................................................................19
Introductiontotransducerlocation.........................................................................19
Mountthetransducerdeep.....................................................................................19
Avoidprotrudingobjectsnearthetransducer.........................................................20
Keepthetransducerfarawayfromthepropellers.................................................21
Chooseatransducerpositionfarawayfromthebowthruster(s)...........................21
Summaryandgeneralrecommendations...............................................................21
Acousticnoise..................................................................................................................23
Contributingfactors................................................................................................23
Selfnoise................................................................................................................24
Ambientnoise.........................................................................................................27
Electricalselfnoise................................................................................................27
Somemeanstoreduceacousticnoise....................................................................27
Vesselcoordinatesystem.................................................................................................29
INSTALLINGTHETRANSDUCER.............................................32
Rulesfortransducerhandling..........................................................................................32
Installationsummary........................................................................................................34
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Installationrequirements..................................................................................................36
Freeviewingsector................................................................................................36
Installationprinciples.......................................................................................................37
Permanenttransducerinstallation..........................................................................37
Nonpermanenttransducerinstallation...................................................................38
Transducerinstallationusingahullunit................................................................39
ReferencepointontheEM2040Ptransducer.................................................................40
Paintingthetransducerface.............................................................................................41
Approvedanti-foulingpaints...........................................................................................43
INSTALLINGTHEEM2040PHARDWAREUNITS.....................44
InstallingtheProcessingUnit..........................................................................................45
InstallingtheProcessingUnit.................................................................................45
ProcessingUnitrearpaneldescription...................................................................47
ProcessingUnitcircuitboardsandmodules..........................................................48
CBMFboard-dipswitchsetting...........................................................................49
InstallingthePortableProcessingUnit............................................................................50
PortableProcessingUnitdescription.....................................................................50
PortableProcessingUnitfrontpaneldescription..................................................51
InstallingtheHydrographicWorkStation.......................................................................52
InstallingtheHydrographicWorkStation..............................................................52
HydrographicWorkStationrearconnectors(MP5810)........................................55
CABLELAYOUTANDINTERCONNECTIONS.............................57
Readthisrst...................................................................................................................58
Cableplans.......................................................................................................................59
ProcessingUnit,singleswath,cableplan..............................................................60
ProcessingUnit,dualswath,cableplan.................................................................61
PortableProcessingUnit,cableplan......................................................................62
Topsidecableplan..................................................................................................63
ListofEM2040Pcables..................................................................................................64
Cabledrawingsandspecications...................................................................................66
RS-232seriallineusingthreewiresandRJ45connector......................................67
RS-422seriallineusingvewiresandRJ45connector........................................68
RS-232seriallineusedforDGNSSinput..............................................................69
RS-422seriallineusedforDGNSSinput..............................................................70
Clocksynchronisation(1PPS)usingacoaxcable.................................................71
Remotecontrol.......................................................................................................72
RemoteControlusingK-Rem................................................................................73
Dummyplugfornotusingremotecontrol.............................................................74
Externalsynchronisation........................................................................................75
Transducercable.....................................................................................................76
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TransducercableforPortableProcessingUnit......................................................78
Seapathantennainterfacecable-withplug...........................................................80
Antennainterfacecable..........................................................................................82
SeapathMRUinterfacecable.................................................................................83
DCPowercable......................................................................................................84
DRAWINGFILE......................................................................85
Transducerdimensions....................................................................................................86
Transducermountingbracket...........................................................................................87
385422ProcessingUnitdimensions................................................................................88
424178PortableProcessingUnitdimensions.................................................................89
378828HydrographicWorkStationdimensions.............................................................90
370275RemoteControlUnit(K-REM)dimensions.......................................................92
373962RemoteControlUnit(K-REM)wiringdiagram.................................................94
TECHNICALSPECIFICATIONS................................................95
Performancespecications..............................................................................................96
Interfacespecications.....................................................................................................97
Weightsandoutlinedimensions....................................................................................101
Powerrequirements.......................................................................................................102
Environmentalrequirements..........................................................................................104
Alignmentspecications................................................................................................105
EQUIPMENTHANDLING.......................................................107
TransportingKongsbergMaritimeequipment...............................................................108
Liftingunitsandtransportationboxes...........................................................................109
Inspectionofunitsandtransportationboxesafterarrival..............................................111
Specicationsforstoragepriortoinstallationoruse.....................................................112
Unpackinginstructions..................................................................................................114
Unpackingstandardpartsandunits......................................................................114
Unpackingmechanicalunits................................................................................115
Unpackingelectronicandelectromechanicalunits..............................................116
Unpackingtransducers.........................................................................................117
Specicationsforstorageafterunpacking.....................................................................119
GENERALSAFETYRULES.....................................................121
Generalsafetyrules........................................................................................................121
Installationmanual

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EM2040P

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Aboutthismanual
Purposeofmanual
Thepurposeofthismanualistoprovidetheinformation,proceduresandbasicdrawings
requiredforthephysicalinstallationoftheEM2040P.
Targetaudience
Themanualisintendedfortechnicalpersonnel;suchasskilledshipyardworkers,
electricians,qualiedengineersandnavalarchitects.Itisassumedthatyouunderstand
thegeneralprinciplesofmaritimeelectronicequipment.Y oumustalsobefamiliarwith
computerhardware,interfacetechnologyandinstallationofelectronicandmechanical
products.
Weassumethatyouarefamiliarwiththebasicacousticprinciplesofsoundinwater.
Wealsoexpectthatyouhavesomeexperiencewithmultibeamand/orsinglebeamecho
soundersinhydrographicapplications..
Installationinstructions
Youmustfollowtheinstructionsinthismanualtoensureoptimalperformance.Asa
guide,installationproceduresarepresentedintheordertheymustbedone.
Theequipmentdescribedinthismanualincludesthecompletesystemwithrelevant
cabinets.Unitsprovidedlocallybythecustomer,installationshipyardorlocal
representativearenotdescribed.
Themanualalsodenestheequipmentresponsibility,andprovidesapplicable
instructionsforunpackingandstorageofunits.
Note
Youmustfollowtheinstructionsgiveninthismanual.Ifnotitmayaffectthewarranty.
KongsbergMaritimeASwillacceptnoresponsibilityforanydamageorinjurytothe
system,vesselorpersonnelcausedbyequipmentthathasbeenincorrectlyinstalledor
maintained,orbydrawings,instructionsorproceduresthathavenotbeenprepared
byus.
Installationdrawings
Theinstallationshipyardmustprovideallnecessaryinstallationdrawings.
Aboutthismanual

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KongsbergMaritimeASmay,onspecialorder,provideassistancetothesedrawings.
Note
Ifrequired,alldocumentsprovidedbytheshipyardforthephysicalinstallationof
theEM2040Pmustbeapprovedbythevessel’ snationalregistryandcorresponding
maritimeauthorityand/orclassicationsociety.Suchapprovalmustbeobtainedbefore
theinstallationcanbegin.Theshipownerandshipyarddoingtheinstallationare
responsibleforobtainingandpayingforsuchapproval.
TheoutlinedimensionsoftheEM2040PunitsarefoundintheDrawinglechapter
inthismanual.
Onlineinformation
ForinformationabouttheEM2040PandotherproductsfromKongsbergMaritime,
visitourwebsite.
•https://www.km.kongsberg.com
Registeredtrademarks
Observetheregisteredtrademarksthatapply.
Windows®isaregisteredtrademarkofMicrosoftCorporationintheUnitedStatesand
othercountries.
EM®isaregisteredtrademarkofKongsbergMaritimeASinNorwayandothercountries.
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EM2040P
Topics
Systemdescription,page9
Systemdiagram,page10
Systemunits,page11
Systemdescription
TheEM2040Portableisatruewidebandhighresolutionshallowwatermultibeamecho
sounder.Itisanidealtoolforanyhighresolutionmappingandinspectionapplication.
EM2040PisbasedontheEM2040technology.Thereceiverandtransmitterare
integratedinacommonsonarhead.
Keyfeatures
•Frequencyrangefrom200to400kHz
•Highresolution
•Dualswathoption,allowingsufcientsounddensityalongtrackatreasonablesur-
veyspeed
•FMchirpallowingmuchlongerrangecapability(depthandcoverage)com-
paredtoCWpulses
•Completeroll,pitchandyawstabilization
•Neareldfocusingonbothtransmitandreceive
•Shortpulselengths,largebandwidth.Shortestpulseis14μs
•IHO-S44specialordercompliant
•Seabedimage
•Watercolumnloggingasanoption
•Swathcoverage:140degrees
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•Beamwidth:1x1degreeat400kHz
•Transducerdepthrating:30metres
•Easytoinstall
Systemdiagram
ThesystemdiagramidentiesthemaincomponentsofabasicEM2040Psystem.Only
themainconnectionsbetweentheunitsareshown.Detailedinterfacecapabilitiesand
powercablesarenotshown.
AHydrographicWorkStation
BInterfaces:
•Soundspeedsensor
•Tide
•Centredepthoutput
CProcessingUnit
DInterfaces:
•Positioningsystems
•Attitude(roll,pitchand
heave)
•Soundspeedsensor
–WithK-Controller
upgrade
•Velocity
•Heading
•Clock
•Triggerinput/output
•Clocksynchronisation
(1PPS)
ETransducer
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Systemunits
Transducerdescription
Atransducerisadevicethatconvertsoneformofenergytoanother.Inanechosounder
systemthetransducerconvertsbetweenelectricenergyandsound.TheEM2040Phas
transducersfortransmittingandreceivingsoundpulsesinonehousing,andwecallthis
housinga"sonarhead".
Asinglecablewithanunderwaterplug,connectsthe
transducertotheProcessingUnit.
TheEM2040Ptransducerhasseparatelinear
transducerarraysfortransmitandreceiveinaMills
crossconguration.Thetransducercontainsallanalog
electronicsanddigitalcontrolunitswithEthernet
interfacetotheProcessingUnit.Thetransmitteriselectronicallysteerablealongtrack
whilethereceiverissteerableathwartship.
Thetransmittransducerconsistsofthreeseparatelinearrays,onelookingstraightdown
andthetwootherspointing45degreestoeachside.
Thetransducersaremadefromcompositeceramicswhichenablesawidebandwidth.
Thematerialinthepartofthetransducerhousingwhichisexposedtoseawaterishard
anodisedaluminium.
ProcessingUnitdescription
TheProcessingUnitisthecentralcontrollingdeviceintheEMmultibeamsystem.Itis
providedtoprocessthesignalstoandfromthetransducer(s).
Itisanindustrialcomputerwhichisdesignedand
testedforruggeduse.
TheProcessingUnitalsosupplies48Vdcpowertothe
transducer(s).
PortableProcessingUnitdescription
TheEM2040PProcessingUnitisavailableinaportableversion.
Theportableversionhasthesamefunctionalityasthe
standardEMProcessingUnitinarugged,splashproof
enclosure.Italsosupportsasinglecableinterfaceto
theSeapath130Series.
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HydrographicWorkStationdescription
TheHydrographicWorkStationistheoperatorstationfortheEM2040P.
Adedicatedmaritimecomputerisprovidedwiththe
EM2040PMultibeamechosounder.Itissetupwith
allnecessarysoftware.
TheHydrographicWorkStationisbasedonthe
Microsoft®Windowsoperatingsystem.
TheHydrographicWorkStationisnormallymounted
neartheoperatorworkspace.
RuggedHydrographicWorkStationdescription
TheHydrographicWorkStationistheoperatorstationfortheEM2040P.
Adedicatedmaritimecomputerisprovidedwiththe
EM2040PMultibeamechosounder.Itissetupwith
allnecessarysoftware.
TheHydrographicWorkStationisalsoavailablein
asemiruggedorfullyruggedversionforportableuse.
RemoteControlUnit(K-Rem)description
Adedicatedjunctionboxhasbeendesignedtoprovideremoteon/offswitcheswithlight
indicationandinterfacetoaremotesynchronizingsystem.Thejunctionboxcontainsa
terminalblockandfourswitcheswithlampsmountedinthefront.
Note
TheRemoteControlUnitisnotastandardpartof
theEM2040Pdelivery.
TheRemoteControlUnitiscalledK-Rem.Itis
preparedforremotecontrolandinterfacetoanexternal
synchronizationsystemforfourKongsbergechosounders.
•OneSub-bottomproler(SBP120orSBP300)
•TwoEMmultibeamechosounders
•OneEAsinglebeamechosounder
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TheRemoteControlUnitisdesignedtobemountedina19inchrack,butitisalso
possibletomountitonaatsurfaceorinabulkhead.Itisalsopreparedformounting
ontelescopicrails.
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Preparations
Topics
Personnelqualications,page14
Sonarroomrequirements,page15
Wheretoinstallthetransducer,page19
Acousticnoise,page23
Vesselcoordinatesystem,page29
Personnelqualications
TheinstallationoftheEM2040Pisademandingtask.Itisveryimportantthatthe
personnelinvolvedintheinstallationtasksarecompetentandexperiencedcraftsmen.
Asaminimum,thefollowingcertiedcraftsmenmustbeavailable.
•Navalarchitects
•Welders
•Electricians
•Projectmanager
Note
Thequalityoftheweldingiscriticaltothesafetyofthevessel.Weldingmustonlybe
donebyacertiedwelder .
Ifapplicable,thenalinstallationweldsmustbeapprovedbythevessel’ snational
registry,thecorrespondingmaritimeauthorityand/orclassicationsociety.Observethe
relevantrulesandregulationsrelatedtowelding.
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Sonarroomrequirements
Topics
Environmentalrequirements,page15
Requirementforwatertightintegrity,page15
Sizeandaccessrequirements,page16
Requirementsforinsulation,heatingandventilation,page16
Requirementsforelectricalinstallations,cablesandcommunication,page17
Requirementsforbilgepumpanddecking,page18
Environmentalrequirements
TheEM2040Punitsmustbeinstalledinadryanddust-freeenvironment.Theunits
arenotfullyprotectedagainsthumidity,dustorwater.
Itisimportantthatthesonarroomiskeptdry.TheEM2040Punitsmustnotbeexposed
toexcessivetemperatures,moistureorhumidity.Suchconditionscancausecorrosive
attacksandsubsequentfailurestotheelectroniccircuitry.Visitthesonarroomat
regularintervalstochecktemperatureandhumidity,andtakethenecessaryactions
iftheenvironmentalconditionsarepoor.
ObservetheenvironmentalspecicationsrelatedtotheEM2040Punits.
Requirementforwatertightintegrity
Thesize,locationanddesignofthesonarroommustfullalltherequirementstothe
vessel’swatertightintegrity.
Intheeventofamajorleakinthesonarroom,itmustbepossibletocloseallwatertight
hatchesand/ordoorstothesonarroomtomaintainthevesselstabilityandsafety.
Thephysicalsizeofthesonarroommustbelimited,sothatintheeventofamajor
leak,theoodingofthesonarroomwillnotinduceinstability,orcausethevesselto
capsizeorsink.
Ensurethatallwatertightdecksandbulkheadsareinspectedperiodicallytoverifythat
therearenounprotectedopeningsorimproperpenetrationsthatwillallowprogressive
oodingfromthesonarroom,andthatthewatertightdoorsandhatchesareinplaceand
inworkingorder.
Ensurebilgehighlevelalarmsarearrangedtoprovidetheearliestwarningsofabnormal
accumulation.Thehighlevelbilgealarmsmustbesetaslowaspossibletothedeck
orbilgewellandpositionedalongthecentreareaofthecompartmentorinalocation
atwhichtheuidswillgravitatetorst.
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Allcablesleadinginandoutofthesonarroommustberuninsteelconduits.Thesesteel
conduitsmustreachupandabovethefreeboarddeck.
Sizeandaccessrequirements
Awelldesignedsonarroomwithawellttedsizeandeasyaccessreducestheriskof
corrosion,andsimpliesmaintenance.Thisincreasessystemreliability.
Note
Thephysicalsizeofthesonarroommustbelimited,sothatintheeventofamajorleak,
theoodingoftheroomwillnotinduceinstability,orcausethevesseltocapsizeorsink.
Thesonarroommustbelargeenoughtohouseallthesystemunits.Theroommust
provideenoughspacetoallowefcientmaintenance.Y oumustbeabletokeepallthe
cabinetdoorsfullyopenwithoutunduerestrictiontoyourmovements.
1Theroommustnotbeusedforanyotherheavymachinery.
2Theroommustnotbeunnecessarilyobstructedbygirders,pipesetc,whichmay
causeinstallationproblemsorimpedemaintenance.
3Theroommustbeaccessibleunderallconditionsatseaorataberth.
4Alldoorsorhatchesmustbedesignedsothatthetoolsandequipmentcanbe
removedwithoutbeingdisassembled.
5Allcablesleadinginandoutofthesonarroommustberuninsteelconduits.These
steelconduitsmustreachupandabovethefreeboarddeck.
Requirementsforinsulation,heatingandventilation
Thebulkheadsinthesonarroommustbeinsulatedandprovidedwithaninteriorwall
tothedeck.Theroommustbeequippedwithheater,anditmustbeconnectedtothe
vessel'sventilationsystem.
Insulationrequirements
Theinsulationinthesonarroomshouldbetheminimumequivalentof50mmof
rock-wool.Pipingpassingthroughthespacepronetocondensationmustbeproperly
insulated.
Heatingrequirements
Heatingisaneffectivemethodforreducinghumidity.Theheaterinthesonarroommust
dimensionedtomaintaintheequipmentwithinitsenvironmentaltolerances.Typical
heatingpowerisminimum1000W.Theheatermustbeinstalledclosetothedeck.
EM2040PInstallationmanual

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Ventilationrequirements
Thesonarroommustbeconnectedtothevessel'sventilationsystemtoensureasupply
ofcoolingair.Ifaventilationsystemisnotavailable,installtwo3”pipesfromthesonar
roomtoasuitablefreshairlocationondeck.
Thefreshairshouldentertheroomasclosetotheooraspossible,andshouldbe
extractedfromashighaspossible.Afunnelshapeddrip-collectormustbemounted
belowtheventpipestodivertmoisturetothebilge.Onthemaindeck,thebest
ventilationisprovidedwhentheoutletpipeisatleastfourmetershigherthantheinlet
pipe.Tokeepoutseawater,rainandspray,theventilationpipesmustbettedwith
goosenecksoranequivalentdesign.
Note
Ifthevesselislikelytooperateintropicalconditions,asuitableairconditioningsystem
mustbeinstalled.Theairconditioningsystemmustbeabletoprovideanambient
temperaturethatdoesnotexceedthemaximumoperatingtemperaturesoftheEM2040P
unitsthatareinstalledintheroom.
Requirementsforelectricalinstallations,cablesand
communication
Theelectricalinstallationsinthesonarroommustmeetminimumrequirementsto
providesuitablelightsandsupplypower.
Lightrequirements
Thesonarroommustbeequippedwithsuitablelightingtosimplifytheinstallation
andtoaidfuturemaintenance.
Communicationrequirements
Thesonarroommustbeequippedwithatelephone,anintercomsystem,oranyother
meansoforalcommunicationbetweenthesonarroomandthebridgeand/orcontrol
room(s).
Powerrequirements
Eachunitinthesonarroomshouldbeprovidedwithaseparatecircuitbreakeronthe
mainssupply.
Aminimumnumberofadditionalelectricaloutletsmustbeprovidedforotherequipment.
Propervesselgroundmustbeprovided.
Cablingrequirements
ThesonarroomunitsareconnectedtootherEM2040Punitslocatedindifferent
compartmentsonthevessel.Theunitsmayalsobeconnectedtoperipheraldevices.If
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thesecablespassthroughhatchesorareaswheretheymaybedamaged,theymustbe
runinconduits.Minimum2”conduitisrecommended.
Makesurethatallsystemcablesareproperlyconnectedandsecured,andinstalled
withsomeslack.Theslackisessentialtowithstandvibrations,andtofacilitatefuture
maintenanceandreplacements.
Requirementsforbilgepumpanddecking
Ifthesonarroomislocatedbelowthewaterline,itmustbeconnectedtothevessel's
bilgepumpsystem.
Bilgepumprequirement
Ifitisnotpossibletoconnectthesonarroomtothevessel'sbilgepumpsystem,a
separatebilgepumpforthecompartmentmustbeinstalled.
Deckingrequirement
Oncetheinstallationhasbeencompleted,thesonarroommustbesuitablydecked
withoutrestrictingaccesstotheequipmentandthecables.
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Wheretoinstallthetransducer
Topics
Introductiontotransducerlocation,page19
Mountthetransducerdeep,page19
Avoidprotrudingobjectsnearthetransducer,page20
Keepthetransducerfarawayfromthepropellers,page21
Chooseatransducerpositionfarawayfromthebowthruster(s),page21
Summaryandgeneralrecommendations,page21
Introductiontotransducerlocation
Asingleanswertothequestion"wheretoinstallthetransducer"cannotbegiven.
Thephysicallocationofthetransducerdependsonthevessel'sdesignandconstruction,
howthehullisshaped,andhowthewaterrunsalongthehull.Therearehowevera
numberofimportantguidelines,andsomeoftheseareevenconicting.
Note
Theinformationheremustbeconsideredasgeneraladvice.EachEM2040Pinstallation
mustbehandledseparatelydependingonthehulldesignandtheotherelectricaland
mechanicalsystemsinstalledonthevessel.
Mountthetransducerdeep
InordertoachievethebestpossibleEM2040Pperformance,mountthetransduceras
deepaspossibleunderthevessel’shull.
Thereareseveralreasonsforthisrecommendation.
Flownoise
Considerthesituationswhenthevesselisunloaded,andpitchinginheavyseas.The
vesselisridinghigh,andthebowmayevenbeliftedoutofthewater.Thiswillcausea
lotofairtofollowtheshapeofthehull.
Theupperwaterlayersoftheseacontainamyriadofsmallairbubblescreatedbythe
breakingwaves.Inheavyseastheupper5to10metresmaybelledwithair,andthe
highestconcentrationswillbenearthesurface.Airbubblesabsorbandreectthesound
energy,andtheymayinworstcasesblockthesoundtransmissionaltogether.
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Cavitation
Cavitationistheformationofsmallairbubblesclosetothetransducerface.Thebubbles
appearbecausethelocalpressurebecomesnegativeduringpartsoftheacousticpressure
cycles.Thecavitationthresholdincreaseswiththehydrostaticpressure.Thenoiseis
madewhenthebubblesimplode.
Transmittinginair
Thetransducermustneverbeliftedfreeofthewatersurface.Ifthetransduceris
activatedwhenoutofwateritmaybedamagedbeyondrepair.Mountingthetransducer
atadeeppositiononthehullwillinnormallypreventthis.
Slamming
Slamminghappensifthevesselhullclimbsoutofthewaterinheavyseas.Theforceof
thewaterwhenthehullfallsdownmaypushthetransducerup,andmaycausedamage
bothtothetransducerandtoitsmounting.Thisisespeciallyimportantforlowfrequency
transducerswithlargefaces.Theeffectofslammingcanbereducedbymountingthe
transducerasdeepaspossibleonthehull.
Note
KongsbergMaritimeAStakesnoresponsibilityforanydamagestothetransducer,the
cableorthemountingarrangement,causedbyslamming.
Avoidprotrudingobjectsnearthetransducer
Objectsprotrudingfromthehullwillgenerateturbulenceandownoise.Thiswill
reducetheEM2040Pperformance.
Protrudingobjectsmaybezincanodes,transducersoreventhevessel'skeel.Holesand
pipeoutletsarealsoimportantnoisesources,aswellasroughsurfacescausedbybad
welding.Eventracesofsealingcompound,sharpedges,boltsoremptyboltholeswill
createnoise.Alltheseprotrudingobjectsmayactasresonantcavitiesamplifyingthe
ownoiseatcertainfrequencies.
Donotplaceatransducerinthevicinityofprotrudingobjects,andespeciallynotclose
behindthem.Makesurethatthesurfaceofthetransducerface,thehullplatingandputty
aroundthetransducerisasevenandsmoothaspossible.Mountingscrewsorboltsmust
notbeextrudingfromthetransducer,theinstallationhardwareorthehullplating.If
necessary,grindandpolishallsurfaces.
EM2040PInstallationmanual