Simrad ST90 - Noise Sources; Dry Docking Requirements; Requirement for Classification Approval

442703/B
49
Noisesources
TheoperationalperformanceoftheST90Fishndingsonardependsonthenoise
conditions.Itisessentialthatthenoisesignatureisaslowaspossible.
Thevessel’shull,rudder(s)andpropeller(s)mustbethoroughlyinspectedindrydock
priortoinstallation.
Roughnessbelowthewater-linedeformitiesintheshellplatingandprotrudingobstacles
cancreateunderwaternoise.Thesesourcesofturbulencemustbesmoothedorremoved
asbestaspossible.
Note
Itisespeciallyimportantthatthepropeller(s)arenotpittedordamaged.
Relatedtopics
Installationrequirements,page47
Drydockingrequirements
Wheneverahullunitandaninstallationtrunkaremountedunderthevessel’shull,
specialconsiderationsmustbemadepriortodrydocking.
MakesurethatampleclearanceundertheST90installationtrunkand/orblisteris
providedwhenyouareplacingthevesselindrydock.Avoidlocatingsupportingblocks
orstructuresinthevicinityoftheST90installationtrunk.
Priortodrydocking,powerdowntheST90.Disengagethecircuitbreakerifnecessary.
LabeltheProcessorUnitand/orthecircuitbreakerclearlytopreventanyonefrom
poweringuptheST90accidentally.
Note
ThelocationoftheST90installationtrunkmustbenotedonthevessel’ sdockingplan
forfuturereference.
Relatedtopics
Installationrequirements,page47
Requirementforclassicationapproval
ClassicationapprovalisrequiredfortheST90installation.
TheST90sonartrunkinstallationmustbeapprovedbyDNVGLoranothernational
classicationsociety.Theshipownerandshipyardperformingtheinstallationare
responsibleforobtainingtheclassicationapproval.
SimradST90