Simrad ST90 - Lowering and Hoisting Transducer (Sonar Room)

442703/B
119
5Placethetrunkextendercarefullyontopoftheexistingtrunk,andmountitwith
thebolts.
Usethecorrecttorque:470Nm
6Bracetheinstallationtrunktothehullplatingandthesurroundinghullframes
byaddingseveralstrengtheningplates.
Theplatesmustbeatleast1.5timesasthickasthesurroundingshellplating.The
naldimensionsofthedoublingplatemustbedenedintheapprovedinstallation
drawingssuppliedbytheshipyard.
Relatedtopics
Mountingtheinstallationtrunk,page109
Installationtrunkmountingoverview,page110
439413Trunkextender(350mm),page439
374676Trunkextender(180mm),page442
Verifyingthequalityoftheinstallation
Oncetheinstallationtrunkandblisterhavebeeninstalled,aqualityinspectionmusttake
place.Thepurposeoftheinspectionistomakessurethattheinstallationtrunkhasbeen
installedcorrectly,andthatthehullunitcanbemountedontopofit.
Prerequisites
Neithertoolsnorinstrumentsarerequired.
Context
Theinstallationtrunkmustbemountedsothatitremainsverticalduringnormal
operatingconditions.
Thetopmatingsurfaceoftheinstallationtrunkmustbeprotectedwithablindangeor
woodencoveratalltimesuntilthehullunitisinstalled.Itisveryimportantthatthis
surfaceiscleanandundamaged,becauseitmustbewatertightafterthehullunithasbeen
installedontopoftheinstallationtrunk.
Objectsprotrudingfromthehullwillgenerateturbulenceandownoise.Thiswill
reducetheST90performance.Protrudingobjectsmaybezincanodes,transducersor
eventhevessel'skeel.Holesandpipeoutletsarealsoimportantnoisesources,aswellas
roughsurfacescausedbybadwelding.Eventracesofsealingcompound,sharpedges,
boltsoremptyboltholeswillcreatenoise.
Mountingtheinstallationtrunk