Simrad ST90 - Page 119

442703/B
117
8Bracetheinstallationtrunktothehullplatingandthesurroundinghullframes
byaddingseveralstrengtheningplates.
Theplatesmustbeatleast1.5timesasthickasthesurroundingshellplating.The
naldimensionsofthedoublingplatemustbedenedintheapprovedinstallation
drawingssuppliedbytheshipyard.
9Stiffentheinstallationtrunkinboththefore-and-aftandathwartshipdirectionsby
weldingstrengtheningknee-platesbothtothetrunkandtothedoublingplate.
AStrengtheningknee-plates(stiffereners)
BInstallationtrunk
10Dependingontheshapeofthehull,werecommendthatyoutasteelblisterfor
protection.
Theblistermustbedesignedbytheinstallationshipyard.Itmustbeweldedto
theshellplating.Theblistermaybeanopentype,oritcanbelledwithoilto
preventcorrosion.Thislastmethodprovidesexcellentprotection,andsimplies
maintenance.
Note
Makesurethatthehullplatingsurroundingthetrunkisevenandsmoothwithout
protrudingobjectsthatcancausenoise.Objectsprotrudingfromthehullwill
generateturbulenceandownoise.ThiswillreducetheST90performance.If
necessary,grindandpolishallsurfaces.
11Assoonasallinstallation,weldingandgrindinghasbeendone,primeorpaintthe
trunkandthesurroundingareausingahighqualityprotectivecoating.
Note
Youmustalsoapplytheprotectivecoatingtotheinsideoftheinstallationtrunk.
12Inspecttheinstallationoftheinstallationtrunk,theblister,hullplatingandall
surfacesthoroughly.
Mountingtheinstallationtrunk