MCT Brattberg “RGS Single or Multiple Cable Rectangular Transits”, for use in approved A Class steel and aluminium bulkheads and/or decks and in Non-load bearing A-60 Sandwich Panel Bulkheads, as described in the attached DAD. (MCT Brattberg “RGS Single or Multiple Cable Rectangular Transits”)

Common issues

• Incorrect insert/module selection for the actual cable diameter, leaving gaps in the fire seal
• Cables added or removed after installation without re-validating against the transit's approved cable schedule (DAD)
• Deteriorated or missing frame gasket compromising fire/gas-tight integrity
• Under- or over-compression of insert modules from incorrect wedge/bolt torque
• Corrosion of the steel/aluminium frame at the bulkhead or deck penetration
• Unsealed spare/blank modules left in an otherwise sealed frame

Inspection checklist

• Visually check insert modules for cracking, displacement, or missing pieces
• Confirm the installed cable count/diameters match the transit's approved Design Appraisal Document (DAD)
• Check frame gasket condition and compression at the bulkhead/deck interface
• Verify wedge/tensioning bolts are torqued per maker's instruction
• Check for corrosion at the frame-to-structure weld or bolted connection
• Confirm blank modules are fitted and sealed where no cable is present
• Check for any unauthorised cable additions since the last survey

Service intervals

Critical spares

• Blank/spare insert modules matching the frame's module size
• Frame gasket
• Wedge/tensioning bolt set

Safety

• An incorrectly filled or damaged transit compromises the fire (and sometimes watertight/gastight) integrity of the A-class division it penetrates
• Unauthorised cable additions without re-sealing are a recognised source of fire integrity failures found at survey
• Work on the transit should be coordinated with a hot-work/fire watch procedure if adjacent to flammable spaces

Class survey

Cable transits through A-class divisions are checked against their type-approval certificate and the vessel's Design Appraisal Document (DAD) at fire safety surveys; any cable added after the original installation must be verified against the approved schedule or the transit's fire rating cannot be assumed valid.