A60 A30 B15 and B0 Marine Fire Door Ratings Explained

The A60 test in one sentence

A60 means the insulation withstands a 60 minute fire on one side while the unexposed side stays within 150 degrees Celsius above the starting temperature. That is a measured performance, not a description. A30 is the same test at 30 minutes. Those are A class divisions, which are the structural fire boundaries on the fire control plan.

B class is a different requirement

B15 and B0 are B class divisions. They are the boundaries between cabins and along accommodation alleyways rather than the main structural fire boundaries. They do not carry the insulation an A class division does, and they do not need to.

Why the correct rating matters more than the highest one

Fitting A60 doors where the fire control plan calls for B15 adds weight and cost to every opening in the accommodation block, and it adds it to the doors the crew opens most. The fire control plan already says which opening needs which rating. Follow it exactly.

Keeping the hardware common

The practical objection to using four ratings in one block is spares and fitting: four door types, four sets of hinges, four handle patterns. We build A60, A30, B15, B0 and C grades on common frame and hardware systems, so the yard fits them the same way and the vessel carries one set of spares.

Construction and installation

Marine fire doors are built in steel so they weld directly into the bulkhead structure. Leaf size and hand are made to each opening on your general arrangement, so what arrives is already correct for its position rather than a pallet of identical blanks. CCS, BV, LR, DNV, ABS and RINA certification is available.