During repairs it is necessary to replace existing vessel bulkhead. Drawings indicate the bulkhead is A60. "A" indicates which of the following?

Correct Answer: Option D — "A" class bulkheads must not allow flame or smoke passage for 60 minutes when subjected to a fire test

Under SOLAS and USCG structural fire protection standards, 'A' class bulkheads must be constructed of steel and capable of preventing the passage of smoke and flame for a full 60 minutes when subjected to the standard cellulosic fire test.