Fire Test Program to Verify the Calculation Method of Determining the A- 30 and A-15 Thickness of Approved Deck and Bulkhead Insulation Materials

摘要

The United States Coast Guard (USCG) required data to either support a proposal to the International Maritime Organization (IMO) or to change existing policy regarding structural insulation materials. Historically, the USCG has required testing of insulation materials at the thickness needed for use in a class A-6O assembly (i.e., expected to provide a minimum of 60 minutes of fire resistance). Upon successful completion of this testing, a calculation method was applied to determine the insulation thickness required for A-3O- and A-15-rated assemblies. The calculation method was 75 percent of the A-60 insulation thickness for an A-30 assembly, and 50 percent of the A-60 insulation thickness for an A-15 assembly. A series of bulkhead and deck fire tests was conducted to develop the required test data to evaluate the validity of this calculation method. Four bulkhead tests and four deck tests were conducted using the following materials: mineral fiber marine board, foil-faced mineral fiber, ceramic fiber, and spray-applied fiber. Each deck and bulkhead test assembly consisted of six test samples: two baseline thickness, two 75 percent of baseline thickness, and two 50 percent of baseline thickness. Each sample was 3 feet by 3 feet in size and did not contain stiffeners. Comparison of the test results with calculated times to exceed the temperature limits using the underlying heat transfer principles indicated that the calculation method is adequate and conservative. Heat transfer modeling of the tested assemblies was conducted to numerically reduce the thickness of each insulation material to fit as closely as possible the appropriate 60, 30, and 15 minutes of fire resistance requirements. Analysis of the reduced thicknesses using the heat transfer model has determined that the calculation method is adequate. (27 tables, 33 figures, 11 refs.).