Fire testing of external combustible ship surfaces

Abstract

Reduced weight makes use of fiber reinforced polymer composite desirable in maritime construction applications. Exterior ship surfaces in combustible materials are although not covered by fire safety regulations and their fire protection is therefore a key issue. This paper reports how SP FIRE 105, a standardized test method for testing reaction to fire properties of façade systems, was adjusted and used to evaluate the potential for fire growth on external combustible ship surfaces; in particular fiber reinforced polymer composite surfaces protected with active or passive measures. The trials show that the test method is highly suitable but that some adjustments could be made to reduce uncertainties; in particular to use a gas burner instead of a heptane pool fire source and to add a strong criterion for when to activate active measures. Further efforts should also be made to develop suitable performance criteria, which were suggested to be based on the produced heat and the gas temperatures at the top of the panel.

A numerical comparison of protective measures against external fire spread

“…At the same time, 2 of the thermocouples in Figure closest to the fire source are seen to fail and pictures from the actual test show the Promatect boards on the lower part of the test rig hanging loose. Also, gaps between the plate thermometer and the Promatect cladding are visible at position C21, signalling on a high stress during the test . This may have caused changes around the flow field that affected the measurement in the test.…”

“…As a validation case of the numerical model, data retrieved from a large-scale fire test on a slightly altered SP FIRE 105 test rig were used. 19 In this particular test, 10-mm-thick non-combustible calcium silica boards (Promatect®) were attached on the facade, serving as a reference test in a series of experiments on the test rig. The purpose of these tests was to evaluate fire growth on external combustible ship surfaces with FRP instead of a regular building facade system.…”

“…To assess the panel surface, the thermal exposure was estimated by using a type of plate thermometers made of nominally 0.7-mmthick, 150-mm by 150-mm Inconel steel plates with wire thermocouples spot-welded on their backside. 19 The steel plates covered a hole with diameter Ø100 mm drilled through the panels for the thermocouple wires and the plates were attached flush to the surface with lightweight ceramic wool filling the cavity behind the plates. Type K thermocouples (Ø0.50-mm sheathed TCs) were used to measure the temperature in the buoyancy plume along the centreline of the panels.…”

“…Experimental setup, dimensions, and instrument positions (note that this is a slightly altered version of the standard test as the 2 window openings are missing and the instrumentation is changed)…”

“…The evaluation was done by performing a validation study of FDS against a large-scale fire test with a geometry as closely linked as possible to the setup used in the comparative analysis. The validation study of FDS was performed using experimental data 19 from a largescale fire test on a SP FIRE 105 test rig 20 at SP in Borås, Sweden. A description of the test rig setup and key results from this part is presented below.…”