3 Determination of Fire Suppression and Control Capablities
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Statutory Documents - IMO Publications and Documents - Circulars - Maritime Safety Committee - MSC.1/Circular.1272 – Guidelines for the Approval of Fixed Water-based Fire-fighting Systems for Ro-Ro Spaces and Special Category Spaces Equivalent to that Referred to in Resolution A.123(V) – (4 June 2008)1 - Annex – Guidelines for the Approval of Fixed Water-based Fire-fighting Systems for Ro-Ro Spaces and Special Category Spaces Equivalent to that Referred to in Resolution A.123(V) - Appendix – Test Method for Fixed Water–Based Fire-Fighting Systems for Ro-Ro Spaces and Special Category Spaces - 3 Determination of Fire Suppression and Control Capablities

3 Determination of Fire Suppression and Control Capablities

Parent topic: Appendix – Test Method for Fixed Water–Based Fire-Fighting Systems for Ro-Ro Spaces and Special Category Spaces

3.1 Principle

 These test procedures test the effectiveness of a water-based fire-fighting system against two different scenarios: a cargo fire in a simulated freight truck, and a passenger vehicle fire.

3.2 Fire source

  3.2.1 The primary fire source for both scenarios consists of EUR standard wood pallets (ISO 6780:2003), stored inside with the moisture content of 14 ± 2%. Figure 3.2.1 shows details of a EUR pallet.

  3.2.2 Plywood panels made of pine or spruce are used as targets. The panels should be approximately 12 mm thick. The ignition time of the panel should not be more than 35 s and the flame spread time at 350 mm position should not be more than 100 s as measured in accordance with resolution A.653(16).

  3.2.3 For ignition, commercial heptane is to be applied.

typical dimensions of the standard EUR pallet

3.3 Apparatus

3.3.1 Test area

 The tests should be conducted in a test hall as specified in paragraph 2.4 above, under a flat, smooth, non-combustible ceiling of at least 100 m2. There should be at least a 1 m space between the perimeters of the ceiling and any wall of the test hall.

3.3.2 Fire scenario 1: cargo fire in simulated freight truck (see figures 3.3.2.1 to 3.3.2.3)

  3.3.2.1 The primary fuel package consists of 112 wood pallets arranged in an array of 2 (wide) x 7 (high) x 8 (long) and raised up on a level of 2.8 m so that the top level of the fuel package is at 3.8 to 3.9 m above the floor.

  3.3.2.2 The support frame for the wood pallet array of paragraph 3.3.2.1 should be constructed using open steel racks. The wood pallet piles should be standing freely on horizontal steel beams without any solid bottoms.

  3.3.2.3 The fuel pallet array should be half-shielded by a 4.5 m long, 2.6 m wide steel plate (thickness at least 2 mm) at 4 m height. The plate should be properly fixed so that during a test it does not bend to provide an unobstructed passage of water onto the fuel package.

  3.3.2.4 Plywood panel targets (acting also as obstructions) of dimensions 3.6 m (wide) x 2.4 m (high) should be arranged symmetrically on both sides of the fuel package at 1 m distance so that the top edge is at the same level as the top level of the wood pallet array.

  3.3.2.5 The fire should be ignited by two steel trays centrally located under the fuel package as shown in figures 3.3.2.1 to 3.3.2.3. The square trays are 25 cm high and 0.1 m2 of free surface area. The trays should be filled with water and 1 l of heptane so that the free rim height above the liquid surface is 4 cm. The distance between the bottom of the wood pallet piles and liquid surface is 29 cm.

Side view of the cargo fuel package in a simulated truck

End View of the cargo fuel package in a simulated truck

Top view of teh cargo fuel package ina simulated truck

3.3.3 Fire scenario 2: passenger vehicle fire (see figures 3.3.3.1 and 3.3.3.2)

  3.3.3.1 The primary fuel package consists of 12 wood pallets arranged in an array of 1 pallet (wide) x 6 pallets (high) x 2 pallets (long) constructed inside a passenger vehicle mock-up.

  3.3.3.2 The passenger vehicle mock-up is constructed of nominally 2 mm steel.

  3.3.3.3 Plywood panel targets (acting also as obstructions) of dimensions 1.2 m (wide) x 1.75 m (high) should be arranged symmetrically on both sides of the mock-up at 0.6 m distance so that the top edge is at the same level as the top level of the mock-up car.

  3.3.3.4 The fire should be ignited by a steel tray centrally located under the fuel package as shown in figures 3.3.3.1 and 3.3.3.2. The square tray is 10 cm high and 0.1 m2 of free surface area. The tray should be filled with water and 1 l of heptane so that the free rim height above the liquid surface is 4 cm.

3.4 Nozzle positioning

 Nozzles should be installed in an array at the ceiling level in accordance with the manufacturer’s design and installation criteria. Tests should be repeated with three different relative locations between the nozzle array and the fuel package, i.e., centre of ignition under one nozzle, between two nozzles and between four nozzles, as shown in figure 3.4.1.

Side view of the passenger vehicle fuel package

 (The dashed lines visualize the shape of a car; the ceiling plate is to be fixed in its location as found most practical)

Top view of the passenger vehicle fuel package

Nozzle positioning in the two scenarios

3.5 Instrumentation

 Instrumentation for the continuous measuring and recording of test conditions should be employed. At least the following measurements should be made:

  • .1 gas temperature at 7.5 cm below the ceiling at locations shown in figure 3.5.1;

  • .2 gas temperature at the targets to indicate ignition of targets as shown in figure 3.5.2; and

  • .3 system water pressure near the centre of the piping array.

 System water flow rate should be defined with suitable means for the system.

Thermocouple locations in the two scenarios*

 * For the truck fuel package the three locations at both ends are used for acceptance evaluation, the three locations at and around the centre of ignition are for safety purposes to define during the test whether the ceiling is at danger. For the passenger car fuel package all four locations are used for acceptance evaluation.

Thermocouple locationsb at plywood targets for determining ignition of targets*

 *A thin (about 1 mm) steel sheet is bent on top of the plywood panels as shown in the figure. Plain charring of panels is seen as a sharp edge between the black charring on the exposed surface and intact surface under the metal sheet. When ignited in flames charring is seen also under the sheet and verified by significant increase in the gas temperature under the metal sheet.

3.6 Test programme and test procedure

3.6.1 Test programme

 Tests should be conducted at the minimum system water pressure at the minimum distance between the lowest part of the nozzles and the ceiling, as specified by the manufacturer.

 Three tests should be conducted at ceiling heights 5 m and/or 2.5 m, with different nozzle grid locations relative to the fuel package as specified in figure 3.4.1.

3.6.2 Test procedure

 Prior to starting the test the moisture content of the fuel package should be measured at several locations along the full package with a probe-type moisture meter and the results should be reported.

 The actual test procedure for all tests is as follows:

  • .1 the water pressure used at the start of the test should be set at the minimum value for the system specified by the manufacturer, flowing six open nozzles. If more than six nozzles operate during the test, the water supply pressure should be adjusted accordingly, to keep the required minimum system water pressure;

  • .2 the tray should be filled with 1llitre of heptane on the water base as described in paragraph 3.3.2.5 or 3.3.3.4;

  • .3 the measurements are started;

  • .4 the flammable liquid pool fire/s should be lit by means of a torch or a match;

  • .5 the fire should be allowed to burn freely for a period of 2.5 min;footnote

  • .6 the test is continued for 30 min after system activation;

  • .7 any remaining fire should be manually extinguished; and

  • .8 the test is terminated.

3.7 Acceptance criteria

 The principal acceptance criteria are based on the following factors:

  • .1 gas temperatures measured at locations not directly affected by impinging flames;

  • .2 damage to the fuel package; and/or

  • .3 ignition of targets.

  • Note 1: Damage to the fuel package is defined by the fraction of charring of the full package. The damage to each individual wood pallet should be evaluated separately and the total fraction calculated based on the detailed results. Totally black, i.e., totally charred pallet is denoted as 100% damage of the pallet (even though the pallet may have maintained its shape) and totally intact pallet is denoted as 0% damage. Partially charred pallets should be visually evaluated. Proper and adequate photographs of the damaged fuel package should be included in the test report.

  • Note 2: Ignition of targets is defined by the method described in figure 3.5.2, if the visibility during the test is such that it cannot be visually observed.

3.7.1 Fire scenario 1: cargo fire in a simulated freight truck (ceiling height 5 m)

 The following four criteria should be met:

  • .1 after system activation the maximum five minute average at any of the three measurement locations at the exposed end of the fuel package should not exceed 300oC;

  • .2 after system activation the maximum five minute average at any of the three measurement locations at the concealed end of the fuel package should not exceed 350oC;

  • .3 total damage to the wood pallet array should not exceed 45% as defined after the test; and

  • .4 the plywood targets should not ignite during the test.

3.7.2 Fire scenario 2: passenger vehicle fire

 The following two criteria should be met:

  • .1 after system activation the maximum five minute average at any of the four measurement locations should not exceed 350oC; and

  • .2 the plywood targets should not ignite during the test.

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