4 Test Procedure

  4.1.1 Combination fire (paragraph 3.2.3.1 above): the 4 m² fire tray below the engine mock-up should be filled with at least 50 mm fuel on a water base with a freeboard of 150 ± 10 mm. The 3 m² fire tray on top of the engine should be filled with at least 50 mm fuel on a water base with a freeboard of 40 ± 10 mm (this requires that the notch on the side of the 3 m² fire tray is blocked off by an appropriate means, e.g., steel plate).

  4.1.2 Low pressure concealed fire and 0.1 m² tray fire (paragraph 3.2.3.3 above): the 0.1 m² tray should be filled with at least 50 mm fuel on a water base with a freeboard of 150 ± 10 mm.

  4.1.3 Flowing fire (paragraph 3.2.3.4 above): the 4 m² fire tray below the engine mock-up should be filled with a 50 mm water base and the 3 m² fire tray on top of the engine mock-up should be filled with a 40 mm water base. The fuel should be ignited when flowing down the side of the mock-up, approximately 1 m below the notch. The pre-burn time should be measured from the ignition of the fuel.

  4.1.4 Freshwater may be used for practical reasons if it is shown that seawater provides the same level of performance. This should be done either by repeating the freshwater test with the longest time to extinguishment with seawater to ensure that the minimum performance requirements are still fulfilled, or to use the small scale test method in appendix 4 to these Guidelines. If the system is tested in more than one test compartment, the seawater test should be performed in test compartment 2.

 The following should be measured during the test:

• .1 oil flow and pressure in the oil system;

• .2 foam concentrate flow and pressure, and water flow and pressure in the extinguishing system;

• .3 oxygen concentration in the test compartment. The sampling point should be located 4.5 m from the centre of the engine mock-up on the exhaust pipe side and 2.5 m from floor level (the measurement may be terminated when the foam fills up to the oxygen sampling point);

• .4 temperatures at the fire locations. Thermocouples should be located 1 m in front of the spray nozzles and 0.5 m above the tray fuel surface, to provide additional information about time to extinguishment;

• .5 temperatures at the inside air foam generators. Thermocouples should be located to measure the air temperature at the foam generator air inlet, 0.1 m to 0.2 m behind the water/premix nozzles;

• .6 foam solution pressure at the inlet to one of the foam generators; and

• .7 air supply pressure at the inlet to one of the foam generators for outside air systems.

 After ignition of all fuel sources, a 2 min pre-burn time is required for the tray fires, and 15 s for the spray fires and flowing heptane fires before the extinguishing agent is discharged.

 The overall time to extinction should not exceed 15 min. The oil spray and heptane, if used should be shut off 15 s after the fire has been judged extinguished. The foam system should be operated for a minimum of 1 min after fire extinguishment.

 Temperature of the test room, fuel and the simulated engine should be measured and recorded.

 The following observations should be recorded:

• .1 start of ignition procedure;

• .2 start of the test (ignition);

• .3 time when the system is activated;

• .4 time when inside air foam generators begin producing foam;

• .5 foam transit time from outside air generators to the delivery duct outlets;

• .6 time when the fire is extinguished;

• .7 time when the fire is re-ignited, if any;

• .8 time when the oil flow for the spray fire is shut off;

• .9 time when the fire-extinguishing system is shut off; and

• .10 time when the test is finished.

 The following should be recorded:

• .1 damage to any system components; and

• .2 level of fuel in the tray(s) to ensure that no limitation of fuel occurred during the test.