(Photograph courtesy of John Burt Associates Limited)
The controls, switches etc. for foam systems should be arranged in such a way that the foam supply starts automatically or can be initiated at the activation point for the monitors.
With remote operation capability, the systems can be set up prior to use so as to avoid the necessity to operate each of the monitor valves independently before the system can be used.
Remote activation is operationally advantageous where the number of helideck crew members are limited. Also, if the monitors are correctly set to douse the fire area, helideck crewmembers are potentially less exposed to the fire hazard.
11.5.7 Water / Foam Systems
The provision of a water / foam hosereel system, in addition to the monitors, provides greater operational flexibility when dealing with an aircraft fire or aviation fuel spillage.
Compact, self-contained, skid mounted units can be obtained which provide the designer with flexibility for locating the unit on the perimeter of larger helidecks, outwith the zones that have a height restriction.
(Photograph courtesy of John Burt Associates Limited)
These units are supplementary to the main system, and their output is significantly less than a monitor. The foam making capability (supply time) will be entirely dependent on the size of the storage tank and the foam fill.
Normally, these units come fully equipped with a jet / fog nozzle and branchpipe and approximately 30 metres of 1.’ hose.
It is essential to ensure there is sufficient hose length available to reach around the helideck easily. On very large helidecks hose length may need to be increased.
11.5.8 Hydrant Systems and Equipment
Hydrant systems, hoses, in-line foam inductors, foam branch pipes and nozzles are normally provided as supplements to the foam / water monitor system.
NOTE: On helideck inspections it is sometimes found that there are insufficient hand hose lines to reach all parts of the helideck. For ease of use the hand lines should be approximately 1.’’ diameter.
Hydrants and Hoses
Hydrants with flaked hose lines are often specified as supplementary equipment to the fire monitors. Serious thought should be given to the practical use and application of this type of equipment if it is being considered for ‘new build’ or modified helidecks. On older installations and vessels 2.’ diameter units were often specified.
Nowadays, the designer should consider the operational benefits of using a 1.’ system. It should be noted that under normal operating conditions it takes two people to control a 2.’ hose which would give the greater discharge for directing the nozzle stream at a fire.
The positioning and selection (e.g. straight or 45° angled couplings) of hydrant outlet types on helidecks (that are normally located on the monitor platforms) must take into account the available space and the lay and curvature of fire hoses when they are under pressure in a confined space.
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