fire main (standpipe) water

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When engineering the firefighting mains and providing adequate water storage in a high-rise building, how much water is adequate? This article proposes, and offers reason for, some design changes relevant to any review and update of BS 9990:2015 to include:

1. Double landing valve/outlets at every floor level.2. 150 mm dry rising mains, increasing available pressure and flowrates, to levels more closely comparable with those available from wet rising mains.3. Wet rising mains to be installed in buildings >18m, where hydrants within 200 metres of the building are unable to meet adequate water provisions >1500-2250 l/min at the highest outlets.4. Wet riser flows increased to 2250 l/min (3 x 750 l/min) and should be provided where there are:• Open-plan compartments exceeding 250 m2 in floor area, in any building greater than 50 metres in height to the highest occupied floor, with a mean fire load > 300 MJ/m2; or where > 250 m2compartments having a maximum of 30% exposed mass timber to one surface of wall or ceiling, in any building greater than 30 metres in height, to the highest occupied floor. (See Table 5)5. The definition of ‘adequate water’ is described, in accordance with BS PD 7974-5, and measured by l/min against (1) floor area fire involvement (GCU) (m2), (2) Heat Release Rate (kW/m2), (3) Fire Load (MJ/m2).

Successful and safe firefighting requires immediate access to adequate supplies of water. The access to, and proximity of, those water supplies directly affects the resources and tactics firefighters are able to deploy at an incident. The design, configuration, and use of rising fire mains in the UK were originally based on a vast amount of live fire research involving much international collaboration, undertaken between 1953 and 1970 by the Fire Research Station under the auspices of the Department of Scientific and Industrial Research (Fire Offices Committee). Operating as the Joint Fire Research Organisation (JFRO), this body of researchersformed the foundation for national firefighting intervention capability, fire protection facilities and fire appliance design standards.

The  authors of BS PD7974-5 (fire service intervention water provisions) brings  you the source data and methodology provided in the published document.