The LWF Blog

Fire Engineering Design and Risk Assessment – Provision of Firefighting Shafts – Part 51

January 31, 2020 12:58 pm

In LWF’s Fire Engineering blog series for architects and others in the building design business, we have been discussing firefighting. In part 50, we considered the potential situation with a fire in a basement and how the firefighters would be expected to access the area. In part 51, we continue looking at access for firefighters.

When considering how far into a compartment the firefighters will be able to go and what distance they can affect with a jet of water, it is reasonable to assume a fixed figure of 50 m, which is based upon two lengths of hose, plus the jet throw of a further 10 m. This figure can be measured from the fire-resisting doors which separate the fire compartment from the firefighting shaft. From this calculation, it is possible to calculate how many firefighting shafts will be required.

However, it is time which is of the essence in any firefighting endeavour. The attendance of the Fire Service to the scene with pumps is measured in time and not distance. The speed at which the firefighting lift reaches the floor of fire origin is also measured in time. It would seem logical that the total travel limitation for a fire attack should be based upon the time and equipment, rather than on distance.
CIBSE’s Guide E therefore recommends the following:

– For any building with a floor up to 18 m above fire service access level, one or more firefighting shafts should be provided which should consist of a protected staircase without a firefighting lobby. This would mean that it was to the same standard as for a protected escape route. In cases where the highest floor is above 14 m, a dry rising main should also be installed.

– For any building with a floor over 18 m above fire service access level, one or more firefighting shafts should be provided which consist of a protected staircase and a firefighting lift with access to the accommodation through a firefighting lobby.

– For any building with a basement, one or more firefighting shafts should be provided which consist of a protected staircase with access to the accommodation through a firefighting lobby.

In part 52 of this series, LWF will look at the access level of the firefighting shafts. In the meantime, if you have any questions about this blog, or wish to discuss your own project with one of our fire engineers, please contact us.

Lawrence Webster Forrest has been working with their clients for over 25 years to produce innovative and exciting building projects. If you would like further information on how LWF and fire strategies could assist you, please contact Peter Gyere on 0800 410 1130.

While care has been taken to ensure that information contained in LWF’s publications is true and correct at the time of publication, changes in circumstances after the time of publication may impact on the accuracy of this information.