The LWF Blog

Fire Engineering Design and Risk Assessment – Ultra High-Rise Buildings – Part 57

September 2, 2019 12:17 pm

In LWF’s Fire Engineering blog series for Architects and others involved in building design, we have been looking at how buildings are designed with firefighting in mind. In part 56, we discussed the use of refuge floors in ultra high-rise buildings. In part 57, we continue talking about ultra high-rise buildings and the provision of access for firefighting purposes.

The usual firefighting process involves firefighters preparing and carrying the equipment necessary into the building in question and up any stairways until they reach the floor below the floor of fire origin. However, this approach would be obviously impossible for practical purposes in an ultra high-rise building. A fire on the upper floor of an ultra high-rise means that firefighters must be able to access a lift to transport them and their equipment to a point below the fire floor.

In 1992, Paul Grimwood wrote a book called ‘Fog Attack’ Firefighting Strategy & Tactics – An International View which discussed the practicalities of firefighters in the United States walking up steps in high-rise buildings rather than using lifts. He referred to a study which had taken place in Ohio which suggested that from the firefighters setting out from their station which was two miles away from the fire site, to the point where they began to attack the fire on site could be calculated at around one minute per floor, e.g. 12 minutes to reach a fire on the 12th floor of a building with all equipment primed and ready.

Various papers have been published on the basis of actual or simulated events in order to evaluate fire service access to buildings. These studies have culminated in recommendations such as provision of a means of assessing required locations of landing valves, recommendations for the provision and design of firefighting shafts and examples of access for firefighting, and have relevance, whether a building is considered high-rise or ultra high-rise.

The provision of refuge floors in ultra high-rise buildings in effect cuts the building into several high-rise buildings (or vertical sectors) of between 8 and 25 floors. If refuge zone floors and vertical sectors were established in practice, firefighting access could be based on:

– High speed lifts which transport firefighters and their equipment to the refuge floor below the fire floor.
– Additional lifts which would transport firefighters and their equipment upwards from the refuge zone to all floors in that vertical sector.
– Power supplies which are duplicated and protected so that no single event could cause them to fail.
– Landing valves provided, with relevant standards for firefighting shafts and access for firefighting to be applied within each vertical sector.

In part 58 of this series, LWF will consider fire attack access and fire attack planning. 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.