The LWF Blog
Fire Engineering Design and Risk Assessment – Provision of Firefighting Shafts – Part 50January 31, 2020 12:55 pm
In LWF’s Fire Engineering blog series for Architects and others in the building design business, we have been discussing firefighting and what provisions must be made for firefighting activities in a building. In part 49, we examined some of the criteria given in different guidance documents and in particular, how it is recommended that a firefighting lobby should be used as access to the accommodation from a firefighting lift or stair as a single fire door is not adequate, when for firefighting purposes, the fire door will be propped open by a hose line anyway and so the protection is immediately lost. In part 50, LWF discusses some of the challenges facing firefighters in high-rise firefighting and fighting fires at basement levels.
In 2008, an amended version of ‘Generic Risk Assessment 3.2 High-rise Firefighting’ (PDF) was published which stated the following:
“Prior to utilising a firefighting lift the shaft should be checked to ensure that it is clear of smoke. If clear, the crews can take the lift, ensuring its operability by stopping at intermediate points to confirm control of the lift and to check the shaft again for smoke.
Should smoke and the products of combustion enter areas outside the fire compartment including staircases consideration should be given to establishing the provision of inlet air at ground level to improve staircase ventilation. Subject to appropriate control measures the use of positive pressure ventilation can assist this process.”
Some jurisdictions require even more stringent operating procedures, recommending that firefighters should stop the lift every 10 floors to check that the lift remains operable and controllable, as well as ensuring the shaft is clear of smoke and that the firefighters should exit the lift five floors below the floor of fire origin.
Firefighters approaching a basement fire would not be able to use the same guidelines as if they were approaching a fire on an upper floor. Because the firefighters will be travelling down from a point above the fire floor, access to accommodation in a basement should be through a firefighting lobby. It would never be appropriate to use a firefighting lift to access a basement level fire, as there would only be single fire door protection between the lift lobbies and the accommodation. Additionally, there would be no way of assessing initial signs of fire penetration into the shaft.
In simple physical terms too, it’s far easier for firefighters to carry their equipment down steps to a basement level than to carry it to a height of 18 m.
It is not, therefore, necessary or safe to install a firefighting lift which accesses a basement level in ordinary circumstances. If some particular circumstances meant that such a lift was a requirement, special safeguards would have to be put into place to make it safe to use.
In part 51 of this series, LWF will look at recommendations for firefighting based on time limitation. 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.