Challenge
A major upgrading of King’s Cross underground station was required to meet increased demand. The existing Grade 1 listed station was being returned to its former glory, including the original 1951 façade, ticket hall and main train-shed roof. The project includes expansion and redevelopment of the existing ticket hall and the construction of two new ticket halls underground, involving major interfaces between London Underground and Network Rail. Powershield’s element was to supply fire doors. Fire safety in public buildings is always a top priority, even more so in underground stations.
This project required steel fire doors within the tunnel interfaces between underground access points, stations and ticket offices. The fire doors needed to be held open on magnets to maximise foot flow in these busy tunnels and only close to provide compartmentation in the event of a fire. Other design requirements for the doors included; the need to be pivoted and flush within the wall assembly in the open position, match the stainless steel shot peened tunnel finishes, have flush vision panels, and provide the 60 minutes fire resistance and smoke control without any latches or locks fitted to the door.
Solution
Powershield faced a very tight programme and before manufacture could commence the doors had to be designed and a prototype built. Doors were then fire tested through Exova Warringtonfire to BS EN 1634-1 2008 to prove the door’s integrity. Despite the onerous conditions of the test, it proved successful; achieving well in excess of the required 60 minutes resistance. Following the success of the test, full manufacture began and the doors were delivered to site. Doors were installed in challenging conditions, being underground and with tight access and restricted working hours however all 42 doors were installed to programme and are now in location providing an important element of the fire safety within the station complex.