Case Study Control and Display

Piccadilly Circus - Fire Main Repair

Piccadilly Circus station on the London Underground (LU) is located directly beneath Piccadilly Circus, one of London’s most popular tourist destinations, featuring the famous Eros fountain which draws visitors from around the world. It is served by the Piccadilly and Bakerloo lines and is one of the few London Underground stations which have no associated buildings above ground.

London Underground (LU) is the metro system which serves London and surrounding counties. It provides a non-mainline mass transit train and station service seven days a week and is an integral part of the transport system in London.

L.B. Foster Technology Services was contacted by London Underground to identify a solution following a burst in an original Victorian cast iron fire main located between the station and pipe subway, within the tunnel ring wall directly underneath the Eros fountain at street level.

Requirement

Piccadilly Circus station’s upper machine chambers, spiral staircase and cable run had all flooded. Thames Water had attended the site and managed to slow the leak by isolating an isolation valve located on Piccadilly Road.

London Underground tasked L.B. Foster Technology Services with getting the mechanical fire systems back online at the station, using minimal disruption and excavation to the internal/external station, structural tunnel ring, pavement, road and Eros fountain.

Our Solution

Once the Thames Water isolation valve was closed, Piccadilly Circus station was left with no water supply for critical fire protection and prevention services, including automatic wet sprinklers, wet hydrants, multiple escalator wet sprinkler systems, as well as the domestic water supply.

The Victorian cast iron pipe was cut either side of the rupture/break; one cut within the pipe subway and the other in the station cable run. The original cast iron pipe within the wall, buried under the Eros fountain, remained in situ, acting as a protective sleeve. The new stainless-steel pipe was then fed through the cast iron pipe sleeve, connecting to the station’s fire main within the cable run and to the Thames Water main within the pipe subway. Carrying out the repair in this way meant no excavation works were needed.

The pipe subway was classed as a ‘confined space’, meaning access was limited to set times and only specialist trained operatives could enter the area, with no hot works or excavation undertaken.

The Repair on the fire main was carried out using crimped stainless steel and heavy galvanised steel fittings and pipework. The pipes were connected to the existing cast iron main using specialist connectors.

“The response from the team at L.B. Foster was exceptional. Once on site they quickly identified a workaround solution that meant there was no requirement for excavations, which meant the repairs could be made quickly and efficiently and with minimum disruption.”

Project Manager, London Underground