Pumping Concrete through an Operational Underground Station

In order to be able to construct new pedestrian tunnels between existing platforms at Kennington Station, ready-mix concrete needed to be supplied below ground into the tunnel construction area.

The option of delivering ready-mix concrete via engineering trains at night was investigated but ultimately discounted due to various impracticalities. Therefore the only remaining option was to deliver from ready-mix wagons at surface level and pump through the station down to platform level.

Normally such an operation would have to be carried out at night when the station was not in use, however this would have caused disturbance to the neighbours that were in very close proximity.

London Underground therefore had to be persuaded that concrete could be pumped through the station via pipework installed through the station and staircase, without presenting an unacceptable safety hazard to pedestrians.

The successful solution involved rigid pipework that was installed along the edge of the staircase and walkways and that was boxed in using timber. This allowed the concrete deliveries to take place during the daytime whilst the station was operational and minimising disturbance to the neighbouring residents.