Installing CBTC in the Underground means installing radio antennas in the tunnels – approximately 450 of them – all linked by cables back to the control centre.
The method originally envisaged for the fixing of the signalling equipment in the tunnel areas was to use mobile scaffold towers. These would obviously have to be continually erected and dismantled, configured for access to the required parts of the tunnel profile at every one of the 450 antennae locations, and all within the very short possession timeframes available.
As this approach introduced some challenges, London Underground and Thales turned to specialist plant supplier Total Rail Solutions (TRS) which proposed to use mobile elevated work platforms (MEWPs). With their ability to easily reach any required part of the tunnel profile, the advantages were immediately apparent. That is, providing suitable MEWPs could be modified for the special constraints of the London Underground and be approved for use on its infrastructure.
Dee McGinn, senior project manager of automatic train control for TfL, emphasised that MEWPs introduce some safety benefits and improve efficiency by allowing teams to achieve more in the limited time available during possessions.