The TPI Re-signalling project was principally developed to ensure that LUL’s new ‘S’ type trains would be able to run on current LUL infrastructure by immunizing track circuits that operated at less than 100HZ.

In order for this to happen the TPI project had to immunise parts of the LUL District Line using single rail TI21 EBI track 200 circuits around the Upney, Upminster, Ealing Broadway, Richmond and Gunnersbury Areas.

The Upminster works comprised of the replacement of the existing AC track circuits with a combination of EBI 200 single rail jointed and double rail jointless track circuits. Single rail configurations was utilised in critical areas such as points/crossovers and critical IBJs, whilst the double rail set up was used on plain line areas.

Utlising very tight possession arrangements over 206 new TI21 EBI tracks were installed, in conjunction with modifications in existing location cases, DISS box installation and many other trackside installation works. Aside form the main scope new 650V power cable was installed, jointed and commissioned. All works were commissioned in 4 stage strategy at Elm Park, Hornchurch, Dagenham East/Dagenham Heathway, Upminster Bridge/Becontree and Upminster Depot.

RTIS supported Atkins on this project with skilled signalling teams for a period in excess of 13,500 man hours with zero reported accidents or RIDDORS. They were particularly commended for their strong technical ability whilst also being highly praised for their efforts and contribution throughout the 9 month project, both in a supervisory and installation capacity.


  • Installation of Track Circuit Interrupters
  • Installation of TI21 EBI track circuits
  • Signalling Bonding works including check rail, CRR, S&C and IRJ
  • Installation of U-Bonds for temporary dual use of EBI/AC track circuits
  • Installation of new disconnection boxes for track circuits
  • Installation & Termination of Multi Core Cables & Power Cables
  • Cable Jointing of various multi core signalling and power cables
  • Quality and Audit checks on 4ft equipment and works in location cases
  • Installation Support for 4 stage Signalling Commissionings


Atkins Rail









Project value












April 2014 — Feb 2014