4 Lines Modernisation


The Project requirements were for the total renewal and upgrade of signal and service control systems on the 4 Lines Modernisation (4LM) network. Primary purpose being for upgraded railway to operate with a peak service of 32 trains per hour (TPH) in the central areas. Kelly Rail installed the radio based SelTrac system and are offering to TFL, full Design, Supply, Installation, Integration & Validation of the SelTrac system along with managing the migration of the ATC system whilst adopting a planning and implementation approach.
The 4LM Programme is for London Underground Ltd (LUL), consisting of the modernisation of Sub Surface Rail (SSR), Automatic Train Control (ATC), Signal and Control Systems on the Metropolitan, Hammersmith & City, District and Circle lines to increase capacity and reduce journey times along the lines.

Scope of Work

  • Detailed intrusive Surveys including CAT scanning
  • Wayside equipment Survey and mark up for design
  • SelTrac and Legacy signalling equipment Installation Trackside
  • Installation of SelTrac and Legacy signalling equipment in Signal Equipment Rooms, Electrical Switch Rooms and Interlocking Machine Rooms
  • Equipment delivery by Trains into ESRs and SERs
  • Complex lifting of equipment into SERs and ESRs
  • SelTrac and Legacy signalling equipment  Installation of Depots to Sidings
  • Interfaces and Coordination with Others
  • Deliverable Documents

Key success factors and innovations

Thales and Kelly Rail have achieved several milestones by working collaboratively. Kelly Rail has successfully enabled 32 trains per hour (TPH) through the central areas of the Metropolitan, Hammersmith & City, District and Circle Lines, providing a step change in passenger capacity and a reduction in passenger waiting times.







of cable installed

1000 +

bases installed