Jubilee Line trains
Nine-year overhaul project

Overview and Objectives

TP Matrix is supporting Alstom with its nine-year overhaul of the 63 trains that serve the Jubilee Line. Our involvement in the overhaul is set to run until September 2024.

The main objectives are to significantly improve and extend the reliability of the fleet until 2036, possibly longer, thereby reducing ongoing maintenance costs and improving operational performance.

TP Matrix’s approach - overcoming obsolescence and providing rigorous testing

​As expected, with the Jubilee Line fleet being in service since 1997, a number of electronic component obsolescence issues were identified while developing the scope of work for the overhaul.

TP Matrix worked closely with Alstom’s engineering team and presented like-for-like alternatives which were then trialled and subsequently approved through Alstom’s design query process.

The products being overhauled by TP Matrix for each train set include:

  • Auxiliary converter electronics
  • Wheel slide and speed control units
  • Power supply units
  • Gate drive panels 
  • Thyristor firing panels.


Rail Project - Virgin Trains
Rail Project - Virgin Trains

Weekly, TP Matrix will receive 70 individual PCBs with 1,065 components being replaced.

With such a short turnaround time on each train set, TP Matrix’s lead engineers, using existing test and inspection documentation, have developed Automated Testing Equipment (ATE) to provide a full functional test prior to the units being returned to the depot. This ATE has significantly reduced the testing time required.

In preparing for the project, TP Matrix has invested to expand and upskill its engineering team and apprentices. All production staff involved in the project are trained to IPC-7711 and IPC-A-610 standards.