AECOM Wins TfL Bakerloo Depot Upgrade Feasibility Contract

LONDON, UK – Transport for London (TfL) has appointed AECOM as lead consultant for early-stage feasibility and planning on the Bakerloo Line Upgrade’s depot and sidings programme, with Arcadis in a supporting role. The contract covers Stonebridge Park Depot, the Queen’s Park area and London Road sidings at Elephant & Castle. The broader upgrade is scheduled to complete in December 2034, with new trains entering service by 2035 and replacing a fleet that has been in service since 1972.

What Does This Contract Cover?

The contract covers multidisciplinary feasibility, planning and coordinated baseline design for fixed infrastructure that must be reconfigured before a new Bakerloo fleet can operate. AECOM will integrate planning, systems engineering, rail disciplines, environmental services, digital delivery and BIM across all three sites, producing a baseline design for reconstruction of the Stonebridge Park train depot and upgraded sidings at Queen’s Park and Elephant & Castle.

No contract value was disclosed by TfL, nor was an official completion date published for the feasibility phase. The appointment builds on prior AECOM work for TfL, including design services for four proposed Bakerloo Line Extension stations and lead designer status on the Elephant & Castle Station Capacity Upgrade awarded in 2024.

Key Contract Data

How Does This Compare to Similar Contracts?

This is not the first depot-led modernisation that AECOM and Arcadis have delivered together on the TfL network. The pair previously served as construction advisers and engineering partners on the DLR Beckton Depot Upgrade, which supports the Docklands Light Railway Rolling Stock Replacement programme (Source: AECOM / TfL, 2025).

Comparable enabling infrastructure work is also underway on the Piccadilly Line Upgrade, where Siemens Mobility is supplying 94 new trains alongside depot upgrades at Cockfosters and Northfields (Source: Siemens Mobility, 2022). The Bakerloo approach — contracting depot and sidings design before the rolling stock order is placed — reduces integration risk on a line whose current 1972-stock trains are already beyond the normal replacement age for London Underground assets.

The contract also sits within a wider European market shift: roughly 90% of Europe’s control, command and signalling market is now tied to modernisation of existing networks rather than new-build lines (Source: RailMarket, 2025). No comparable depot-only feasibility contract on the London Underground has had its fee disclosed publicly in recent years, leaving a gap in direct cost benchmarking.

Editor’s Analysis

By commissioning depot and sidings design ahead of fleet procurement, TfL is de-risking the interface between new trains and legacy infrastructure — infrastructure that remains critical to any future Bakerloo Line Extension into south-east London. The sequencing deliberately mirrors the DLR Beckton Depot model, where AECOM and Arcadis have already proven the advisory chain. If the feasibility phase produces a baseline design acceptable to TfL, both firms are strongly positioned to convert this award into delivery-stage revenue later in the programme, particularly as the 2034 completion target leaves limited schedule slack.

FAQ

Q: When will the Bakerloo Line get its replacement trains?
A: TfL’s current programme targets completion of the upgrade by December 2034, with new trains entering service by 2035. The 1972-stock fleet being replaced is more than 50 years old.

Q: What work does the AECOM depot and sidings contract actually cover?
A: AECOM will lead feasibility, planning and baseline design for Stonebridge Park Depot, the Queen’s Park area and London Road sidings at Elephant & Castle. The infrastructure must be rebuilt or upgraded before new rolling stock can be stabled, cleaned and maintained.

Q: Does this contract include the Bakerloo Line Extension to Lewisham?
A: No — the depot and sidings feasibility study is part of the core Bakerloo Line Upgrade, not the Bakerloo Line Extension. AECOM was separately selected to provide design services for four proposed new extension stations.