AECOM Secures London Bakerloo Line Depot Study Contract

LONDON – AECOM, with Arcadis as delivery partner, has been appointed by Transport for London (TfL) to define depot and stabling-side upgrades at three sites that will underpin a future Bakerloo Line fleet replacement. Covering Stonebridge Park Depot, the Queen’s Park area and London Road sidings near Elephant & Castle, the feasibility, planning and option-development contract is an enabling step before — not an order for — new rolling stock. The Bakerloo fleet in question entered service in 1972 and, at about 53 years old, is the oldest rolling stock in daily passenger operation in the UK.

What Does This Contract Cover?

The study will produce a coordinated baseline design for adapting maintenance and stabling facilities at all three locations, but it contains no rolling stock supply element. TfL requires this infrastructure evidence before it can progress a train-replacement business case, with the work spanning planning, systems engineering, railway disciplines, environmental services, digital delivery and Building Information Modelling integration.

The contract is a scoping exercise, not a construction award: no works at Stonebridge Park, Queen’s Park or London Road are authorised by the appointment itself. The baseline design is intended to give TfL a technical foundation for later stages of the wider Bakerloo Line Upgrade programme, which the operator links to reliability, capacity and passenger-experience improvements. (Source: TfL, 2025)

Key Contract Data

How Does This Compare to Similar Contracts?

European rail investment is increasingly directed at renewing legacy assets rather than building new ones, and TfL’s infrastructure-first approach to fleet replacement reflects that trend. Europe accounts for almost half of the global communication, control and signalling market, and smart-signalling deployments have improved Continental European operational efficiency by roughly 19%, versus 18% in the United States; this renewal-led pattern is expected to persist through 2025 and beyond. (Source: railmarket.com, 2025)

The Bakerloo study is one of several parallel European fleet-renewal efforts at very different stages of maturity. In Romania, the first 12 of Alstom’s new EMUs entered commercial service on 20 November 2024 between Bucharest North and Brașov, while Bulgaria’s new mainline fleets are still in testing or production, with deliveries concentrated and expected to be complete by August 2027. (Source: railway.supply, 2024) Neither of those programmes is supporting rolling stock that had already passed its 50th anniversary, underscoring the unusually compressed infrastructure timeline the UK now faces.

The closest same-operator comparator is AECOM’s separate role on the Docklands Light Railway Rolling Stock Replacement programme, where the consultancy is supporting the upgrade of Beckton Depot to accommodate a new DLR fleet. TfL is following the same sequencing logic on the Bakerloo Line: prove the depot solution before committing to train procurement, a structure that keeps future fleet competition open. The value of the Bakerloo feasibility appointment was not disclosed, and no completion date for the study has been published.

Editor’s Analysis

By commissioning this study now, TfL is attempting to build an infrastructure buffer that can later be converted into a full fleet-replacement programme once central government funding is secured. The engineering baseline produced by AECOM will define the physical envelope within which future train builders must work, effectively shifting the commercial centre of gravity from the train itself to the depot that must house it. Given that European market analysis points to network modernisation — not new-build expansion — as the dominant driver of rail investment, the Bakerloo Line programme is likely to remain a multi-stage, multi-decade effort rather than a single procurement event. (Source: railmarket.com, 2025)

FAQ

Q: When will the 1972-stock Bakerloo Line trains be replaced?
A: No fleet delivery date has been confirmed by TfL. New trains are dependent on funding being secured for both rolling stock and depot works, and AECOM’s study covers only the early feasibility and planning stage.

Q: What is the value of the AECOM feasibility contract?
A: The contract value has not been disclosed by either TfL or AECOM. The scope has been confirmed as producing a coordinated baseline design for Stonebridge Park Depot, the Queen’s Park area and London Road sidings.

Q: Does the AECOM appointment mean new Bakerloo Line trains have been ordered?
A: No. This appointment covers infrastructure feasibility only and does not include trains. A separate procurement would be required for any future Bakerloo Line rolling stock order.