Acton Train Modification Unit.

London Underground’s new train modification unit (TMU) in Acton forms part of, and is a key enabler for, their Central Line Improvement Programme (CLIP), which will see the Central Line fleet upgraded. 

A large-scale project, the £20m train modification facility provided London Underground's depot with a new 7,815sqm workshop at the existing Acton site, complete with pits, cranes and train jacks. 

BakerHicks provided RIBA Stages 3-6 design services, including civil and structural, architectural and permanent way, for the facility, which can handle up to five trains at a time, as well as for the associated accommodation block providing welfare and office facilities for 100 staff. With sustainability a key concern, the design incorporates a blue roof drainage system and other features such as photovoltaic panels, supporting the project in achieving London Underground’s desired CEEQUAL rating.

The BakerHicks team with supply chain partner PBH Rail also provided the design for the track and supporting infrastructure on the approach to the new 160-metre-long facility. This incorporated four pitted rail tracks and one bogey road, as well as new tracks and turn outs to connect with London Underground’s existing network.

Located within an existing facility, work on the new unit had to be undertaken without disrupting existing operations. This also meant great care had to be taken with the formwork foundations, given the proximity to existing buildings, to minimise the amount of excavation required and mitigate risk associated with temporary works. The project team also had to navigate through the challenges of the Covid-19 pandemic, ensuring appropriate staff welfare programmes and protocols were in place.

With the track design requiring a complex approach into the depot on a tight curve before fanning out into the five individual roads, BakerHicks conducted a digital ‘fly through’ to help them detect potential clashes and pinch points in advance.