Transport for London reveals reason for delays to new DLR rolling stock B23, expected to enter service later in 2025

After a long hiatus, the new £942 million Docklands Light Railway rolling stock B23 is finally back in trial service. Transport for London (TfL) has explained the reasons for the delay in response to a Freedom of Information request.

Your exclusive sneak peek of the new DLR trains 👀

Coming soon. Find out more about the new features ⬇️ https://t.co/eYvOKFOfjy pic.twitter.com/DLHxD2aTgt

— TfL (@TfL) September 1, 2025

Request ID: FOI-1452-2526
Date published: 08 September 2025

Please find attached a document detailing the initial programme of the manufacture of the new DLR trains. Please note that this document was prepared in 2019 (prior to the pandemic) by Construcciones y Auxiliar de Ferrocarriles, S.A (CAF) and the timescales included reflect the agreed timings for the programme with the supplier at the time the programme was accepted. Also note, the dates in the supplier programme differ to those in the client-side programme.

The introduction of the new fleet of DLR trains was delayed when a pre-existing issue was identified within the signalling system, which impacted the necessary testing and compounded earlier delays caused by issues during train testing. COVID-19 also impacted the timings, and the new trains were delayed in coming to the UK because of the contractor building the required depot going into administration. We expect the first new train to passenger enter service later this year.

The document in question is a project programme for the Docklands Light Railway (DLR) Rolling Stock Replacement Project, dated 21 November 2019. It sets out the plans to procure and introduce 43 new trains to the DLR network.

It highlights key milestones, outlines the tasks still to be completed, and provides a timeline for delivery. The report also names the departments and individuals responsible for different areas of the project, such as contract negotiations and engineering. With its detailed use of codes, dates and personnel references, the document appears to be an internal report designed to support project oversight and coordination.

The document can be accessed on the TfL website by clicking the request ID number above.

Now TfL, let’s get the ball rolling and introduce more B23 rolling stock trains to the DLR. 😀

Just to clarify briefly, I did not make the Freedom of Information request, as TfL stated that they publish the response online without disclosing any personal information of the requester. A similar procedure applies with the ‘What Do They Know’ website, where anyone can submit a FOI request to a UK governing body, and the correspondence is available for the general public to view.

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