New DLR fleet in build

ARRAN RUSLING, Transport for London’s Programme Delivery Manager for the DLR Rolling Stock Replacement Programme, updates PHILIP SHERRATT on progress with the new CAF fleet

New train mock-up: this 15-metre vehicle was delivered by CAF to TfL last year and was based at the Tunnelling and Underground Construction Academy (TUCA).
Courtesy TfL

Construction is getting underway on a new fleet of trains for the Docklands Light Railway Transport for London has ordered 43 trains from Spanish manufacturer CAF, replacing all but the newest trains currently operating on the DLR.

Each five-car train will be around 86 metres in length, equivalent to three of the current fleet coupled together. The older B90, B92 and B2K fleets will be replaced (totalling 94 shorter trains), with a further 10 new trains ordered to meet projected demand growth, including ensuring all services are operated at maximum length (some currently run as two-car formations). The more modern B07 units will be retained to work alongside the new CAF fleet.


TfL signed the contract for the new fleet with CAF in June 2019. The preliminary design review on the new fleet was completed on 1 May last year, with detailed design completed in November – this was on target despite the difficulties presented by Covid. While the initial intention had been to undertake design workshops at CAF’s facilities in Spain, TfL’s Programme Delivery Manager Arran Rusling explains remote reviews were implemented instead.

Before Covid, trade union representatives and operators travelled to Spain for a series of design workshops. ‘We wanted to close out and deal with human factors and operability issues and ensure the design was optimised for the end user’ Mr Rusling explains.

In September a scale mock-up of the new stock was delivered to the UK. This single composite carriage incorporated features found throughout a full train and enabled stakeholders to visit and confirm that suggested adaptations had been incorporated. The 15-metre carriage was based at the Tunnelling and Underground Construction Academy (TUCA) in Ilford, and following the end of the design phase was moved by road to the London Rail Academy at the College of Haringey, Enfield and North East London (CONEL), where it is being used to provide practical training for students and apprentices.

Elements of the design which evolved following contract award have included changes to the front-end trim and headlight arrangements, as well as refinement of the livery to bring it more in keeping with the design principles of other TfL fleets such as the London Overground and Elizabeth Line trains. A particular focus has been on usability for the Passenger Service Agents (PSAs) – these members of staff usually circulate through trains to check tickets and assist passengers but are occasionally required to operate trains manually from the front. Early feedback regarding sightlines when they do this led to the glass in the side windows at the front being extended to improve visibility of stop markers, while a further change is provision of heated glass in side windows to avoid these steaming up in wet conditions.

First bodyshells: CAF will build four pre-series trains which will initially be tested in Spain before they are delivered to the UK.
Courtesy CAF

Within the passenger saloons, the positioning of the train door key used by the PSAs has been adjusted so it is at a lower, more comfortable height for all users. For passengers, grab pole arrangements have been optimised to provide more efficient hand holds, and an updated moquette design has been selected. Each train will have three wheelchair areas and three multi-use areas for bicycles and luggage, and ensuring a clear delineation between these has been a priority.


Manufacture of the new trains began in December 2020 at CAF’s Beasain factory in Spain. This has included material assemblies and assembly of the first roof structures and bodyshells. An initial four pre-series trains will be built before CAF mobilises the main production build.

TfL has now started First Article Inspections (FAIs) of 45 key sub-system components, the first of which took place on 7 January. As with design reviews, these are being carried out virtually; normally they would involve TfL’s own staff visiting sub-suppliers in various locations. Instead, an in-country resource has been procured and a series of high-definition video feeds used to carry out the FAIs so TfL staff can witness the inspections and provide quality assurance. ‘It’s been a fantastic collaborative effort from CAF and TfL to get to where we are given the challenges of Covid’ says Mr Rusling. While he praises the ingenuity of this process going virtual, Mr Rusling says in-person inspections are still preferable, although on the DLR project the limitations on foreign travel mean the plan is for all FAIs to be completed virtually, the last ones taking place during May.

Once the first train is completed, it will be required to carry out 20,000km of fault-free running on the test track at CAF’s Beasain facility. It will then transfer to the UK to begin around nine months of testing on the DLR network. This will comprise two elements – integration testing with the Thales automatic signalling system and platform-train interface testing to prove the train in operating conditions. Initially these tests will take place at night, before daytime testing begins during off-peak hours between service trains.

Richard Garner, CAF’s UK Director, comments: ‘CAF is proud that our trains will support the Mayor of London’s Transport Strategy to make the capital a greener, more accessible place to live, work and visit as well as supporting new jobs and homes.

‘Our state-of-the-art Metro vehicle design is ideally placed to meet the specific demands of the UK’s busiest light railway and the requirement to increase frequency and passenger capacity on the DLR.

Taking shape: bodyshell of a driving vehicle under construction at CAF’s Beasain factory.
Courtesy CAF

‘In addition, CAF’s trains will deliver the very latest in passenger comfort, convenience and safety – equipped with the latest audio and visual real-time travel information, air conditioning, mobile device charging points, dedicated wheelchair spaces and multi-use areas accommodating pushchairs, bicycles and luggage.’


The DLR was built with a GEC-Alsthom inductive loop fixed block signalling system and was subsequently retrofitted with a Thales Seltrac system.

During 2018 the Vehicle On-Board Controllers (VOBCs) were upgraded with new faster processors. This is the same processor used for the Thales signalling system on the London Underground Jubilee and Northern Line fleets and as part of the Four Lines Modernisation (4LM) programme for the sub-surface lines.

Coupled with the arrival of the new trains will be the introduction of the Thales On-Board Platform (TOP) signalling system, with the chief advance being an upgrade to the VOBC, fitted with a much more powerful processor; these will operate alongside the upgraded VOBCs fitted in the B07 fleet. New features will include an automatic train operation (ATO) manual mode and a more modern controller. The Thales system is similar to that used by CAF’s Santiago Metro fleet, although that system is radio-based, whereas the DLR’s is loop-based.


■ Five-car formation: DM1-T1-M-T2-DM2 (end and middle vehicles motorised)

■ Total capacity 792 (157 seated) – all longitudinal, except transverse front rows

■ Air-conditioned

■ USB sockets

■ Walk-through carriages

■ Lights above doors providing visual indicator of open/close status

■ Three wheelchair areas and three multi-use areas

■ Electronic customer information system (CIS), able to display customised information and travel updates in real-time

High-tech features: image from the mock-up carriage showing electronic information display and lights above the doors indicating whether they are open or closed.
Courtesy TfL
More sidings coming: an overall view of the northern stabling sidings at Beckton DLR depot on 31 October 2019, with B92 stock train No 86 nearest the camera. In a revision to the plan to expand the depot, prompted by the impact of Covid, additional sidings on the north side will be built first, with the southern sidings deferred to later in the programme.
Antony Guppy

TfL negotiated the VOBC upgrade with Thales in advance of the rolling stock tender, and this element has now been sub-contracted to CAF to manage, with detailed design integration underway. A separate contract with Thales signed in October 2019 covers the signalling upgrade, with preliminary and detailed design completed and software development underway.


The growth in size of the DLR fleet means more depot space is required. This challenge is being met by expansion of the main depot at Beckton.

Plans to create additional capacity at the depot have been impacted by Covid. Originally the plan was to build three new sidings on the south side of the depot, which would provide additional stabling space while work takes place on the north sidings. A new maintenance building also features within the plans for the site.

However, the pandemic took hold just before TfL was looking to place the contract for the south sidings work last April, and this has forced a rethink. ‘To protect the critical path, we’re deferring the south sidings work to the back end of the programme and starting on the north sidings first instead’ Mr Rusling explains. ‘This means we will need to find additional stabling space for four trains elsewhere on the network for eight months while this work takes place.’

A contract for the north sidings work has been awarded to Buckingham Group, and work on site began in February. The scope of works entails building new stabling roads with additional track, new switch and crossing (S&C) units, platforms, walkways, lighting, communications and signalling.

A separate single contract will be let for the construction of a new maintenance building and the south sidings work, as Mr Rusling says having two different contractors on site at the same time could create additional risk.

Also planned at Beckton is the extension of the depot’s test track across the top of the site; this track will be used for testing the new trains and their interaction with the Thales signalling before they begin network testing. The current track will be taken out of use at the end of May, coming back into use in early 2022. Initially it will be the same length as now, but when the new maintenance shed is built it will be extended to 750 metres in length. An increase in permissible speed on the test track to 50km/h will assist with the testing of the new trains.


While the design of the new trains was completed on schedule, Covid has impacted the manufacture of the fleet due to the closure of CAF’s factory in Spain and the impact on sub-suppliers of components. ‘CAF has done really well to get its factory back up and running, with mitigations such as moving from a two-shift to three-shift pattern to spread its workforce’ Mr Rusling reports.

This impact means the planned date for the first trains entering service has slipped from late 2023 to early 2024. The tenth train is due to be accepted in mid-2024 with the full fleet of 43 trains in service by early 2026.

The current plan is for the 10 additional trains for growth to be introduced first before replacement of the old fleets starts. However, Mr Rusling says there is flexibility to amend this plan depending on how passenger demand recovers post-pandemic. ‘Our current thinking is we need the additional capacity on the Woolwich route first’ says Mr Rusling, noting that this extra capacity comes both through the increased carrying capability of the new trains (around 20% up on the present trains) and the boost of having a larger fleet.

‘We’ll continue to validate our plan as we get more data on how the demand build-up happens, and this will influence our training plans for PSAs’ Mr Rusling adds.


While the initial order is for 43 trains, TfL has options in its contract with CAF for an additional 34 trains.

In October 2018 TfL was awarded Government funding through the Housing Infrastructure Fund (HIF) towards improvements on the DLR intended to unlock new housing. An agreement worth £281 million was signed between TfL, the Greater London Authority (GLA) and the Ministry of Housing, Communities and Local Government (MHCLG) in December 2020, covering the purchase of an additional 14 trains from CAF, further expansion of Beckton depot and a contribution to works at Poplar which would see a deck built above the depot and station to support additional housing. A £10 million contribution to a new station at Thameside Wharf, part of the original HIF bid, has now been removed from the scope.

Provision for PSA operation: although usually based in the passenger saloons, on occasion Passenger Service Agents operate DLR trains from the front, and the new stock will include a small barrier to ensure they are not disturbed when doing so.
Courtesy TfL
Walk-through carriages: in this view of the mock-up note the USB sockets on the equipment cabinet – these are also found next to the inter-vehicle gangways.
Courtesy TfL

Preliminary works and feasibility studies are underway concerning the Beckton element, which would see the depot extended to the south on land currently owned by National Grid. MHCLG and TfL/GLA have entered into the agreement on the condition that confirmation must be provided of TfL’s ‘financial certainty’ – linked to Government funding negotiations with TfL – prior to any significant expenditure on the programme.

The HIF bid funding will deliver improvements to the frequency and capacity of the Lewisham and Woolwich branches of the DLR, beyond the enhancements planned in the base order for the new trains, with the additional 14 trains entering service during 2026. The priced option in the contract with CAF for additional trains runs until the end of 2023 without a break in production, or until the end of 2025 with a break in production.

Although TfL’s investment programme is contingent on Government funding, further feasibility work was announced in December towards an extension of the DLR from Gallions Reach to Thamesmead, improving connectivity across the river; if this proceeds, it too could mean additional trains are needed.