It has been confirmed that the new fleet of CAF trains being built for London’s Docklands Light Railway will not be entering service in 2024. The confirmation came in a Freedom of Information request which requested more information on the challenges which had been experienced since the vehicles started testing on the network.
The new trains had been expected to be introduced into service earlier this year but, as with many other new items of rolling stock across the UK, this has been delayed. It now won’t be until next year that the first trains can run in passenger service. It had previously been said that there had been a number of complex challenges during testing although TfL had not forthcoming what they were.
But the FOI response does now give more detail: “We identified issues relating to the integration between the train and signalling systems and how these behave in conditions of poor railhead adhesion. The engineers have developed a plan to overcome these issues. However, while doing this, they have identified a preexisting technical issue within the legacy signalling system which has resulted in speed restrictions being introduced in some sections across the DLR network.
“Work is underway to optimise these speed restrictions, which will hopefully minimise the impact to customers on the DLR network. As a result of the legacy signalling issue, further detailed analysis is also required for the new trains, alongside existing software modifications. This has meant the new DLR trains will not be able to be introduced this year. We do now have a solution for the new trains to enter passenger service, but the initial programme is currently being stress-tested and optimised.”
Further information on the eventual introduction of the trains is expected during 2025.
Yet again CAF living up to their reputation and nickname “Cheap And ……..”
The list of operators to buy stock from them on the basis of the lowest price and quickly regret it continues to grow.
Northern Rail
Transpennine Trains
Caledonian Sleeper
West Midlands Metro
Transport for Wales
and now Transport for London
Do they not talk to each other?
Do they not seek references from previous customers?
Will they ever learn????
Edinburgh also have them for their trams
It’s nothing to do with CAF as the same issue has appeared with the current stock hence the introduction of temporary speed restrictions. The testing of the new CAF units highlighted a generic problem across the fleet.
If it was nothing to do with NAF… sorry, CAF, and the existing fleet have the same issues, then how come the existing fleet are continuing in servive while the new ones are not being introduced? Surely they could all run together?
The speed restrictions have been put in place to allow the existing fleet to continue operating but as I understand it from a news item in Modern Railways it is a technical issue with the signalling system that has been discovered during testing of the CAF trains. The news item is a little unclear but seems to imply that the existing trains have been running rather too close to the track design limits than the signalling allowed and therefore some 5 kph speed changes have been implemented on the existing trains. Implanting these on the new trains requires analysis and software changes hence the delay.
For an order that was supposed to have completed delivery of all 54 trains by December 2023, even CAF only claim to have build 30-odd so far, and I think it’s still in single figures actually delivered to London… I would guess they won’t go in to service until there are sufficient passed fit to use to switch over one complete route.
Ref the speed limits issue.
They run on the same principle as our London Underground Automatic Train Control (ATC) lines. In automatic running for any section of track there is a maximum speed and a target speed which is set at X kph or Y% lower than the limit giving a safety margin for error e.g. for sensor inaccuracy or if track conditions mean the train doesn’t decelerate at the rate expected at a change of speed limit.
As I understand it, it is this that has been highlighted in trial running of the CAF units. They have been less accurate and less predictable at changes of speed, so for example at a change of limit from 50kph to 30kph, given a target speed of 27kph (10% under limit), the B units achieve less than 30k 99% of the time. The CAF units have to be given a target of 25kph to be reasonably confident of them getting to under 30k.