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| B23 Rolling Stock - © TfL |
A Freedom of Information request to Transport for London (TfL) has revealed reasons why the new B23 rolling stock, manufactured by CAF for the Docklands Light Railway, has been delayed instead of Spring 2024, as reported in my previous article early this year.
Request ID: FOI-1926-2425
Date published: 10 October 2024
Details of the challenges faced by TfL as part of the test of the new DLR Rolling Stock
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.
What was the cost associated with this delay? Was this cost incurred by the taxpayer?
Any cost or other impacts associated with this delay have yet to be assessed.
What mitigations or sanctions have been put into place to address this?
A series of modifications to the train and signalling have been, or are in the process, of being implemented to address this issue.
There's more information from a previous FOI request about the changes to the DLR services from last month (September).
Request ID: FOI-1784-2425
Date published: 23 September 2024
DLR Speed restrictions and withdrawal of Stratford - Lewisham trains
The peak hour Stratford - Lewisham services on the DLR have been suspended since the start of the week, I asked a member of staff on my train and they said it was due to a large amount of new temporary speed restrictions on the line but they didn't know why they were in place.
What is the reason for these new temporary speed restrictions?
Following a review of our signalling system we identified a pre-existing technical issue, which meant there were a number of places where there was not enough margin between maximum recommended speed and the speed of the trains. For the continued safe operation of the network, we decided to reduce the speed at these locations. The DLR continues to be one of the safest light rail networks in the country.
How long do end to end journeys on all routes now take compared to normal running?
For each service, we have observed the following impact on end-to-end runtime as a result of the introduction of the temporary speed restrictions (TSRs) on the DLR:
|
Service |
Estimated increase in runtime (seconds) |
|
Lewisham-Bank |
73 |
|
Bank-Lewisham |
69 |
|
Beckton-Tower Gateway |
71 |
|
Tower Gateway-Beckton |
73 |
|
Beckton-Canning Town |
17 |
|
Canning Town-Beckton |
44 |
|
Lewisham-Stratford |
123 |
|
Stratford-Lewisham |
114 |
|
Canary Wharf-Stratford |
78 |
|
Stratford-Canary Wharf |
57 |
|
Woolwich Arsenal-Bank |
112 |
|
Bank-Woolwich Arsenal |
151 |
|
Woolwich Arsenal-Stratford International |
114 |
|
Stratford International-Woolwich Arsenal |
158 |
Please note that this is solely based on physical movement time of trains that have not been delayed by the movement of other trains. It does not include the 'dwell' time when trains are stopped in stations. The impact of TSRs may be absorbed by shortening dwell times, but as this will vary significantly by journey, a single figure cannot be given for change in overall end-to-end journey time.
The data is based on observations before and after the implementation of TSRs. Some inferences have been made using signalling data or comparable routes where no observation could be made.
Why has there been no communication to passengers (or seemingly the staff on the trains) about the increased journey times or the withdrawal of peak Stratford - Lewisham services and the reason behind the changes?
Unfortunately we needed to suspend direct peak services between Stratford and Lewisham with customers now needing to change services to complete their journey, which is expected to add up to 2-3 minutes to journey times on this route. We have now increased peak services between Stratford and Canary Wharf to ensure we have sufficient capacity on this busy section of the network. The speed restrictions introduced across the DLR should only have a minimal impact on journey times for the majority of our customers. We worked quickly to understand how these changes would impact customers but needed to fully understand these ahead of any customer communications. We now have a full suite of customer communications, including posters, PA announcements and dot-matrix messaging on the affected route. We have also briefed our entire frontline team who are available to advise and support customers on their journeys.
How long is this expected to last?
The small changes introduced should only have a minimal impact to customer journey times. Further assessment needs to take place before we decide whether any of the changes need to be made permanent.
#Transport for #London Freedom of Information release:
— CLondoner92 (@CLondoner92) August 12, 2024
DLR current fleet availabilityhttps://t.co/oRtmoPlYhn pic.twitter.com/5EQIklXt1J
Unfortunately, we have to wait a while for the new DLR B23 rolling stock to appear in passenger service; at the moment, TfL is still facing issues with their computer systems due to the cyberattacks, which explains why certain people are having issues renewing their concessions, such as the ZIP Oyster card for schoolchildren and the 60+ Oyster card for older people.
