![](https://static.standard.co.uk/2023/12/27/15/46/Christmas%20rail%20engineering%20work%20projects-xmb57591.jpeg?width=1200&auto=webp)
Signal failures and overrunning Christmas engineering works were causing travel chaos for train passengers in and around London on Wednesday.
Services at the southern end of the line between St Albans and London St Pancras were affected by a fault with the signalling system, while overrunning engineering work caused misery for many Southeastern customers.
Thousands of airline passengers risked missing flights, as East Midlands Railway said the signalling issue was preventing it from running services between London St Pancras and Luton Airport.
Thameslink services to and from the airport are also affected, with many trains cancelled or severely delayed.
Rail services were expected to be disrupted for the rest of Wednesday due to the fault.
Network Rail, which is responsible for rail infrastructure, said the fault was related to work carried out over Christmas by technology company Siemens, to install a new system to control signals on the Midland Main Line.
#EMRUpdate Line closed between Luton and London St Pancras. This is due to a fault with the signaling system. See the website for more info https://t.co/nNe8Z9c6QR pic.twitter.com/8jpIuC0a59
— East Midlands Railway (EMR) (@EastMidRailway) December 27, 2023
Gary Walsh, route director for Network Rail, said: “I am very sorry that our engineering work is affecting passengers today.
“There is a fault with part of the signalling control system which means we need to reduce the number of trains which are able to run.
“Siemens signalling engineers are working to restore a reliable system as soon as possible."
Thameslink issued an alert to passengers which said: “Please do not attempt travel between Bedford and London Bridge until further notice.
“The earlier disruption caused by multiple signal failures has now reoccurred.
![](https://static.standard.co.uk/2023/12/27/15/06/Christmas%20rail%20engineering%20work%20projects-z730ldqv.jpeg)
“Due to the level of disruption, passengers are advised to delay travelling until later.
“If you do decide to travel, you will need to use alternative means on some or all of your journey, and you will need to allow an additional 60 minutes to travel.”
Meanwhile, overrunning engineering works were also causing delays and cancellations to Southeastern train services on Wednesday.
Shortly before 8am, Southeastern warned passengers there was “severe disruption across much of the network” due to “engineering works not finished on time” in the Nunhead area of south-east London.
Lines between the capital and Bromley South, Swanley, Orpington and Sevenoaks were blocked until around 9am.
![](https://static.standard.co.uk/2023/12/27/15/57/Christmas%20rail%20engineering%20work%20projects-f6ip115u.jpeg)
Lines later reopened, but Southeastern said disruption was expected to last until around 11.30am as trains were out of position.
A Network Rail spokesman said: “We’re very sorry to any Southeastern passengers whose journeys were disrupted this morning following planned engineering work overrunning in the Orpington area.
“Train services resumed at 8.27am and disruption is expected to end at 11.30am.
“We’d like to thank passengers for their patience and understanding.”
Paddington railway station was also shut from Christmas Eve to Wednesday, inclusive,due to HS2 engineering work taking place over the festive period.