ES News email The latest headlines in your inbox twice a day Monday - Friday plus breaking news updates Enter your email address Continue Please enter an email address Email address is invalid Fill out this field Email address is invalid You already have an account. Please log in Register with your social account or click here to log in I would like to receive lunchtime headlines Monday - Friday plus breaking news alerts, by email Update newsletter preferences

A 90-year-old signalling box at Edgware Road station is finally being disconnected and replaced with new technology that could see trains running a third more frequently on the Circle Line.

The signalling cabin, which is used to ensure the safe running of Tube trains on the Circle and Hammersmith & City lines, has been recognised by the Railway Heritage Designation Advisory Board as an item of historic national interest.

It is finally being withdrawn from service, as the use of mechanical levers is being replaced by a new signalling system that is designed to enable trains to run closer together.

The change will deliver a 33 per cent increase in frequency by the early 2020s.

London Underground's managing director Mark Wild said the cabin, which was built in 1926, will be "honourably retired".

He added: "We aim to provide safe public access to the cabin in the future so that Londoners can share in this unique part of the capital's transport history.

"Upgrading the Circle, District, Hammersmith & City and Metropolitan lines will enable us to increase capacity for millions of our customers.

"At the same time, it's important to us that we recognise the significance of earlier technological advances made by London Underground."

Mike Ashworth, London Underground's design and heritage manager, said: "This unique signalling cabin harks back to the earliest days of London's transport network, being originally built and used by the Metropolitan Railway in 1926. It is a testament to its pioneering design and robustness that it is still in use today.

"Ensuring we understand and preserve the heritage of the world's first underground railway - with all its surprising historic quirks - is key.

"Our new signalling builds upon our tradition of using technology to better operate the Underground system for the benefit of our customers."

Additional reporting by Press Association.