Welwyn Hatfield train passengers will benefit from the enlargement and modernisation of their principal maintenance depot.

The expanded depot at Hornsey in north London, where trains have been serviced since the early days of steam, is now one of the biggest in Britain, larger than 12 football pitches combined.

Govia engineering director Gerry McFadden said: “This enlarged and modernised facility will support the biggest fleet renewal in the history of this part of the Great Northern railway and create fabulous new journeys on to an expanded Thameslink network.

“Built specifically for Siemens to maintain our new Class 700 Thameslink trains, the new building complements the improved existing depot where we care for the Great Northern fleet, and together they create a centre of excellence in engineering.”

The depot will be operated jointly by Govia and its train provider Siemens, and is part of a £300 million investment that also includes new service facilities at Three Bridges, West Sussex.

With new trains due for introduction to the Great Northern route over he next two years, the depot will have to service advanced technology such as climate control and the latest passenger information systems.

Recent improvements at Hornsey include a new maintenance building , a new control room, and better security, such as CCTV and automatic number plate recognition.