Thameslink trains across Hertfordshire are set to be upgraded as part of a £32.7 million investment in the fleet.

A contract has been signed for the 115-strong Thameslink fleet to be upgraded to the latest specification of the European Train Control System (ETCS), which replaces conventional trackside signals with state-of-the-art digital signalling. The new system provides continuous, real-time information to the driver's cab.

According to a Thameslink spokesperson, "the technology will mean more reliable and greener services for passengers and freight".

A five-year contract to carry out the upgrades as part of the East Coast Digital Programme (ECDP) was signed by Cross London Trains, the Department for Transport, Govia Thameslink Railway, Network Rail and Siemens Mobility.

The upgrades will be made to Thameslink's class 700 units, seen on commuter routes throughout Hertfordshire.

Software design and development for the upgrade will take place from this summer, with a programme of testing and commissioning set to get underway from 2024.

The entire fleet will then be upgraded in 2026, following the completion of safety approvals and the validation process.

Ed Akers, ECDP principal programme sponsor at Network Rail, said: “Preparing and upgrading trains is the biggest challenge ECDP faces, due to the complexity involved with many partners and commercial arrangements.

"We’ve worked hard to secure this new contract for the largest passenger fleet on ECDP and all parties will be working collaboratively to ensure effective delivery of these upgrades.”

Huw Merriman, the rail minister, said: “This transformational programme is already creating the next-generation railway, and upgrading Thameslink’s trains will mean even more dependable and greener services for both passengers and freight.

“With £1billion invested into the programme we remain committed to revolutionising the network for years to come.”