British Rail Class 717

Upon winning the Thameslink, Southern and Great Northern franchise, Govia Thameslink Railway (GTR) announced that it would seek to procure new trains totalling 150 vehicles to replace the then-40-year-old units operating on services to and from . In December 2015, GTR announced that it had selected Siemens to provide this new fleet, originally designated Class 713, The order was finalised in February 2016. A significant difference between Class 717s and the earlier Class 700s is the provision of fold-down emergency doors at both ends of each train. These are required for emergency evacuation of passengers Siemens began testing the Class 717 units in Germany during June 2018. Operation The first unit operated a single preview service in late September 2018, with gradual introduction from the spring of 2019. The final service on Great Northern ran in September 2019, completing the fleet replacement by Class 717 units. == In-cab signalling ==

In September 2021, the installation of European Train Control System (ETCS) on the Class 717 fleet was successfully tested on the Thameslink 'core' route between St Pancras International and Blackfriars stations in central London. The success of the test allowed Govia Thameslink Railway to work towards enabling the use of ETCS in passenger service on the Northern City Line in November 2023, which was followed by the decommissioning and removal of the existing conventional signalling system in May 2025. ETCS is now being introduced to the southern section of the East Coast Main Line as part of the East Coast Digital Programme. ETCS software is being upgraded. On 8 July 2025, unit 717020 ran on the Northern City Line using ETCS Baseline 3, Release 2 (also referred to as version 3.6.0). == Environment ==

Class 717 trains generate electricity through regenerative braking. The trains are also 20% lighter than their predecessors, making them more energy efficient. ==Fleet details==