Great Northern route

The Great Northern route is formed of the Northern City Line, Hertford Loop line, the southern section of the East Coast Main Line between London Kings Cross and Peterborough, the Cambridge line, and the Fen line. Since Greater Anglia withdrew its services to King's Lynn in May 2023, Govia Thameslink Railway has been the sole operator of the entire route except between London Kings Cross and Peterborough, and between Cambridge and Ely. The route serves 55 stations. == History ==

The term Great Northern is related to the Great Northern Railway, the original builders of the line. The July 1922 Bradshaw's Railway Guide stated a typical rail service on the Cambridge Line as follows: • to - Six stopping and two (three on Saturday) semi-fast services from Monday to Saturday, one northbound and two southbound stopping services on Sunday. The fastest service took about 1 hour 30 minutes. • London King's Cross to - Two (three on Wednesday) additional services from Monday to Saturday, one additional service on Sunday. • London King's Cross to - Seven additional services from Monday to Saturday. • London King's Cross to - Three additional services from Monday to Saturday. The last service on Wednesday ran past midnight into Thursday morning. Since the 1960s, Great Northern has been used to describe the suburban part of the East Coast Main Line, south of and south of . The Great Northern Railway had proposed electrification of part of the line in 1903, but it was not until 1971 that a scheme to electrify the line from and was authorised. The Inner Suburban Lines to and were electrified in 1976 with EMUs. In 1978 the electrification was complete to Royston with EMUs providing the service. The route was then promoted as the Great Northern Electrics. With the further electrification of the East Coast Main Line between 1986 and 1988, electric services could be extended to Peterborough and the outer suburban service was changed from to , some of which were cascaded from the newly created Thameslink route, with the remainder newly built. In 1984 it was decided to electrify the line between Royston and Shepreth Branch Junction, a junction on the West Anglia Main Line north of , allowing the reinstatement of through services to from London King's Cross via the East Coast Main Line, which was faster than the conventional route from via the West Anglia Main Line. This electrification was completed in 1988. Later the track between these points was also upgraded with welded joint track instead of the jointed track that had existed, and the maximum line speed was raised to 90 mph. Rapid growth on the route, especially on the Cambridge Line resulted in consultation on a new service pattern, which was then implemented at the timetable change in Spring 2009. During the peak hours, the route is now saturated and can support no further service improvements. Hitchin Flyover Together with the two-track Digswell Viaduct (Welwyn Viaduct) some ten miles to the south, the flat junction just north of was a major bottleneck, as northbound trains diverging from the East Coast Main Line towards Letchworth and thence to Cambridge had to cross one northbound (fast) line and two southbound (fast and slow) lines to access the Cambridge Line. Proposals as part of the original electrification work envisaged a new underpass here and land was set aside for its construction. However, budgetary constraints forced this part of the programme to be abandoned. The land stood empty for many years, but has since been used to provide new housing. A new plan and subsequent application for an order to build a flyover was approved, and construction was completed in June 2013. The scheme has created a new single-track line that diverges from the northbound slow line at a new junction just beyond Hitchin station, using a short embankment section of the former Bedford to Hitchin Line, a section of which was cleared of vegetation and made progressively higher, to form a short ramp. The track is carried over the East Coast Main Line on a newly constructed viaduct and onto a new embankment to join the present Cambridge Line at the newly created Hitchin East Junction, closer to Letchworth. Although this takes trains over a longer distance, it removes the need for them to dwell at Hitchin – sometimes for several minutes – awaiting a path across the tracks of the main London-Peterborough route, thus decreasing the overall journey time to Cambridge in many instances. The scheme improves the punctuality and reliability of both the London-Cambridge and London-Peterborough routes, because Peterborough-bound stopping trains are no longer delayed if running closely behind a Cambridge service being held at Hitchin waiting to cross the flat junction. Thameslink programme As part of the Thameslink Programme, the Great Northern Route has been connected to the existing Thameslink route via a new junction at Belle Isle (south of the High Speed 1 flyover, just north of London King's Cross). Two single-bore tunnels (known as the Canal Tunnels) were driven from here to the low-level platforms at during the 'St Pancras Box' phase of the redevelopment works that created St Pancras International station. Trains diverging from the Great Northern Route at Belle Isle join the 'core' St Pancras - - - section of the existing Thameslink route and then serve stations across Surrey, East Sussex, Kent, and West Sussex. On 6 November 2017 the first Thameslink Programme units entered service on the Great Northern route. 700128 worked the 0656 Peterborough – London King's Cross and 1812 return, while 700125 worked the 0733 Peterborough – London King's Cross and 1742 return. == Services ==

Off-peak The Great Northern MondayFriday off-peak service pattern, as of December 2025, with frequencies in trains per hour (tph), consists of the following: ==Rolling stock==

Govia Thameslink Railway The majority of Great Northern services are operated with Electrostar units. On 12 March 2024 it was announced that Great Northern would lease 30 Class 379 units from Porterbrook. These were introduced for their services to Letchworth in February 2025, which replaced Class 387 units in order to allow them to be transferred to Southern. Past fleet Trains formerly used on the Great Northern Route include, but are not limited to, the following: ==Future developments==

Cambridge South railway station under construction in 2024. A station to the south of Cambridge was first proposed in 2017, and although its application to New Stations Fund 2 that year was unsuccessful, the November 2017 budget allocated it £5 million in funding. The station, called Cambridge South, is situated between Foxton and Cambridge on the Cambridge line, and will serve the Cambridge Biomedical Campus and the wider Trumpington area. The station is set to open in early 2026, which is a delay from the originally proposed date of late 2025. The station will be managed by Greater Anglia and will be served by all Greater Anglia, Great Northern, Thameslink and CrossCountry services passing through the station when it opens. Additionally, East West Rail services will also call at Cambridge South in the future, once East West Rail has been built to Cambridge and opened. East West Rail The route of East West Rail, the new railway linking the cities of Oxford and Cambridge, will intersect with the East Coast Main Line at Tempsford in Bedfordshire, where a new station will be built to serve both routes. This has led to worry from local residents, particularly due to a report by East West Rail that the population of the village could grow from 600 to 44,000. As a result of extra funding in the 2024 budget, East West Rail will deliver the station five years earlier than planned, allowing passengers on the East Coast Main Line to access the station before it opens as part of the East West Rail route. Both Cambridge South and Cambridge stations on the Cambridge line will also be served by East West Rail, the –Cambridge section of which is in consultation as of 2025. The current plan for the route will include a grade-separated junction with the line at Hauxton, between Foxton and Cambridge. This will include improvements to Hauxton level crossing. East West Rail confirmed in their 2021 consultation that the Cambridge line will remain double-tracked between this junction and Shepreth Junction, where the line will be quadrupled to run alongside the West Anglia Main Line as far as Cambridge. TfL wants to increase the number of trains from two trains per hour to four trains per hour, standardise fares across the route, serve a 21,000 home development at Crews Hill, and boost growth in North London and Hertfordshire. The takeover could occur in Autumn 2027, after Govia Thameslink Railway's franchise ends, if approval is given by DfT; however, the Overground services would use the existing Class 717 stock. == References ==