Great Northern route
The Great Northern 'route, formerly known as Great Northern Electrics', is a suburban rail route in London and the East of England. The route consists of services on the southern end of the East Coast Main Line, which is the main railway link between the cities of London and Edinburgh, as well as its associated branches, including the Cambridge line, Fen line, Hertford Loop line, and Northern City Line.
The route is currently operated by Great Northern, which is one brand under the umbrella of Govia Thameslink Railway. Services originating at London King's Cross operate to Peterborough, Letchworth Garden City, Cambridge, Ely, and Kings Lynn, whereas services originating at Moorgate operate to Welwyn Garden City, Hertford North, Gordon Hill, and Stevenage.
The route forms a major commuter route into London from Hertfordshire, Cambridgeshire, and eastern Bedfordshire; ridership has grown rapidly over recent years.
Passenger services on the Great Northern route, along with all others currently operated by Govia Thameslink Railway, are due to transfer to the publicly owned operator Thameslink Southern Great Northern on 31 May 2026.
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.At privatisation the services became part of West Anglia Great Northern, becoming their sole route in 2004 when the West Anglia services were transferred to 'one'. In April 2006 the services became the responsibility of First Capital Connect. In September 2014, the Department for Transport transferred the new Thameslink, Southern and Great Northern franchise to Govia Thameslink Railway.
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 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 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.
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. The route between Hertford and Langley Junction, south of, was also electrified but not regularly used by electric trains until 1979, when one Moorgate - Hertford service per hour was extended to ; prior to this DMUs provided an infrequent service over this route, running between Hertford and / Peterborough. From 1979 until 1987 DMUs provided the service between Hitchin and Huntingdon/Peterborough. DMUs also provided a shuttle service between Royston and Cambridge between 1978 and 1988, connecting with the electric trains and replacing the former through Cambridge buffet expresses between Kings Cross and the university city.
In 1982 Watton-at-Stone station was reopened between Hertford and Stevenage. A new station also opened at in 1986.
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 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 line and two southbound 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. Two single-bore 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, consists of the following:| Route | Calling at | |
| London King's Cross to | 1 | Cambridge, Cambridge North, Waterbeach, Ely,,, |
| to | 1 | Cambridge, Cambridge North, Waterbeach |
| London King's Cross to Cambridge | 1 | Finsbury Park, Alexandra Palace, Potters Bar, Hatfield, Welwyn Garden City, Welwyn North, Knebworth, Stevenage, Hitchin, Letchworth Garden City, Baldock, Royston, Meldreth, Shepreth, Foxton |
| London King's Cross to Letchworth Garden City | 1 | Finsbury Park, Alexandra Palace, Potters Bar, Hatfield, Welwyn Garden City, Welwyn North, Knebworth, Stevenage, Hitchin |
| to Welwyn Garden City | 2 | ,,,, Finsbury Park,,, Alexandra Palace,,,,, Potters Bar,,, Hatfield |
| Moorgate to Stevenage via | 2 | Old Street, Essex Road, Highbury & Islington, Drayton Park, Finsbury Park, Harringay, Hornsey, Alexandra Palace,,,,,,,,,,, |