Pancras International station. Trains diverging from the Great Northern Route at Belle Isle will 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. Eventually 75% of the GN fleet will be Class 700 units. Services The Great Northern off-peak service pattern, with frequencies in trains per hour (tph), consists of the following: Rolling stock As of 2021, the Great Northern fleet consists of and , the former operating services from London King's Cross and the latter from Moorgate. also operate on the route on Thameslink services. Prior to the introduction of Class 387s and Class 717s in 2016 and 2019 respectively, , , , and were used. Of these, Class 365s lasted until 15 May 2021, at which point they were replaced by Gatwick Express Class 387/2 units which were being used by Southern while the service was suspended. Current fleet Past fleet Trains formerly used on the Great Northern Route include, but are not limited to, the following: Future developments East-West (Varsity) line The Varsity Line connected with via and ("Varsity" being slang for "University", those termini being major university towns). It was closed in 1968 but there are now plans to restore this route. References Further reading External links Railway lines in the East of England Railway lines in London Transport in Hertfordshire Transport in Bedfordshire Transport in Cambridgeshire Rail transport in Norfolk Standard gauge railways in England Great Northern Railway (Great Britain) Rail transport in Cambridge