19th century The first of the tunnel bores was built as part of the construction of the
Great Northern Railway between 1851 and 1852, The original tunnel now forms the central of three parallel bores. A second bore to the east was built in 1878, and a third one to the west in 1892. The Gasworks Tunnel's construction was particularly challenging due to the steep gradient and narrow clearances of the railway. On 29 December 1893, a passenger train travelling from King's Cross to
Hatfield collided with seven empty coaches that were being shunted into the station to be used in an express service. In his report to the
Board of Trade on the accident, railway engineer
Horatio Arthur Yorke concluded that it was caused by an unexplained derailment of goods coaches, but that it was exacerbated by poor arrangements for shunting through the tunnels, which he called "hardly satisfactory".
20th century On 10 December 1900, an express train travelling from
Leeds to King's Cross became stuck in the Gasworks Tunnel due to rail slip, which then delayed other trains. The train managed to restart itself without external intervention. During World War II, some express services ran by the
London and North Eastern Railway were so long that they stretched into the tunnel when the locomotive stopped at the buffers at King's Cross, including trains of more than twenty cars. On 4 February 1945, the
King's Cross railway accident occurred when a heavy train of 17 coaches weighing approximately hauled by a
Class A4 locomotive was unable to achieve the climb through the Gasworks Tunnel, slipped to a standstill and rolled back into the station, killing two passengers and injuring 25 others.
British Rail carried out electrification of the southern part of the East Coast Main Line with
overhead lines from London King's Cross to between 1976 and 1977. This was authorised in 1971 for the benefit of London suburban services as part of the
Great Northern Suburban Electrification Project. In 1977, the Gasworks Tunnel's eastern bore was taken out of use and its
track bed removed. and works to improve headroom at the southern end of the tunnel. At the time of the eastern bore's closure, it had only ever been used by steam trains, and this had caused significant
soot build-up in the Gasworks Tunnel which had to be removed during its renovation and reinstatement.
21st century As part of a larger modernisation program of London King's Cross and the East Coast Main Line, the eastern bore of the Gasworks Tunnel was reopened. The reopened bore meant that the number of tracks before the station throat increased from four to six, and this allowed for a 50% increase in capacity at King's Cross. Because the Gasworks Tunnel sits below residential property, the track bed was built with elastic mats that soaked up vibrations. In January 2024, the Gasworks Tunnel and the neighbouring
Copenhagen Tunnel became the first in the country to have new signal-boosting technology fitted inside. This stops devices from losing signal and allows passengers to continue calls while travelling through the Gasworks Tunnel. The upgrade was funded entirely by the LNER. , the operators travelling into King's Cross via the Gasworks Tunnel include
Grand Central,
Great Northern and Thameslink,
Hull Trains,
London North Eastern Railway, and
Lumo. == See also ==