Abbey Line

1902 map showing the route of the Abbey Line with its lost connection to the Midland main line

The line was built in its current form: a branch from Watford to St. Albans. However, the line was at times connected to two other lines. One, the Hatfield and St Albans Railway, opened in 1865 from St. Albans Abbey station to the East Coast main line at Hatfield. Mostly a local route, the construction of the Midland main line ensured that it never became popular with the critical market of passengers to London. It closed to passengers in 1951, part of a cutback of minor routes after the war. The whole route closed to goods in 1964, though a short stub at the Hatfield end lasted until 1968.

During construction of the Midland main line in the 1860s, a branch was laid from near How Wood to the Midland route to carry building materials. Never used by passenger services, Ordnance Survey maps indicate it closed between 1883 and 1898 although the embankment and some bridge abutments remain very visible.[4][5][6][7] As part of a cost-cutting plan in the 1980s, British Rail examined reopening this, with the aim of diverting the branch to the City station and selling off the valuable Abbey station site.

Passenger services are operated by London Northwestern Railway.

Stations on the branch are unstaffed. Some have ticket machines; otherwise tickets must be bought on the train. Passengers starting their journey at Watford Junction, which is staffed, must have a valid ticket prior to boarding the train, in compliance with National Rail conditions of carriage.

The Abbey line is part of the Network Rail Strategic Route 18, SRS 18.10 and is classified as a Rural line.[8]

The line is single track and is electrified at 25 kV AC using overhead line equipment. It has a loading gauge of W6 and a maximum line speed of 50 mph (80 km/h).[8][9]

The service is operated using electric multiple units. London Northwestern Railway runs services with a single Class 319 train, which was acquired in September 2016 by London Midland as part of a set of trains from Thameslink to replace Class 321 units. The Class 321s were in turn were acquired by Abellio ScotRail to operate on Glasgow's suburban rail network.[10]

In addition to Class 321 trains, services on the Abbey Line had previously been operated using Class 313 units. Rarely (and more commonly in the past) a Class 150 diesel multiple unit has been substituted.

Class	Image	Type	Top speed		Number	Cars per unit	Seat layout	Built
			mph	km/h
Class 319		EMU	100	161	4	4	2+3	1987-88

Signalling is under One Train Working[11] (without Train staff) rules, where only one train is allowed on the line at a time. Trains can be moved into Watford Junction yard by a manual ground frame there. On 28 October 2005 its incorrect operation caused an incident with a train not in passenger service.[12]

There is an automatic level crossing outside Watford North. This is operated by a manual plunger for trains heading towards St Albans, and by a treadle towards Watford Junction.

In 2004 a proposal was made by Transport for London for a London Regional Rail Authority to take control over some rail services that extended out of Greater London, including the branch line.[15]

In October 2009 Secretary of State for Transport Lord Adonis announced a plan to increase frequency on the line by allowing Hertfordshire County Council to lease the line from Network Rail and converting it to light rail from 2011. It was hoped that this would be possible for the same amount of subsidy the line received, as the new infrastructure required, such as a passing loop would be cheaper for light rail than heavy rail.[2][16] Longer-term proposals envisaged extensions into Watford town centre via Clarendon Road and High Street, and St Albans city centre,[17] possibly as far as St Albans City railway station, and possible re-instatement of the line to Hatfield.[18]

The light rail plan was cancelled in May 2013, as it was found to be impossible to deliver the scheme within the existing heavy rail subsidy as planned and more complicated than had been expected with disputes over apportionment of ticket revenue and who was responsible for the cost of maintaining structures.[19] Hertfordshire County Council pledged to prepare a more ambitious bid to the DfT for funding for full segregation from the national rail network and extensions on either end rather than to lease the line from Network Rail.

The Busway in Cambridgeshire, an example of a guided busway proposed for the Abbey line[20]

In a Draft Rail Strategy consultation published in June 2015,[21] Hertfordshire County Council highlighted the difficulties presented by single-track operation on the Abbey line, in particular the fact that the maximum service frequency that can be operated is one train per 45 minutes. The report notes that the service pattern makes it difficult to enable interchange connections with other rail services and to offer a "clockface" timetable that is memorable to passengers. Among the solutions evaluated by Hertfordshire are: a proposal to reopen the passing loop at Bricket Wood; running trains which skip certain stations; closing some stations; conversion of the line to light rail operation; and conversion of the line to a guided busway. The passing loop solution would enable a 30-minute service, but the report notes that there would be an additional cost of running the line with two train sets (rather than a single train, as at present), and that it would be "difficult to achieve a favourable business case". The report states that a light rail or busway solution would be quicker to implement and offer higher service frequencies, while still providing sufficient capacity, and concludes that these alternative modes would offer a stronger "business case" than heavy rail. The ABFLY campaign group has criticised the busway proposal, citing environmental concerns about replacing an electric train service with a diesel bus service and rejecting plans to replace the tracks with a concrete busway.[20]

Other proposals considered included adding the Abbey line as a branch of the proposed extension of Crossrail to Milton Keynes Central; this proposal was rejected due to the technical challenges associated with upgrading the Abbey line to accommodate Crossrail trains.[22]

The old passing loop at Bricket Wood, proposed for re-opening to increase services

In May 2020, it was announced that £500,000 of funding from the government's Restoring Your Railway Fund would be available to enable transport planners to develop a business case around the Bricket Wood passing loop proposal. If approved, this scheme would enable an increase in train frequencies, as well as the introduction of a regular "clockface" timetable.[23][24]

Upon winning the West Midlands franchise in 2017, the future operator West Midlands Trains confirmed that new trains would be bought for the Abbey line.[25]