Watford DC Line

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Watford DC Line
Principal stations

London Euston
(for Northern Line, Victoria Line, Scotrail, Silverlink and Virgin Trains)
South Hampstead
Kilburn High Road
Queen's Park*
Kensal Green*
Willesden Junction*
(for Silverlink North London Line and West London Line)
Stonebridge Park*
Wembley Central*
North Wembley*
South Kenton*
Harrow & Wealdstone*
(for Silverlink)
Headstone Lane
Hatch End
Carpenders Park
(for Silverlink)
Watford High Street
Watford Junction
(for Silverlink and Virgin Trains)
(*also served by Bakerloo Line)

The Watford DC Line is a railway line that runs from London Euston to Watford Junction. Services on the line are currently operated by the railway company Silverlink. The West Coast Main Line runs parallel to the line for the majority of its length, whilst the Bakerloo Line of the London Underground shares the line from Queen's Park to Harrow & Wealdstone. The rolling stock used on the line is Class 313 and Class 508 multiple units. The line is electrified using the third rail system modified by the addition of a fourth central rail needed by London Underground trains equipped for 4-rail electrification - this rail is bonded to the running rail used for traction current return. North of Harrow & Wealdstone the fourth rail has in most places been dropped onto the sleepers.


The services on this line commenced after the opening of the LNWR's Camden to Watford Junction New Line, and were designed to provide additional suburban capacity and enable more outer-suburban services to run non-stop to Euston. It incorporated part of the LNWR's Rickmansworth branch (formerly the Watford and Rickmansworth Railway) between Watford Junction and Watford High Street Junction and part of the original Slow Main Line between Queen's Park station and South Hampstead station; two single-track bored tunnels were built to take the route from South Hampstead to Camden, from where the line reaches Euston station over the Main Line tracks. For the first few years services were steam operated until the completion of electrification on the entire route. Although the operation of the line is mostly self-contained, the connections at Watford Junction and Camden enable the passage of other trains onto or through the line and this has occurred on rare occasions with trains diverted from the West Coast Main Line where circumstances have prevented an alternative diversionary route.

Signalling System

The line was originally opened with conventional semaphore signalling, mechanically-operated from traditional signal boxes at each station; this signalling system remained in use after electrification. The London, Midland and Scottish Railway introduced a new electric signalling system in the early 1930s, enabling trains to be signalled automatically over most of the route; this allowed the abolition of a number of signal boxes on the line. This system was itself replaced by a more conventional signalling system in the 1980s and all remaining signal boxes were abolished around that time. The electric signalling systems also had train-stops provided at appropriate signals so that LER/LU trains could travel over the line without a second man in the cab.

The 1930s system was mostly unique to this line (the LMS had similar but shorter-lived arrangements elsewhere) , using a closely-spaced mixture of automatic and semi-automatic signals along with repeater signals and auxiliary calling-on aspects designed to enable trains to proceed (after a prescribed delay) at low speed past "failed" signals on plain track with no junctions and without taking up time to communicate with a signalman. At times this could result in a nose-to-tail queue of trains once they all reached the location of a genuine failure or mishap protected by the appropriate signals being prevented from showing any kind of "calling-on" indication.

In the early 1980s the LMS system was replaced by a conventional system with far fewer signals and the remaining local signal boxes were abolished. As a consequence the line no longer has the same traffic capacity as before, which in the early 1960s involved headways of less than 2 minutes between Harrow and Wealdstone station and Willesden Junction station, at that time the section of line over which nearly all services passed.

The signal boxes remaining in use in the early 1970s were :-

  • Kilburn High Road (abolished when crossover moved to Down side of station)
  • Queens Park No.3 (abolished after control passed to Willesden)
  • Willesden New Station
  • Stonebridge Power House (abolished after LU Bakerloo Line depot opened)
  • Harrow No.2

[details unavailable further North]

Only Queens Park, Willesden and Harrow were normally staffed for at least part of the day to deal with junction and/or siding traffic; Kilburn High Road and Stonebridge Power House controlled only plain track with crossovers and were normally switched out. In the early 1980s it became necessary to resort to manual control of signalling for a few months after many train-stops were destroyed by dragging gear on a train, their design by then being almost unique to this line as London Underground train-stops are mostly electro-pneumatic devices. By this time the signal boxes at Stonebridge Power House and Kilburn High Road had already been abolished.

In addition to signal-boxes there were also enclosed ground-frames controlling emergency crossovers at other locations; these resembled small signal-boxes of a similar size to a garden shed but were occasionally mistaken to be signalboxes by members of the public.


The original electrification system was similar to that now used by London Underground Ltd (LUL), using a third rail positioned to one side of the running rails and a fourth rail centrally placed; this enabled LER trains to run over the New Line from the start of electrification. By the 1970's this system was anomalous on British Railways and the track and Class 501 rolling stock in use on this line and the North London Line (NLL) were modified to use what was basically a standard 3rd rail system; LUL trains require a 4-rail system so the centre conductor rail is now bonded to the traction current return rail enabling trains with either type of electrical system to use the line. One unintended consequence has been occasional tours by trains previously confined to (what was) the Southern Region of British Railways (SR) and tours of the SR by Class 501. This also permitted both intentional and emergency use of the line by other 3-rail-capable trains as has occurred with current use of the line by Class 313 trains and past emergency working by Class 416 trains diverted from the North London Line and more recent use of Class 508 trains in temporary substitution for unavailable Class 313 trains.

Passenger Services

Current passenger services over the DC line use the following routes :-

  • Watford Junction to Euston (but advertised as South Hampstead from Watford Junction in order to avoid people using the service to travel to Euston)
  • Harrow and Wealdstone (or Stonebridge Park) to LUL Bakerloo Line via Queens Park

Past services have included:-

  • Watford Junction (or Bushey and Oxhey or Harrow and Wealdstone) to Broad Street (later Liverpool Street) via Hampstead Heath or Primrose Hill
  • Croxley Green to Euston or Broad Street
  • Croxley Green to Watford Junction
  • Watford Junction (or Bushey and Oxhey) to LUL Bakerloo Line via Queens Park

When the south curve of the triangular junction existed at Bushey a small number of trains entered or left the service directly to/from Croxley depot (now demolished) which was shared by LUL and BR trains.


The original plan involved the construction of a curve to link Rickmansworth (Church Street) to the Euston main line. A new line would then be run south to Wembley, after which it would pass under the main line and run on the east side to Euston, terminating in a loop.

Cost-cutting resulted in the loop being dropped; instead, services terminated in Euston's main platforms, or ran along the North London Railway to Broad Street. Pressure from various local groups resulted in an additional curve being built near Bushey, enabling trains to run north to Watford Junction, Rickmansworth and Croxley Green. In 1917, LER Bakerloo Line services were extended over the New Line from Queen's Park station to Watford Junction.


Bakerloo Line services were cut back in stages and ceased north of Stonebridge Park station in 1982; in 1984 they were restored as far as Harrow and Wealdstone but the 4th-rail is not currently installed at many locations north of there.

The Croxley Green branch fell into disuse in the 1990s, and is currently derelict. It is planned to divert the Metropolitan Line over the branch and on to Watford Junction (for more information see Croxley Rail Link). Some clearance or preparatory work has been reported [1] as having occurred in late 2006.


  1. uk.railway internet newsgroup


From November 2007 the line will be controlled by Transport for London as part of the London Overground. It is tentatively planned that a re-structuring will see DC trains withdrawn between Primrose Hill Junction and Euston, and the Queens Park to Watford Junction section transferred to the Bakerloo Line (see page 7-9). In December 2006, the Mayor of London Ken Livingstone announced that TfL would also take full management control of all the Watford DC Line stations except Willesden Junction as part of the new Overground service - the main improvements being the provision of staff during opening hours, the installation of automatic ticket gates and in the longer term, station refurbishment up to the same standards as on the Tube network.

The London Overground may then operate a passenger service from Queens Park to Primrose Hill Junction, serving South Hampstead and Kilburn High Road; from there using a freight line to Camden Road; and onwards to Stratford via the North London Line (page 9)

Railway lines in London:
North London:  Dudding Hill Line   Hertford Loop Line   Gospel Oak-Barking Line   North London Line   Northern City Line   Lea Valley Lines  
 St Albans Branch Line   Thameslink   Watford DC Line
East London:  Romford-Upminster Line
South London:  Bexleyheath Line   Bromley North Line   Catford Loop Line   Greenwich Line   Dartford Loop Line
 Hayes Line   Hounslow Loop Line   South London Lines   Tattenham Corner Line   Thameslink
West London:  West London Line
Proposed network: London Overground