The Docklands Light Railway often plays second fiddle to its larger subterranean cousin, the London Underground. Known colloquially as the DLR, the line was originally built to provide a modest public transport system for the growing London Docklands development, with a dozen trains serving a route just 7.5 miles (12 kilometres) in length. However, it has since grown dramatically due to the ever increasing demand for transportation in East London, and its driverless trains now serve over 30 stops with interchanges to seven Underground stations and seven National Rail stations.

The Beginning

The area of east London known as Docklands began with the construction of docks on the Isle of Dogs in 1802, the first enclosed dock to be built off the River Thames. Soon, the docks spread off the Island¹, and eventually stretched from St Katherine's Dock by Tower Bridge to the Royal Docks near the present-day London City Airport. The area thrived for more than a century, supplying the surrounding area with a steady source of income, and a great deal of development took place². However, this success was too good to last indefinitely, and in 1960 the docks began to struggle as container shipping brought bigger boats which made use of large coastal ports instead of the comparatively shallow docks. By the 1980s, the docks were in complete disuse and the area became severely neglected.

In 1982, the government decided to redevelop the area, and encouraged construction and renovation on the disused 'brown-field' sites. This was done via the formation of the London Docklands Development Company (LDDC) by Margaret Thatcher's government, with the LDDC being responsible for the construction of the many of the buildings in the area, including Canary Wharf, which was built by Canadian millionaire Paul Reichman in 1986. Thatcher associated herself closely with the project, and will forever be connected with the grief caused in the Docklands area³ and the recession and following boom in house prices.

To allow successful regeneration, the area would need a new public transport system, and Docklands contained many disused railway lines which provided the space and architecture for a brand new overground light railway system. Work began in 1984 with the construction of three branches, from Tower Gateway, Stratford and Island Gardens, the £7 million system was ready for use three years later, and was officially opened by Queen Elizabeth II on 31 July, 1987.

History of the Docklands Railways

The original DLR section between Shadwell and West India Quay operates along a viaduct of the disused London & Blackwall Railway (L&BR) which was built to serve the Docklands, and which opened in 1840. The L&BR started life as a line from the City to Blackwall, but was soon extended to cope with the success of the docks at the time. Soon there were lines from Limehouse to Stratford, from Poplar to North Greenwich, and another all the way out to Barking. The East & West India Docks & Birmingham Junction Railway opened in 1852 from Camden to the Isle of Dogs via Bow, and was later renamed the North London Railway (NLR). Meanwhile the existing Eastern Counties & Thames Junction Railway (EC&TJR) ran between Stratford and Thames Wharf, and was also extended to serve Beckton and North Woolwich, with the latter branch being partly diverted into a tunnel to accommodate new docks and waterways.

With the decline of the docks, combined with the repeated bombing of Poplar station during World War Two, the railway began to disappear until the only services left in 1980 were the former L&BR route out to Barking, and the partially underground line from North Woolwich, now part of the North London line. When the DLR was built, there were many unused sections ready for use, and so in 1987 the original line incorporated the following routes:

• The L&BR viaduct between Fenchurch Street and Limehouse, which is now also used by c2c, followed by the disused L&BR viaduct to Poplar. This formed the DLR branch to Tower Gateway.
• The NLR line from Poplar to Bow followed by the L&BR and EC&TJR lines from Bow to Stratford, where a disused platform was used. This formed the DLR branch to Stratford.
• The L&BR viaduct between Mudchute and North Greenwich, forming the southern end of the original Island Gardens branch of the DLR.

When the line was extended from Crossharbour towards Lewisham, a new section of line was built to serve Mudchute and Island Gardens, making the old viaduct there disused once more, and leaving the two old stations abandoned. However, the extension from Poplar to Beckton made use of the old EC&TJR route between Cyprus and Beckton, and the new King George V extension follows the same route that the EC&TJR North Woolwich branch took between Canning Town and Silvertown before the dock development lead to it being rerouted into a tunnel. As mentioned, the North London line now uses this tunnel, and it is ironic that its presence in Woolwich is threatened by a light railway making use of the very route it replaced.

Structure

The DLR consists of underground, overground and elevated sections of line, with the latter making up the bulk of the line. The line runs in a short tunnel from Bank onto the lines from Tower Gateway, while another tunnel carries the line under the Thames between Mudchute and Greenwich. Both sets of tunnels contain walkways for emergency egress. When the tunnels to Bank opened, the rolling stock had to be replaced for safety reasons, as the original trains did not have doors at the ends of the cars. The Bank route has also caused problems in icy weather, when trains have been unable to make it up the slope onto the main viaduct out of Tower Gateway.

The elevated sections are mainly on old railway viaducts, and include the line from Tower Gateway to Poplar and the line south from the delta junction towards Mudchute, where it then descends into the cut-and-cover tunnel before passing through a tube under the Thames. While the Stratford branch runs along an ordinary overground route for most of its course, the rest of the DLR consists of a mixture of viaducts, cuttings and embankments depending on the surrounding elevations and local requirements. The line even runs in the middle of a road between the stations at Beckton Park and Cyprus, both of which lie in the middle of road junctions. In a stark contrast to the London Underground, the views from the line are often rather good.

The tracks used by the DLR are very similar to those used on the Underground, with a third rail providing power that is generated at local substations⁴ powered by local electricity companies. The stations at Bank, Canning Town and Stratford are contained within the London Underground complexes, but otherwise the DLR stations have no barriers. The platforms at stations are often accessed separately, with lifts and staircases often being the only means available. The platforms are level with the train floors, meaning that disabled access is usually easy. Most stations are left unmanned except for the busier stops, the London Underground stations, and the two other subterranean stops at Island Gardens and Cutty Sark. The line has depots at Poplar and Beckton.

Operation

DLR trains are fully automatic and are operated entirely by an onboard computer system linked to a central control room, giving the system its tag as 'the biggest toy train set in the country'. The control system monitors all the relative positions and speeds from the onboard computer signals and trackside monitoring systems, and then sends data to the trains to ensure that safe distances are maintained. Since there is no driver's position, passengers can sit right at the front and back of the train, both of which are fully glazed⁵. The train is manned by a Passenger Service Agent⁶ (PSA), whose job is to check tickets, make announcements⁷, open and close the doors at stops, and take over control if there are any problems with the system. The trains also use Automatic Train Protection, a system which prevents two trains from occupying the same segment of line, and also stops the PSA from passing through stop signals if they have to take control of the train. Trains vary their speed automatically to ensure that services arrive on time, and are able to run at up to 50 miles per hour (80 kilometres per hour). Passengers are counted in and out of stations using infrared detection systems to ensure that no-one is lost in the system.

Regular services run from Bank towards Lewisham and via Canning Town towards King George V, while trains from Tower Gateway serve the line to Beckton via Canning Town. Trains also run from Lewisham to Stratford via Poplar, although it is notable that some trains from Stratford only go as far as Crossharbour, and other services also operate at peak times. Platforms are often named after the main destination as opposed to being numbered. The line originally ran articulated one-car trains, but due to the increasing demand the line was upgraded so that two-car trains began to run in 1991. Further work was begun in 2005 on the line between the City and Lewisham to allow three-car trains to run.

Interchanges and Connections

Although London's successful bid for the 2012 Olympics has led to plans for new overground transit systems and other extensions around the DLR area, the line already has connections to a range of services. The most important interchange on the system is in fact Poplar station, as all DLR routes run through here. The original terminus at Tower Gateway lies a short walk from both Fenchurch Street railway station and Tower Hill tube station, which serves the Circle and District lines.

The newer western terminus at Bank lies about half of the way along the claustrophobic passages between Bank and Monument, with the surrounding station complex serving the Central, Waterloo & City, Northern, Circle and District lines. The next station after the two termini in the City is Shadwell, which lies a short walk from the East London line station of the same name. However, the ticketing system allows this interchange to count as one journey, and allows you to pick up a pie from the local Pie & Mash shop on the way. The next station is also an interchange, with Limehouse DLR being connected to the mainline station of the same name, which serves the line out of Fenchurch Street towards Shoeburyness.

The DLR links to the Jubilee line at Canary Wharf, Canning Town and Stratford, with the latter also serving the Central line and the 'one' railways line out of Liverpool Street. Heron Quays also has an underground walkway linking to the Jubilee line station at Canary Wharf, and is in fact closer to the Jubilee line than Canary Wharf DLR. Stratford, Canning Town and Custom House stations are also served by the Silverlink North London line, although this may soon be cut back to terminate at Stratford. A final link to the Underground is provided at Bow Church, which lies 200m from Bow Road on the District and Hammersmith & City lines.

Both Greenwich and Lewisham DLR stations lie next to mainline stations, and some South Eastern mainline services out of Charing Cross, Cannon Street and London Bridge pass through Greenwich station, while others join those from Victoria to pass through Lewisham station. A future extension of the DLR will reach Woolwich Arsenal mainline station, which also lies on parts of these overground lines. This extension will also provide better access to London City Airport station, which allows easy connections to domestic and international flights. Two final interchanges are found at Island Gardens, where passengers can leave the DLR to use the Greenwich foot tunnel, and at Cutty Sark, where passengers can change for the riverboat services.

Extensions

Despite having been a brand new project as recently as 1984, the DLR has been continually expanding due to the ever-increasing demands on the system. As soon as the original line had opened, improvements began on the existing stations to increase the line's capacity to two-car trains. Meanwhile, work was started on an extension to Bank Underground station, providing a separate terminus to that at Tower Gateway. The Bank extension would drop steeply away from the viaduct, but would then have to pass through a tunnel under the City of London, and so tunnelling work began in 1988, costing twice the railway's original cost. The line has since expanded constantly, and the following extensions now exist, are under construction, or are planned and likely to go ahead:

• Royal Mint Street Junction⁸ to Bank.
  • Cost: £149 million.
  • Completion date: 1991.
• Poplar to Beckton
  • Cost: £224 million.
  • Completion date: 1994.
• Mudchute⁹ to Lewisham
  • Cost: £200 million.
  • Completion date: 1999.
• Canning Town to King George V
  • Cost: £140 million.
  • Completion date: 2005.
• King George V to Woolwich Arsenal
  • Cost: £150 million.
  • Completion date: 2009.
• Canning Town to Stratford International¹⁰
  • Cost: No estimate.
  • Estimated Completion date: 2010.
• Gallions Reach to Dagenham Dock
  • Cost: £250 million.
  • Estimated Completion date: 2015.

In addition to these extensions, there have been other changes made to existing sections of line. In 1991, Canary Wharf station opened just south of West India Quay to serve the growing population there, and in 1996 another new station was opened at Pudding Mill Lane just south of Stratford. Meanwhile, various stations have been renovated, and the extensions have led to changes being made to the line itself. This has included the rebuilding of the main 'delta junction', where the four lines meet near to West India Quay, to include a line direct from Westferry towards the Beckton branch.