Docklands Light Railway

The Docklands Light Railway (the DLR) is an automated light metro system opened in 1987 to serve the redeveloped Docklands area of London. It reaches north to Stratford, south to Lewisham, west to and  in the City of London financial district, and east to Beckton, London City Airport and Woolwich Arsenal.

The system uses minimal staffing on trains and at major interchange stations; the four sub-surface stations are staffed to comply with underground station requirements. Similar proposals have been made for the adjacent system, the Tube.

The DLR is operated under a concession awarded by Transport for London to Serco Docklands, part of the Serco Group. The system is owned by Docklands Light Railway Ltd, part of the London Rail division of Transport for London. In 2011 the DLR carried over 86 million passengers. It has been extended several times and further extensions are planned.

Origins and development
The docks immediately east of London began to decline in the early 1960s as cargo became containerised. The opening of the Tilbury container docks, further east in Essex, rendered them redundant and in 1980 the government gained control. The Jubilee line of the London Underground opened in 1979 from to  as the first stage of an intended cross-town line to south-east London. Land at Ludgate Circus and Lewisham had been reserved for the second stage, a station partly constructed in the City and buildings at Cannon Street modified, but rising costs and the low level of development in Docklands then envisaged not justifying the railway led to the project's indefinite postponement in the early 1980s.

The London Docklands Development Corporation (LDDC), needing to provide public transport cheaply for the former docks area to stimulate regeneration, considered several proposals and chose a light rail scheme using dock railway infrastructure to link the West India Docks to Tower Hill and to run alongside the Great Eastern line out of London to a northern terminus at, where a disused bay platform at the west of the station was available for interchange with the Central Line and main line. Stratford was preferred to the alternative, which would have involved street running trams and was at variance with the concept of a fully automated railway. The growth brought to Docklands enabled the Jubilee Line to be extended in 1999 to east London by a more southerly route than originally proposed, through Surrey Quays, Canary Wharf and the Greenwich Peninsula (which was the next regeneration area) to Stratford.

The contract for the initial system was awarded to GEC Mowlem in 1984 and the system was constructed from 1985 to 1987 at a cost of £77 million. The line was officially opened by Queen Elizabeth II on 30 July 1987, and passenger services began on 31 August.

Initial system (1987–1990)
The initial system comprised two routes, from and Stratford to. Most was elevated on disused railway viaducts or new concrete viaducts, with use of disused surface railway formation between Poplar and Stratford. The trains are fully automated, controlled by computer, and have no driver; a Passenger Service Agent (PSA) on each train, originally referred to as a "Train Captain", is responsible for patrolling the train, checking tickets, making announcements and controlling the doors. PSAs can take control of the train in circumstances including equipment failure and emergencies.

The system was lightweight, with stations designed for trains of only a single articulated vehicle. The three branches totalled 8 mi, had 15 stations, and were connected by a flat triangular junction near. Services ran from Tower Gateway to Island Gardens and from Stratford to Island Gardens; the north side of the junction was used only for access to the depot at Poplar. The stations were mostly of a common design and constructed from standard components. A common feature was a short half-cylindrical glazed blue canopy. All stations were above ground and were generally unstaffed, unlike extension stations built below ground (for example, Cutty Sark (DLR) and ) which are required by law to be staffed in case evacuation is needed.

First stage extensions (1991–1994)
The initial system had a relatively low capacity, but the Docklands area very quickly developed into a major financial centre and employment zone, increasing traffic. In particular Tower Gateway, at the edge of the City of London, attracted criticism for its poor connections (it did not connect with Tower Hill or Fenchurch Street, the two closest and most useful potential connections). The criticism was partly because the system experienced higher-than-expected usage. Plans were developed before the system opened to extend it to in the west and Beckton in the east. Stations and trains were extended to two-unit length, and the system was expanded into the heart of the City of London to through a tunnel, opening in 1991. This extension left on a stub. The original trains, not suitable for use underground, were operated for a time on the above-ground sections only, and later were sold (see the Rolling Stock section below, and the main article Docklands Light Railway rolling stock).

As the Canary Wharf office complex grew, station was redeveloped from a small wayside station to a large one with six platforms serving three tracks and a large overall roof, fully integrated into the malls below the office towers. The original station was not completed and was dismantled before the line opened, although trains stopped at its location.

The east of Docklands needed better transport connections to encourage development, and a fourth branch was opened in 1994, from to  via  transport interchange, along the north side of the Royal Docks complex. Initially it was thought likely to be underutilised, due to sparse development. Several proposals were made for the Blackwall area. As part of this extension, one side of the original flat triangular junction was replaced by a grade-separated junction west of Poplar, and a new grade-separated junction was built at the divergence of the Stratford and Beckton lines east of Poplar. Poplar was rebuilt to give cross-platform interchange between the Stratford and Beckton lines.

Second stage extensions (1996–1999)
Early on, Lewisham London Borough Council commissioned a feasibility study into extending the system under the River Thames. This led the council to advocate an extension to Greenwich, Deptford and Lewisham. In its early days, the system had been criticised by some experts as being "the wrong type of system for Docklands' needs", in comparison with the Underground line proposed in the 1980s. The ambitions of the operators were supported by politicians in Parliament, including Labour Deputy Prime Minister John Prescott, and Lord Whitty, and by 1996 construction work had begun.

On 3 December 1999 the Lewisham extension opened. It left the Island Gardens route south of the Crossharbour turn-back sidings, dropped gently to where a street-level station replaced the high-level one on the former London & Blackwall Railway viaduct, and entered a tunnel following the line of the viaduct to a shallow subsurface station at, accessed by stairs or a lift. It crossed under the Thames to in the centre of Greenwich, and surfaced at Greenwich station with cross-platform interchange between the northbound track and the London-bound main line. The line snaked on a concrete viaduct to, before descending to at street level, close to Lewisham town centre, terminating in two platforms between and below the main-line platforms at Lewisham near the shopping centre, with buses stopping outside the station. The extension quickly proved profitable.

Third stage extensions and enhancements (2004–2009)
The next developments were aided by a five-year programme of investment for public transport across London that was unveiled by Mayor of London Ken Livingstone on 12 October 2004. On 2 December 2005, an eastward branch along the approximate route of the former Eastern Counties and Thames Junction Railway on the southern side of the Royal Docks complex opened from Canning Town to via.

A further extension from to Woolwich Arsenal opened on 10 January 2009, providing interchange with the North Kent main line, close to the planned future stop on the Crossrail line to Abbey Wood via West India and Royal Docks, met by Private Finance Initiative funding. Construction began in June 2005, the same month that the contracts were finalised, and the tunnels were completed on 23 July 2007, and formally opened by Boris Johnson, Mayor of London on 12 January 2009. Following completion, the project was shortlisted for the 2009 Prime Minister's Better Public Building Award.

The original station was closed in mid-2008 for complete reconstruction. The two terminal tracks either side of a narrow island platform were replaced by a single track between two platforms, one for arriving passengers and the other for departing (Spanish solution). It reopened on 2 March 2009.

As part of an upgrade to allow three-car trains, strengthening work was necessary at the Delta Junction north of. It was decided to include this in a plan for further grade separation to eliminate the conflict between services to Stratford and from Bank. A new timetable was introduced, with improved frequencies at peak hours. The new grade-separated route from Bank to Canary Wharf is used throughout the day, bypassing West India Quay station until mid-evening. Work on this project proceeded concurrently with the three-car upgrade work and the 'flyunder', and the improved timetable came into use on 24 August 2009.

Stratford International to Canning Town Extension (2011)
In addition to the three-car station extensions, part of which was funded from the 2012 Olympics budget, a line was opened from Canning Town to Stratford and Stratford International along the former North London Line of the national rail system, with additional stations. It parallels the London Underground Jubilee Line for much of its length. A substantial multi-level flying junction was built south of Canning Town to enable trains from Bank/Poplar and Stratford International to operate to either of the eastern termini at Beckton and Woolwich Arsenal. There are through trains between all these points, with different patterns at different times of the day. The extension suffered some delay in opening, being completed in August 2011. It provides a direct link between two of the major Olympics locations: the Stadium and Park at Stratford and the ExCeL adjacent to Custom House on the Beckton line.

Overview


The DLR is 25 mi long, with 45 stations. There are six branches: to Lewisham in the south, and Stratford International in the north,  and Woolwich Arsenal in the east, and Central London in the west, splitting to  and. Although the layout allows many different routes, the seven following are operated in normal service:
 * Bank to Lewisham
 * Bank to Woolwich Arsenal
 * Stratford to Canary Wharf
 * Stratford to Lewisham (Monday – Friday morning peak only)
 * Stratford International to Beckton (weekday off peak and weekends)
 * Stratford International to Woolwich Arsenal (weekday peak hours only)
 * Tower Gateway to Beckton

There is capability for an additional shuttle from Canning Town to Prince Regent when exhibitions are in progress at the ExCeL exhibition centre.

At terminal stations trains reverse direction in the platforms except at Bank where there is a reversing headshunt beyond the station. Many peak-hour trains on the Lewisham route from Stratford turn back at Canary Wharf. During service disruption or planned engineering work, trains can also turn back at and. Trains serve every station on the route, but before mid-evening trains from Bank to Lewisham do not call at West India Quay because they are routed along the flyunder track to avoid junction conflicts. During long-term works for extension projects, other routes may be operated at weekends, such as Beckton to Lewisham if the Bank branch is closed.

The northern, southern and south-eastern branches terminate at the National Rail stations at Stratford, Stratford International, Lewisham and Woolwich Arsenal. Other interchanges with National Rail are at Limehouse, Greenwich and West Ham.

Between Limehouse and Tower Gateway, the DLR runs parallel to the LTS Line.

Stations


Most stations are elevated, with others at street level, in cutting or underground. Access to the platforms is mostly by staircase and lift, with escalators at some stations. From the outset the system has been fully accessible to wheelchairs; much attention was paid to quick and effective accessibility for all passengers. The stations have high platforms matching the floor height of the cars, allowing level access for passengers with wheelchairs or pushchairs.

Most stations are of a modular design dating back to the initial system, extended and improved with two side platforms, each with separate access from the street, and platform canopies, although few examples remain of the original, distinctive rounded roof design. Stations are unstaffed, except the underground stations at, , and Woolwich Arsenal for safety reasons, a few of the busier interchange stations, and City Airport, which has a ticket office for passengers unfamiliar with the system. Canning Town, Custom House and Prince Regent are normally staffed on the platform whenever there is a significant exhibition at the ExCeL exhibition centre.

On 3 July 2007, DLR officially launched an art programme called DLR Art, similar to that on the London Underground, Art on the Underground. Alan Williams was appointed to produce the first temporary commission, called "Sidetrack", which portrays the ordinary and extraordinary sights, often unfamiliar to passengers, on the system and was displayed throughout the network.

Fares and ticketing
The system is part of the London fare zone system, and Travelcards that cover the appropriate zones are valid. There are one-day and season DLR-only "Rover" tickets, plus a one-day DLR "Rail and River Rover" ticket for the DLR and City Cruises river boats. Oyster pay-as-you-go is also available; passengers need to touch both in and out on the platform readers or pass through the automatic gates. Tickets can be purchased from ticket machines at the entrance to the platforms, and are required before entering the platform. There are no ticket barriers at DLR-only stations, and correct ticketing is enforced by on-train checks by the PSA. Passengers without a correct ticket and pay-as-you-go Oyster users who have failed to touch in at the start of the journey may be liable to an £80 penalty fare or prosecution for fare evasion. There are barriers at Bank,, Woolwich Arsenal, West Ham and , where the DLR platforms are within a London Underground or National Rail barrier line.

Performance
Within a year of launch, annual passenger numbers were 17 million. This increased to 64 million in 2009 and more than 80 million in 2011. While the first five years were plagued by unreliability and operational problems, the system has now become highly reliable. In 2008, 87% of the population of North Woolwich were in favour of the DLR.

The Parliamentary Transport Select Committee has reviewed light rail. Due to the success of the DLR, proposals for similar systems elsewhere have emerged. The North and West London Light Railway is a plan for an orbital railway serving the other side of London.

The DLR has been successful, as have other recent light rail systems. However, the DLR has been criticised for having been designed with insufficient capacity to meet the demand that quickly arose. The level of demand was underestimated. In 1989 such criticism was aimed at GEC, a major contractor for construction.

Until 1 July 2013, the only bicycles that were allowed were folding ones. DLR stated that this is because if evacuation is required, they would slow down the process. DLR cars, especially older rolling stock, were not designed with bicycles in mind – if they were allowed, they might obstruct doors and emergency exits. One incident in 2007 involved a station manager refusing to allow a train to leave before several triathlon competitors left. On 1 July 2013, DLR embarked on a trial of allowing all cyclists to use the trains outside of weekday commuter peak hours, except at Bank station.

Rolling stock


The DLR is operated by high-floor bi-directional single-articulated Electric Multiple Units (EMUs). Each car has four doors on each side, and two or three cars make up a train. There are no cabs because normal operations are automated, and a small driver's console is concealed behind a locked panel at each end, from which the PSA can drive the car. Consoles at each door opening allow the PSA to control door closure and make announcements whilst patrolling the train. With the absence of a driver's position, the fully glazed car ends provide a forward and rear view for passengers. The top speed is 100 km/h.

Despite having high floors and being automated, the cars are derived from a German light-rail design intended for street running. All cars look similar but there have been several different types, some still in service, others sold to other operators. B2007 units were purchased from Bombardier in 2005 and delivered between 2007 and 2010.

Depots
There are operating and maintenance depots at Poplar, now secondary to the larger site at Beckton, built on the site of the Beckton Gas Works in 1996. Rolling stock is kept at both locations, which have maintenance workshops and extensive open-air carriage sidings. The Poplar depot, which is also the operating headquarters of Docklands Light Railway Ltd and Serco Docklands, houses diesel locomotives used for track maintenance. Poplar depot is alongside the north side of the Stratford line east of the station, and Beckton depot is to the east of the line on a long spur north-east of Gallions Reach.

One of the diesel locos stabled at Poplar is 1979 GEC Traction 0-4-0. One of three built for Shotton Steelworks. Since they were used at the steelworks, one has been scrapped, one has recently been acquired by the Yorkshire Wolds Railway and the third is now at Poplar named "Kevin Keaney".

Signalling technology
Originally the DLR used signalling based on a fixed-block technology developed by GEC-General Signal and General Railway Signal. This was replaced in 1994 with a moving-block TBTC (Transmission Based Train Control) system developed by Alcatel, called SelTrac. The SelTrac system was bought by Thales in 2007 and updates are provided by Thales Rail Signalling Solutions. The same technology is used by rapid transit systems including Vancouver's SkyTrain, Toronto's SRT, San Francisco's Municipal Railway (MUNI) and Hong Kong's MTR. The SelTrac S40 system has also recently been adopted by the London Underground Jubilee line and is being introduced on the Northern line. Transmissions occur via an inductive loop cable between each train's Vehicle On-Board Controller (VOBC) and the control centre (VCC, SMC) at Poplar. If this link is broken and communication is lost between the VOBC and VCC, SMC, the train stops until it is authorised to move again. If the whole system fails the train can run in restricted manual at 12 mph for safety until the system is restored and communication is re-established. Emergency brakes can be applied if the train breaks the speed limit during manual control or overshoots a fixed stopping point, or if it leaves the station when the route has not been set.

SelTrac: Standard Elektrik Lorenz Transport Control System VOBC: Vehicle On-Board Controller SMC: System Management Center VCC: Vehicle Control Center

Current developments
With the development of the eastern Docklands as part of the Thames Gateway initiative and London’s staging of the 2012 Summer Olympics, several extensions and enhancements are under construction, being planned or being discussed.

Upgrading entire system to three-car trains

 * Status – Complete

Capacity has been increased by upgrading for three-car trains. The alternative of more frequent trains was rejected as the signalling changes needed would have cost no less than upgrading to longer trains and with fewer benefits. The railway was built for single-car operation, and the upgrade required both strengthening viaducts to take heavier trains and lengthening many pre-extension platforms which were not originally built to take three-car trains. The extra capacity was useful for the 2012 Summer Olympics, which increased the use of London's transport network. The main contractor for the expansion and alteration works is Taylor Woodrow.

Elverson Road, Pudding Mill Lane (Stratford-bound platform), Royal Albert, Gallions Reach and Cutty Sark have not been extended for three-car trains; such extension may be impossible in some cases. Selective door operation is used, with emergency walkways in case a door fails to remain shut. station is underground, and both costs and the risk to nearby historic buildings prevent platform extension. The tunnel has an emergency walkway. Additional work beyond that needed to take the three-car trains has been carried out at some stations. This included replacing canopies with more substantial ones along the full platform length. A new station has been built 200 m east of the former location as nearby curves precluded lengthening. now has a third platform and all its platforms have full-length canopies. was closed until March 2009 and re-opened as a single-track three-car terminus with two platforms, one for boarding and the other for alighting.

For this upgrade DLR purchased an additional 31 cars compatible with existing rolling stock. The works were originally planned as three phases: Bank-Lewisham, Poplar-Stratford, and the Beckton branch. The original £200m contract was awarded on 3 May 2007. Work started in 2007 and Bank-Lewisham was originally due to be completed in 2009. However, the work programme for the first two phases was merged and the infrastructure work was completed by the end of January 2010. The Lewisham-Bank route now runs three-car trains exclusively. They started running on the Beckton branch on 9 May 2011. Stratford to Lewisham and Bank to Woolwich Arsenal services now operate as three-car trains; other routes will run the longer trains when demand requires it.

Stratford International extension

 * Status – Complete

The extension to Stratford International, taking over the North London Line from Canning Town to Stratford, links the Docklands area with domestic high-speed services on High Speed 1. It was an important part of transport improvements for the 2012 Olympic Games, much of which were held on a site adjoining Stratford International. The first contract for construction work was awarded on 10 January 2007 and construction started in mid-2007. Originally scheduled to open in mid-2010, the line opened on 31 August 2011.

Station names in bold are former North London Line stations.

New stations are:
 * (on the site of Stratford Market)
 * Stratford International
 * (on the site of Stratford Market)
 * Stratford International
 * (on the site of Stratford Market)
 * Stratford International
 * Stratford International

From Canning Town to Stratford the extension runs parallel to the London Underground (Jubilee line). As well as providing interchange with the adjacent Jubilee line stations, there are additional DLR stations at Star Lane, Abbey Road and Stratford High Street.

At Stratford new platforms have been built for the North London Line at the northern end of the station. The old platforms (formerly 1 and 2) adjacent to the Jubilee line have been rebuilt for the DLR, renumbered 16 (towards Stratford International) and 17 (towards Beckton/Woolwich Arsenal). Interchange between the Stratford International branch and DLR trains via Poplar is possible although the platforms are widely separated and at different levels. There is no physical connection between the two branches. As part of the Transport & Works Act (TWA) application, Royal Victoria on the Beckton branch has been be extended to accommodate three-car trains, with a siding to enable trains to reverse there, using land released by the closure of the parallel North London Line. A partly grade-separated junction has been built south of Canning Town to prevent conflicting movements between the Bank branch and the Stratford International branch to and from the Beckton and Woolwich Arsenal branches.

Relocation of Pudding Mill Lane station

 * Status – Under construction

When Crossrail is built, one of its tunnel portals will be on the site of Pudding Mill Lane station. As a consequence, work has begun to divert the DLR between City Mill River and the River Lea on to a new viaduct further south. This will include a replacement station. The current station stands on the only significant section of single track on the system, between Bow Church and Stratford, though the opportunity will be taken to double the track in three stages, to improve capacity. There was originally no provision for works beyond the realigned section in the Crossrail Act.

Dagenham Dock extension



 * Status – Not currently being developed

This proposed extension from to Dagenham Dock via the riverside at Barking would connect the Barking Reach area, a formerly industrial area now due to be a major redevelopment as part of the London Riverside, with Docklands. It would cover major developments at Creekmouth, Barking Riverside, Dagenham Dock Opportunity Area, and five stations are planned, at Beckton Riverside, Creekmouth, Barking Riverside, Goresbrook (formerly Dagenham Vale) and Dagenham Dock. The extension is key if English Partnerships' plan is to work. As shown in DLR's first consultation leaflet, there are proposals to extend further, possibly to or Rainham, or even to the other side of the Thames, including one or two new stations at Thamesmead, and then on to Abbey Wood, for North Kent Line services to Dartford and The Medway Towns, as well as Crossrail connections.

Construction was not expected to start until 2013, and the earliest expected completion date was 2017. However, the financial downturn meant that TfL requested a delay to the public enquiry while funding was clarified. Given that the purpose of the extension was to serve as-yet unbuilt homes, it became very difficult to predict timescales for this project. The project has been reported to have been cancelled by the Mayor of London Boris Johnson as a cost-cutting measure, although there have been calls for this to be reconsidered,  the extension being regarded by Barking and Dagenham council as essential to regenerating the area.

In October 2009, the plan had seemed to be once again under consideration. The Mayor's Transport Strategy stated that the Mayor, through Transport for London, would investigate the feasibility of the extension to Dagenham Dock as part of the housing proposals for Barking Riverside.

Thames Wharf station

 * Status – On hold

Thames Wharf has been the planned name for two separate DLR stations. In 1994 the proposed location was between and. Subsequently the name was transferred to a potential future development on the London City Airport extension between and, due west of the western end of Royal Victoria Dock. Since the station's intended purpose is to serve the surrounding area (currently a mix of brownfield and run-down industrial sites) when it is regenerated, the development is indefinitely on hold due to the area being safeguarded for the Silvertown Link, a new Thames river crossing that has been proposed but currently has no timetable for implementation.

Connaught Road/Silvertown Interchange station

 * Status – Proposed

A site near to London City Airport has been identified as a possible additional station on the London City Airport branch. The Connaught Tunnel is here, and will be used again when some of the former Custom House to North Woolwich section of the Eastern Counties and Thames Junction Railway is taken over by Crossrail. However, no plans have emerged as to if or when a station might be built here, even though the original extension was designed to allow this. It may be located south of the Connaught Crossing.

Victoria/Charing Cross extensions

 * Status – Proposed – 2006

In February 2006 a proposal to extend the DLR to station from  DLR branch was revealed. The idea, originating from a DLR "Horizon Study", is at a very early stage at the moment, but would involve extending the line from Bank in bored tunnels under Central London to the Charing Cross Jubilee Line platforms, which would be brought back to public use. These platforms are now on a spur off the current Jubilee line and are not used by passenger trains. It has since been revealed that a proposed route as far as station will be investigated.

While not confirmed, it is probable that the Charing Cross scheme would use the overrun tunnels between Charing Cross Jubilee platforms and slightly west of. These tunnels were intended to be incorporated into the abandoned Phase 2 of the Fleet Line (Phase 1 became the original Jubilee Line, prior to the Jubilee Line Extension). However they would need enlargement because DLR gauge is larger than tube gauge and current safety regulations would require an emergency walkway in the tunnel.

Two reasons driving the proposal are capacity problems at Bank, having just one interchange between the DLR and the central portion of Underground, and the difficult journeys faced by passengers from Kent and South Coast between their rail termini and the DLR. Intermediate stations would be at City Thameslink/Ludgate Circus and Aldwych, which was intended for future connection with the proposed but now abandoned Cross River Tram.

Euston/St Pancras extension

 * Status – Proposed

Recent strategy documents have proposed a DLR extension to Euston and St Pancras. Transport for London have considered driving a line from City Thameslink via north to the rail termini. The main benefit of such an extension would be to broaden the available direct transport links to the Canary Wharf site. It would create a new artery in central London and help relieve the Northern and Circle lines and provide another metro line to serve the High Speed line into Euston.

Lewisham to Catford/Lewisham to Beckenham Junction extension

 * Status – Proposed – 2006

This possible extension was considered during the latest Horizon Study. The route would follow the Southeastern line and terminate between Catford and Catford Bridge stations. It has been seen as attractive to the district, as has the current terminus at Lewisham, built in an earlier extension. A map published in 2010 by Transport for London suggests that a further extension from Catford to Forest Hill has also been considered.

However, early plans showed problems due to station being only marginally lower than the busy A20 road, which impedes any extension. The plan is however being revised. When the Lewisham extension was first completed there were proposals to continue further to Beckenham to link it up with the Tramlink system. However, the way in which Lewisham station was built impedes this possible extension and it would prove costly to redevelop.

Lewisham to Bromley North extension

 * Status – Proposed – 2012

Another proposal is to Bromley North by taking over the Bromley North Line, a short National Rail branch line which has no direct services to London. The scheme being considered by Transport for London and the London Borough of Bromley would convert the branch line to DLR operation. Although Lewisham Council planned to re-route the A20 road and redevelop the area south of Lewisham DLR station, the plans published in 2012 have no safeguarded route for an extension, making one unlikely.

Overrun of station buffers
On 10 March 1987, before the system opened, a test train crashed through buffer stops at the original high-level terminus and was left hanging from the end of the elevated track. The accident was caused by unauthorised tests being run before accident-preventing modifications had been installed. The train was being driven manually at the time.

Collision at West India Quay bridge
On 22 April 1991, two trains collided at a junction on the bridge during morning rush hour, requiring a shutdown of the system and evacuation of passengers by ladder. One train was travelling automatically, while the other was under manual control.

South Quay bombing
On 9 February 1996, the Provisional Irish Republican Army blew up a lorry under a bridge near, killing two people and injuring many others. The blast caused £85 million of damage and marked an end to the IRA ceasefire. Significant disruption was caused and a train was stranded at Island Gardens, unable to move until the track was rebuilt.

Management
Prior to 1997 the DLR was a wholly owned subsidiary of London Regional Transport. In 1992 it was transferred to the London Docklands Development Corporation, sponsored by the Department of Environment.

The infrastructure is owned by Docklands Light Railway Ltd, part of the London Rail division of Transport for London, which also manages London Overground, London Tramlink and Crossrail. The first concession was awarded to Serco Docklands Limited for seven years; operations began in April 1997. A management buyout backed by Serco management later sold its shares to Serco. A two-year extension was granted in 2002.

In February 2005 Transport for London announced Balfour Beatty/Keolis, First Carillion, RATP/Transdev and Serco had been shortlisted to operate the concession.

In November 2005 Transport for London announced Serco had retained the concession for seven years from May 2006.

The Lewisham, City Airport and Woolwich Arsenal extensions were designed, financed, built and maintained by private companies: City Greenwich Lewisham (CGL) Rail, City Airport Rail Enterprises (CARE), and Woolwich Arsenal Rail Enterprises (WARE). However, in 2011, Transport Trading Limited (a subsidiary of Transport for London) purchased the companies responsible for the City Airport and Woolwich Arsenal extensions leaving only the Lewisham extension under private ownership.

In January 2013 Serco's contract was extended until September 2014. In July 2012 Transport for London called for expressions of interest in bidding for the next DLR concession,

In April 2013 Transport for London announced Go-Ahead/Colas Rail, Keolis/Amey Rail, Serco and Stagecoach had been shortlisted to bid for the concession commencing on 14 September 2014. However, on 30 August, just over a week before the bid submission date of 9 September 2013, Go-Ahead/Colas Rail pulled out of the running.