Docklands Light Railway



The Docklands Light Railway (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 below-ground stations are staffed to comply with underground station fire and safety requirements. Similar proposals have been made for the Tube.

The DLR is operated under a franchise awarded by Transport for London to KeolisAmey Docklands, a joint venture between transport operator Keolis and infrastructure specialists Amey plc. It was previously run for over 17 years by 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 Fiscal Year 2014, the DLR carried 110.2 million passengers. It has been extended several times and further extensions are under consideration.

Origins and development
The docks immediately east of Central London began to decline in the early 1960s as cargo became containerised. They had been connected to the national railway network via the London and Blackwall Railway (L&BR), which was closed in 1966 for lack of traffic. The opening of the Tilbury container docks, further east in Essex, finally rendered them redundant, and in 1980 the government gained control of the now-derelict area.

As early as 1972, consideration was given to how to redevelop the moribund Docklands. Travis Morgan & Partners were commissioned by the London Docklands Study Team to consider the issue. They proposed, among other recommendations, that a "minitram" people-mover system capable of carrying up to 20 people in each unit should be constructed to connect the Docklands with the planned Fleet line tube railway terminus at Fenchurch Street railway station. The Greater London Council formed a Docklands Joint Committee with the Boroughs of Greenwich, Lewisham, Newham, Southwark and Tower Hamlets in 1974 to undertake the redevelopment of the area. A light railway system was envisaged, terminating either at Tower Hill tube station or at Fenchurch Street, but both options were seen as too expensive. Nonetheless, in 1976 another report proposed a conventional tube railway for the area and London Transport obtained Parliamentary powers to build a line from Charing Cross railway station to Fenchurch Street, Surrey Docks (now Surrey Quays railway station), the Isle of Dogs, North Greenwich and Custom House to Woolwich Arsenal. This was intended to be the second stage of the Fleet line – which had been renamed the Jubilee line, the first stage of which opened in 1979 from to. However, when the Conservative Party came to power in May 1979 under Margaret Thatcher, the plans to extend the Jubilee line were halted and the new government insisted that a lower-cost option should be pursued.

The government created the London Docklands Development Corporation (LDDC) in July 1981 to coordinate the redevelopment of the Docklands. The need to provide a cheap public transport solution led to it commissioning London Transport to evaluate a number of exclusively light rail options. The core of the route ran alongside the Great Eastern line out of London and south along the former London & Blackwall Railway line through the Isle of Dogs. Three terminus options were proposed at the west end, at Tower Hill, Minories and Aldgate East. The Tower Hill option would have required a low-level interchange to be constructed alongside the existing Underground station, but this would have been a very costly venture. The Minories option, a high-level station virtually on the site of the old Minories railway station, was selected and became the current Tower Gateway DLR terminus. Aldgate East would have been perhaps the most ambitious of all of the options, as it originally envisaged a low-level connection with the District line that would have allowed DLR trains to run on Underground tracks to a variety of central London destinations. However, it quickly became apparent that there was no capacity on the existing network for integrating the DLR into the Underground.

Two southern terminus options were put forward, at Cubitt Town (today's Island Gardens station) and Tiller Road, on the west side of Millwall Dock, with two possible routes to reach them. A "western" route would have run from the Westferry station alongside West Ferry Road via Cuba Street, then either terminating at Tiller Road or continuing over Millwall Docks Cut to a terminus at Cubitt Town. The "central" option required the West India Docks to be infilled or bridged and would run down the middle of the peninsula, through what was at the time an area of derelict warehouses. Ultimately this latter option was chosen, though the 1981 London Transport report warned that without extensive development around Canary Wharf the area would be "very isolated with poor traffic prospects" – as indeed it was, for a number of years.

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 formally 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. It was mainly elevated on disused railway viaducts or new concrete viaducts, and adopted disused surface railway formations between Poplar and Stratford. The trains were fully automated, controlled by computer, and had no driver; a Passenger Service Agent (PSA) on each train, originally referred to as a "Train Captain", was responsible for patrolling the train, checking tickets, making announcements and controlling the doors. PSAs could take control of the train in circumstances including equipment failure and emergencies. A total of eleven EMUs supplied by Linke-Hofmann-Busche comprised the first generation of the Docklands Light Railway rolling stock.

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, although later extension included stations below ground which were required by law to be staffed in case of evacuation.

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, as it did not connect directly with the nearby Tower Hill tube station or Fenchurch Street railway station. The criticism arose partly because the system usage was higher than expected. 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, which opened in 1991. This extension left on a stub. The original trains were not suitable for use underground due to a lack of fire-proofing. They were operated for a time on the above-ground sections only, and were later sold.

As the Canary Wharf office complex grew, Canary Wharf DLR 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 east of Docklands needed better transport connections to encourage development, and a fourth branch, towards Beckton, was planned, with several route options available. A route from via  and the north side of the Royal Docks complex was chosen, and opened in 1994. Initially it was thought the line was likely to be underutilised, due to the sparse development in the area. As part of this extension, one side of the original flat triangular junction was replaced by a grade-separated junction west of Poplar. Poplar was rebuilt to give cross-platform interchange between the Stratford and Beckton lines, with a new grade-separated junction built east of the station at the divergence of 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 via Greenwich and Deptford, terminating at Lewisham railway station. The ambitions of the operators were supported by politicians in Parliament, including the future Labour Deputy Prime Minister John Prescott, and Lord Whitty; and by 1996 construction work had begun.

The Lewisham extension opened on 3 December 1999. It left the Island Gardens route south of the Crossharbour turn-back sidings, and dropped gently to, where a street-level station replaced the high-level one on the former London & Blackwall Railway viaduct. The line then entered a tunnel, following the route of the viaduct to a shallow subsurface station at, accessible by stairs or a lift. It crossed under the Thames to in the centre of Greenwich, and surfaced at Greenwich railway 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 railway station, 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 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 train station 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.

Current system
The DLR is 24 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 (extended to Lewisham in the Monday to Friday morning peak)
 * Stratford International to Beckton
 * Stratford International to Woolwich Arsenal
 * 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 trains from Bank to Lewisham do not call at West India Quay because they are routed along the diveunder 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, while out of station interchanges for Oyster card holders exist between Shadwell DLR station and London Overground's station of the same name, and between Fenchurch Street and the DLR's western termini Tower Gateway and Bank.

Between Limehouse and Tower Gateway, the DLR runs parallel to the London, Tilbury and Southend Railway.



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; or NFC enabled bank card holders (contactless) 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 random on-train inspections by the PSA. Passengers without a correct ticket, pay-as-you-go Oyster users or a contactless bank card who have failed to touch in at the start of the journey may be liable to a £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, to more than 80 million in 2011, and most recently to 110.2 million annual passengers in Fiscal Year 2014. 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. As of January 2014, the trial was made permanent, and full-size bicycles are now carried on DLR at off-peak hours and weekends (except Bank Station)

Rolling stock


The DLR is operated by 145 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 and accessed via a spur at Gallions Reach. 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, KeolisAmey Docklands Ltd and the Emirates Air-Line cable car, 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. Beckton Depot has the only level crossing on DLR. It is an AHB type and the barriers are down unless a user wants to cross, much like Appleford but AHB styled.

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". Its original nickname was "Sooty" because of the amount of exhaust this old engine produced.

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 been adopted by the London Underground Jubilee line and 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 Beckton. 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.

Recent 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 have recently been undertaken.

Upgrading entire system to three-car trains
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 was Taylor Woodrow.

Elverson Road, 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. 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 was also carried out at some stations. This included replacing canopies with more substantial ones along the full platform length. A new has been built 200 m east of the former location as nearby curves precluded lengthening. now has a third platform. 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 sometimes operate as three-car trains; other routes will run the longer trains when demand requires it.

Stratford International extension
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. On 11 November 2015 the Mayor of London announced that all stations on this line will be rezoned from zone 3 to zone 2/3.

Station names in bold are former North London Line stations.

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

From Canning Town to Stratford the extension runs parallel to the Jubilee line of the London Underground. 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
One of the tunnel portals for Crossrail is on the original site of Pudding Mill Lane station. As a consequence, work was carried out to divert the DLR between City Mill River and the River Lea on to a new viaduct further south. This included a replacement station, which opened on 28 April 2014. The former station stood 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 Tunnel, 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 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 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

In 2011, strategy documents 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 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.

Gallions Reach Crossing

 * Status – Proposed

The proposed Gallions Reach Crossing has been suggested by TfL as allowing a branch to leave the existing DLR network at Gallions Reach, and cross the river on the proposed tunnel/bridge and into Thamesmead. The new branch could then pass through Thamesmead and towards Abbey Wood, Woolwich, or northwards towards Barking. On 4 October 2016 the London Assembly approved the extension to Thamesmead.

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
DLR was a wholly owned subsidiary of London Regional Transport until 1992 when it was transferred to the London Docklands Development Corporation.

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, Emirates Air-Line Cable Car and Crossrail. The first franchise 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 that Balfour Beatty/Keolis, First Carillion, RATP/Transdev and Serco had been shortlisted to operate the franchise.

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

The Lewisham, City Airport and Woolwich Arsenal extensions were designed, financed, built and maintained by private companies (concessionnaires): City Greenwich Lewisham (CGL) Rail, City Airport Rail Enterprises (CARE), and Woolwich Arsenal Rail Enterprises (WARE). In 2011, Transport Trading Limited (a subsidiary of Transport for London) bought out 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 franchise,

In April 2013 Transport for London announced that Go-Ahead/Colas Rail, Keolis/Amey, Serco and Stagecoach had been shortlisted to bid for the next franchise. 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. The franchise was awarded to Keolis/Amey with a handover date of 7 December 2014.

In media
The DLR appears in the video to Sean Paul and Clean Bandit's single "Rockabye".

Woolwich Arsenal plays an underground station in Athens in Jason Bourne.