Halcrow has designed a £180 million extension to the Docklands Light railway (DLR) in London that will provide a much-needed transport link between Woolwich town centre, central London and London City airport, and will play an important part in the regeneration of Woolwich and the Royal Docks.
The new line will also provide a transport link to the Olympic village as part of the London 2012 Olympic and Paralympic Games.
The 2.5km extension runs under the River Thames from the existing George V DLR station to a new station at Woolwich Arsenal that integrates light and heavy rail, local bus services, taxis and water boats, to provide the area with a major multimodal interchange.
As lead designer Halcrow was responsible for all aspects of design including tunnelling, piling and diaphragm walls, geotechnics, mechanical and electrical works, building services and structural design, track work, signalling and train control systems, telecommunications and SCADA, rail systems and station architecture (in association with project architect). Our pedestrian modelling team modelled passenger flows in an around the station, and our traffic management and highways teams managed all associated highways works.
We utilised live 4D CAD modelling software for clash detection and to optimise systems integration.
The design was successfully delivered to a challenging programme, and Halcrow subsequently provided construction supervision and support during the testing, commissioning and handover of the completed system
The new station, the largest on the DLR network, is fully integrated with the existing National Rail station, which was upgraded as part of this project. It is built over three storeys and incorporates step-free access to the ticket hall, platforms and trains, and a step free interchange with the National Rail services.
The underground station was designed for a top-down construction method, which minimised the impact on the surrounding road network and protected adjacent buildings. Effective construction planning allowed the construction to be carried out below and alongside the existing live railway with the minimum of disruption to services.
In addition to the station, the project included twin 1.8km long, 6m diameter, bored running tunnels under the River Thames. They were bored using an earth pressure balancing tunnel boring machine and lined with a steel fibre-reinforced trapezoidal segmental lining. During the tunnel excavation 100,000 cubic metres of spoil was taken out and removed by barge to minimise the environmental impact and avoid adding congestion to London’s roads.
The project also included a major intervention shaft and headhouse, which accommodates power distribution and communications systems. It is 15m in diameter and 40m deep and is positioned immediately adjacent to the river flood wall.
The extension was built for Woolwich Arsenal Rail Enterprises, a joint venture of Land Securities Trillium and the Royal Bank of Scotland, which has a PFI concession agreement to design, build, finance and maintain the new section of track.