Page 8

evolutionsummer2013

INfrasTrucTure The decade was marked by several The challenge for LU and the incidents across the network culminating in construction industry the King’s Cross fire disaster (November Use of the underground is now at its 1987). This event proved to be a watershed highest ever levels – 1.2 billion passenger in reversing the lack of investment and journeys last year. The key objectives for LU questioning the management of safety on today are to sustain and further enhance the underground. LU reorganised to be reliability of services, to maximise the a more customer-focused organisation, capacity of the current network, to enable reviewed standards and procedures growth of the network and to deliver and introduced a safety improvement continuous improvement of customer programme to remove non-compliant service in response to customers’ changing materials and to improve fire detection and needs and behaviours. suppression. The LU infrastructure with its underlying 1990s construction history and the constraints of Figure 6: Victoria line construction from operating a high capacity electrified railwayDuring the 1990s the underground Ferry Lane to Walthamstow station showing 20 hours a day presents many challenges.began to regain strength, with growth of passenger numbers and redevelopment in the segment erection associated with a Tunnel Boring Machine With such history comes the responsibilityLondon docklands. This resulted in further consideration of the extension to the to maintain heritage for future generations. Jubilee line and at last construction started There are many listed buildings and The Victoria line construction incorporated at the end of 1993. features across the network that should be a significant amount of standard designs preserved and maintained. This frequently that have generally performed well over the presents problems when it comes to last forty or more years. The architectural integrating the 21st century with the 19th treatment was simple and uninspiring with or 20th century. Obtaining materials and common design features across the line components to match the old buildings reflecting the limited budget available. At is a constant problem. There are also this time a set of ‘new works’ standards problems when trying to justify existing were established for projects to follow. construction that is non-compliant with current standards, ie helical staircases The 1970s were difficult years for London’s and materials that are non-compliant, and transport greatly influenced by politics platforms that slope towards the track. and funding difficulties however London Material compliance at subsurface stations is Transport secured funding for construction essential for safety plus the need to ensure of another new line across London – the Figure 7: The grand entrance into adequate evacuation and fire detection. Fleet line (now called the Jubilee line). Canary Wharf station built as part of the Encouraged by the GLC this was identified Jubilee Line Extension Ongoing maintenance is a major issue as a priority to ease congestion on the with the limited time for access and the Bakerloo line and to improve links with The Jubilee line extension resulted in presence of live electricity conductor rails. London docklands. The first stage was construction of a modern metro line for Generally maintenance works on and built between Baker Street and Charing London with large new stations with access around the tracks are only permitted in the Cross (opened 1979) projected to pass for all and enhanced safety features. Each four hour window each night, and works through the City of London and onto new station was constructed with lifts and at busy stations are only practical outside docklands. This line was an extension of the escalators plus escape stairs and ventilation of peak periods. Also, the size of the tube technology applied on the Victoria line but to enable safe evacuation. Also, for the tunnels restricts the rail mounted plant without automatic trains. Also, at this time first time in London, platform edge doors that can be used to service the railway. authorisation was achieved for an extension were installed at subsurface stations. The Efficient renewal of the tracks within the of the Piccadilly line into Heathrow Airport tunnelling works included use of sprayed tube tunnels has been a constant challenge with a later loop line to Terminal 4. concrete tunnel linings on some of the within the available time each night. large tunnels at stations and long lengths 1980s of bored tunnels in the poor ground There are many cases of water ingress The 1980s saw further reduction in conditions south of the river Thames using around the subsurface infrastructure network use with ongoing influence several tunnel boring machines. Spectacular that need to be managed and controlled. from politicians. There were no new station designs were commissioned from Uncontrolled water can affect critical underground lines built with the Jubilee leading architects and this led to much equipment that can have a serious impact line extension being put on hold while a use of glazing including structural glass on services. Cleaning of the network is cheaper alternative, the Docklands Light and a variety of finishes. There is much a huge task both at stations and in the Railway, was constructed. Considerable dependence on the exposed finishes of the running tunnels. efforts were made to reduce costs including as-constructed structures. a move to one person train operation. 6


evolutionsummer2013
To see the actual publication please follow the link above