London Underground - London Underground New Trains for Deep-Level Lines - HLondon Underground - H London Underground New Trains for Deep-Level Lines In mid-2014 Transport for London issued a tender for up to 18 trains for the Jubilee line and up to 50 trains for the Northern line. These would be used to increase frequencies and cover the Battersea extension on the Northern line. In early 2014 the Bakerloo, Central, Piccadilly and Waterloo & City line rolling-stock replacement project was renamed New Tube for London (NTfL) and moved from the feasibility stage to the design and specification stage. The study had showed that, with new generation trains and re-signalling:
The project is estimated to cost £16.42 billion (£9.86 billion at 2013 prices). A notice was published on 28 February 2014 in the Official Journal of the European Union asking for expressions of interest in building the trains. On 9 October 2014 TFL published a shortlist of those (Alstom, Siemens, Hitachi, CAF and Bombardier) who had expressed an interest in supplying 250 trains for between £1.0 billion and £2.5 billion, and on the same day opened an exhibition with a design by PriestmanGoode. The fully automated trains may be able to run without drivers, but the ASLEF and RMT trade unions that represent the drivers strongly oppose this, saying it would affect safety. The invitation to tender for the trains was issued in January 2016, the specifications for the Piccadilly line infrastructure are expected in 2016, and the first train is due to run on the Piccadilly line in 2023. Siemens Mobility's Inspiro design was selected in June 2018 in a £1.5 billion contract. London Underground Ventilation and Cooling When the Bakerloo line opened in 1906, it was advertised with a maximum temperature of 60 °F (16 °C), but over time the tube tunnels have warmed up. In 1938 approval was given for a ventilation improvement programme, and a refrigeration unit was installed in a lift shaft at Tottenham Court Road. Temperatures of 117 °F (47 °C) were reported in the 2006 European heat wave. It was claimed in 2002 that, if animals were being transported, temperatures on the Tube would break European Commission animal welfare laws. A 2000 study reported that air quality was seventy-three times worse than at street level, with a passenger inhaling the same mass of particulates during a twenty-minute journey on the Northern line as when smoking a cigarette. The main purpose of the London Underground's ventilation fans is to extract hot air from the tunnels, and fans across the network are being refurbished, although complaints of noise from local residents preclude their use at full power at night. In June 2006 a groundwater cooling system was installed at Victoria station. In 2012, air-cooling units were installed on platforms at Green Park station using cool deep groundwater and at Oxford Circus using chiller units at the top of an adjacent building. New air-conditioned trains have been introduced on the sub-surface lines, but was initially ruled out for the tube trains due to space being considered limited on tube trains for air-conditioning units and that these would heat the tunnels even more. The New Tube for London, which will replace the trains for the Bakerloo, Central, Waterloo and City and Piccadilly lines, is planned to have air conditioning for the new trains along with better energy conservation and regenerative braking. In the original Tube design, trains passing through close fitting tunnels act as pistons to create air pressure gradients between stations. This pressure difference drives ventilation between platforms and the surface exits through the passenger foot network. This system depends on adequate cross-sectional area of the airspace above the passengers' heads in the foot tunnels and escalators, where laminar airflow is proportional to the fourth power of the radius, the Hagen–Poiseuille equation. It also depends on an absence of turbulence in the tunnel headspace. In many stations the ventilation system is now ineffective because of alterations that reduce tunnel diameters and increase turbulence. An example is Green Park tube station, where false ceiling panels attached to metal frames have been installed that reduce the above-head airspace diameter by more than half in many parts. This has the effect of reducing laminar airflow by 94%. Originally, air turbulence was kept to a minimum by keeping all signage flat to the tunnel walls. Now, the ventilation space above head height is crowded with ducting, conduits, cameras, speakers and equipment acting as a baffle plates with predictable reductions in flow. Often, electronic signs have their flat surface at right angles to the main air flow, causing choked flow. Temporary sign boards that stand at the top of escalators also maximise turbulence. The alterations to the ventilation system are important, not only to heat exchange, but also the quality of the air at platform level, particularly given its asbestos content. London Underground Lifts and Escalators Originally access to the deep-tube platforms was by a lift. Each lift was staffed, and at some quiet stations in the 1920s the ticket office was moved into the lift, or it was arranged that the lift could be controlled from the ticket office. The first escalator on the London Underground was installed in 1911 between the District and Piccadilly platforms at Earl's Court and from the following year new deep-level stations were provided with escalators instead of lifts. The escalators had a diagonal shunt at the top landing. In 1921 a recorded voice instructed passengers to stand on the right and signs followed in the Second World War. Travellers were asked to stand on the right so that anyone wishing to overtake them would have a clear passage on the left side of the escalator. The first 'comb' type escalator was installed in 1924 at Clapham Common. In the 1920s and 1930s many lifts were replaced by escalators. After the fatal 1987 King's Cross fire, all wooden escalators were replaced with metal ones and the mechanisms are regularly degreased to lower the potential for fires. The only wooden escalator not to be replaced was at Greenford station, which remained until March 2014 when TfL replaced it with the first incline lift on the UK transport network in October 2015. There are 426 escalators on the London Underground system and the longest, at 60 metres (200 ft), is at Angel. The shortest, at Stratford, gives a vertical rise of 4.1 metres (13 ft). There are 184 lifts, and numbers have increased in recent years because of investment in making tube stations accessible. Over 28 stations will have lifts installed over the next 10 years, bringing the total of step-free stations to over 100. Lift and escalators are abundant with advertising posters which can be used for artistic purposes due to the nature of their layout. London Underground Wi-Fi and Mobile Phone Reception In mid-2012, London Underground, in partnership with Virgin Media, trialled Wi-Fi hotspots in many stations, but not in the tunnels, that allowed passengers free internet access. The free trial proved successful and was extended to the end of 2012, whereupon it switched to a service freely available to subscribers to Virgin Media and others, or as a paid-for service. It was not previously possible to use mobile phones on most parts of the Underground (excluding services running overground or occasionally sub-surface, depending on the phone and carrier) using native 2G, 3G or 4G networks, and a project to extend coverage before the 2012 Olympics was abandoned because of commercial and technical difficulties. In March 2020, 2G, 3G and 4G signal was made available on parts of the Jubilee line, between Westminster and Canning Town, throughout the stations and tunnels as part of an initial trial. In June 2021, Vodafone dropped London Underground Wi-Fi connectivity across the entire network. This was restored in April 2023 after control of the Wi-Fi connectivity moved from Virgin Media to Boldyn Networks as part of their 20-year concession deal with Transport for London, providing data connectivity across the entire network. In December 2022, additional mobile coverage, including 5G connectivity, launched at a small subset of stations and tunnel segments on the Central line, with a view to expand to the full set of sub-surface stations and tunnels on the London Underground and Elizabeth Line by the end of 2024. Further stations on the Northern line were launched from January 2023, with additional Northern line stations also being added in June 2023. Not all stations have identical coverage solutions, with some not having 5G connectivity present. As of June 2023, testing has begun on sections of the Bakerloo, Piccadilly and Victoria lines. Mobile Coverage Availability on London Underground Sections of track Available from
July 2023 (tunnel sections)
London Underground Overview London Underground Locale: Greater London, Buckinghamshire, Essex, Hertfordshire London Underground Transit Type: Rapid transit London Underground Number of Lines: 11 London Underground Number of Stations: 272 served (262 owned) London Underground Daily Ridership: 3.15 million (January 2023) London Underground Annual Ridership: 1.026 billion (2022/2023) London Underground Began Operation: 10 January 1863, 160 years ago London Underground Operator(s): London Underground Limited London Underground Reporting Marks: LT (National Rail) London Underground System Length: 402 km (250 mi) London Underground Track Gauge: 1,435 mm (4 ft 8+1⁄2 in) standard gauge (1863–pres.) 7 ft (2,134 mm) Brunel gauge (1863–1869) London Underground Electrification: 630 V DC fourth rail London Underground Average Speed: 33 km/h (21 mph) | |||||
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