North Downs Tunnel

North Downs Tunnel
North portal, with Class 373 on Eurostar service heading to Paris
North portal, dust whipped up by a test train before opening in 2003
South portal, leading under the North Downs at Blue Bell Hill

The North Downs Tunnel is a railway tunnel that carries High Speed 1 through the North Downs, at Blue Bell Hill near Maidstone in Kent, south-east England.

The tunnel was constructed by mechanical excavation of the weak chalk, followed by application of a sprayed concrete lining (SCL), prior to construction of an in-situ reinforced concrete secondary lining. Due to the environmental sensitivity of the area, no pressure relief shafts were provided.

It was completed in December 2001 as part of the first phase of the CTRL, £5 million under budget and five months ahead of schedule. Over 100 workers working in shifts 24 hours a day made this possible, despite the site being perceived as a major risk before the project.

The tunnel is 3.2 kilometres (2 mi) long, with an internal diameter of 12 metres (40 ft) and a cross-sectional area (CSA) of 150 square metres, and descends to a depth of 100 m below the chalk hills. This made it one of the largest (in terms of CSA) and deepest twin-track railway tunnels ever constructed in the UK.

Trains using High Speed 1 can reach speeds of 300 kilometres per hour (186 mph) but, for safety reasons,[citation needed] they will travel at a lower speed through the tunnel and across the Medway Viaduct over the River Medway.

References

Coordinates: 51°19′44″N 0°30′21″E / 51.32890°N 0.50589°E / 51.32890; 0.50589



Wikimedia Foundation. 2010.

Игры ⚽ Поможем написать реферат

Look at other dictionaries:

  • North Downs Line — Overview Type Suburban rail, Heavy rail System National Rail …   Wikipedia

  • North Kent Line — The North Kent Line, shown with other railway lines in Kent. Overview Type Commuter rail, Suburban rail System …   Wikipedia

  • Channel Tunnel Rail Link — High Speed One (HS1, früher CTRL) Legende …   Deutsch Wikipedia

  • North London Line — A Class 378 Capitalstar at Canonbury in June 2010 Overview Type Commuter rail, Suburban rail, Freight …   Wikipedia

  • Channel Tunnel Rail Link — High Speed 1 High Speed 1 (Channel Tunnel Rail Link) Ligne de Londres à Folkestone (tunnel sous la Manche) Carte de la ligne …   Wikipédia en Français

  • Tunnel-Creek-Nationalpark — Höhleneingang …   Deutsch Wikipedia

  • North-West T-way — Mode Bus rapid transit line Owner Transport for NSW Operator(s) Busways Hillsbus …   Wikipedia

  • Folkestone Downs — Infobox SSSI name=Folkestone To Etchinghill escarpment aos=Kent interest=Biological and Geological gridref=TR171394 to TR235376 area=269.5 hectares notifydate=1951 http://www.natureonthemap.org.uk/map.aspx Natural England ] The Folkestone Downs… …   Wikipedia

  • Scarborough North Bay Railway — North Bay Railway[1] Legend …   Wikipedia

  • Thomas M. Downs — (* 1944 in Kansas City (Missouri)) ist ein amerikanischer Manager und Staatsbediensteter. Er war unter anderem Chairman und CEO der staatlichen Bahngesellschaft Amtrak. Leben Thomas M. Downs studierte an der Rockhurst University, der University… …   Deutsch Wikipedia

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”