Heathrow Airside Road Tunnel
Encyclopedia
Tunnel
A tunnel is an underground passageway, completely enclosed except for openings for egress, commonly at each end.A tunnel may be for foot or vehicular road traffic, for rail traffic, or for a canal. Some tunnels are aqueducts to supply water for consumption or for hydroelectric stations or are sewers...
at London Heathrow Airport
London Heathrow Airport
London Heathrow Airport or Heathrow , in the London Borough of Hillingdon, is the busiest airport in the United Kingdom and the third busiest airport in the world in terms of total passenger traffic, handling more international passengers than any other airport around the globe...
. It connects the airside roads around Terminals 1, 2 and 3 to the airside roads around Terminal 5.
The ART is 1.42 km long, consisting of 60 m of twin-cell cut and cover box at each end, linked by a pair of 1.3 km bored tunnels. The ART was designed and built between 1999 and 2004 by a team of engineers from BAA
BAA plc
BAA Ltd. is the Spanish-owned operator of six British airports and Naples Airport in Italy, making the company one of the largest transport companies in the world. BAA stems from British Airports Authority and is owned by a consortium led by Grupo Ferrovial, a Spanish firm specialising in...
(who own the tunnel), AMEC
AMEC
AMEC plc is a global consultancy, engineering and project management company headquartered in London, United Kingdom. It is focused on the oil and gas, minerals and metals, renewable energy, environment and infrastructure sectors and has offices in 40 countries worldwide...
, Laing O'Rourke, Morgan-Vinci
VINCI
Vinci is a French concessions and construction company, formerly called Société Générale d'Enterprises. It employs over 179,000 people and is the largest construction company in the world by revenue. Vinci is listed at Euronext's Paris stock exchange and is a member of the CAC 40 index...
JV and Mott MacDonald
Mott MacDonald
The Mott MacDonald Group is an employee-owned company management, engineering and development consultancy serving the public and private sectors world-wide...
.
The bored tunnels have internal diameter 8.1 m and were driven by a 9.16 m diameter Herrenknecht
Herrenknecht
Herrenknecht AG is a German manufacturer of tunnel boring machines of all sizes. Herrenknecht is headquartered in Allmannsweier near Schwanau and is the world market leader for heavy tunnel boring machines...
earth pressure balance
Earth pressure balance
Earth pressure balance, or EPB, is a mechanised tunneling method in which spoil is admitted into the tunnel boring machine via a screw conveyor arrangement which allows the pressure at the face of the TBM to remain balanced without the use of slurry.This has allowed soft, wet, or unstable ground...
TBM
Tunnel boring machine
A tunnel boring machine also known as a "mole", is a machine used to excavate tunnels with a circular cross section through a variety of soil and rock strata. They can bore through anything from hard rock to sand. Tunnel diameters can range from a metre to almost 16 metres to date...
. The excavations were lined with a bolted concrete lining 0.45 m thick: these are unusually strong tunnel segments, required because the ART is so close to the surface and, at one point, passes 3 m over the top of the Heathrow Connect
Heathrow Connect
Heathrow Connect is a train operating company in London provided jointly by Heathrow Express and First Great Western, connecting Heathrow Airport with station. The service follows the same route as the Heathrow Express service but serves intermediate stations en route, thus connecting several...
tunnel to Terminal 4.
Each bore contains an unusual road layout, consisting of a single carriageway 6 m wide; just wide enough to allow an airport bus (Cobus
Contrac Cobus
Contrac Cobus is a German bus manufacturer and produces infield shuttle buses used at airports around the globe. The company was founded in 1978 in Wiesbaden, Germany.-Products:* Cobus 2400 - small size bus* Cobus 2700s...
2700) to drive past another bus stopped at the side of the road. The two tunnels are linked by escape cross-passages at intervals of 100–130 m.
The tunnel was opened to airside traffic in March 2005 and is used only by vehicles with security clearance to drive airside. Now that Terminal 5 is fully operational, the ART forms the link between it and the other terminals at Heathrow.
Sources
- Challenging ART for Heathrow, World Tunnelling August 2003, pp 225-229
- Darby, A., The Airside Road Tunnel, Heathrow Airport, England, Proceedings of the Rapid Excavation & Tunneling Conference, New Orleans, June 2003, pp 638-647
- Morgan Est project page on T5