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Other Heathrow third runway

Despite construction of Terminal 5, further long-term growth at Heathrow would require extra runway capacity.

Controversial expansion

The third runway at Heathrow is highly controversial. DfT studies suggest a third "short" runway (2000m as opposed to 4000m) could be constructed to the north of Heathrow, with additional terminal capacity provided by a sixth terminal.

The third runway would be constructed adjacent to the M4 motorway and would involve significant property demolition (260 buildings) and Green Belt use (230ha).

The villages of Sipson and Harmondsworth would essentially be demolished to make way for the new runway and terminal buildings.

A map of the runway location is available from Hillingdon council.

Since the third runway would be short, it could only handle smaller narrow-bodied planes. Whereas the current setup at Heathrow involves using one runway for takeoffs and one for landings, the new runway would be "mixed mode", catering for both takeoffs and landings. At the moment, the takeoff and landing runways are alternated to provide relief for local residents.

Environmental impact

Currently, a cap of 480,000 "air transport movements" per annum is imposed on Heathrow to reduce the effects of noise and pollution (this was a result of the Terminal 5 enquiry). A third runway would mean exceeding this cap; the DfT study suggested removing the cap but retaining the "noise contour cap" of 145km≤. This means that noise is only allowed to reach a certain level over a specified aea around the airport.

It is also expected the increased traffic would further worsen levels of pollution from the M4. A recent scheme proposed putting the M4 in tunnel past Heathrow to overcome the excessive pollution, which exceeds EU pollution targets.

Airport capacity

Current forecasts show that use of the airport will rise from its current level of 64 million passengers per annum (mppa) to the airport capacity of 89mppa by 2030 (this includes capacity created by T5). Adding a runway would increase capacity to 116mppa and air transport movements to 655,000.

New rail transport

In order to provide for more travellers to the airport, the DfT study assumed the following new rail services:

  • Airtrack
    Services via Staines to Reading, Waterloo and Guildford
  • St Albans & Watford
    Requires new tracks between Hayes & Acton. Trains would leave the Great Western line at Acton and then use the Dudden Hill freight line to reach either the WCML or the Midland line. Presumably this would also mean electrification of the freight line.
  • East London via Crossrail
  • Reading via Slough
    This would require a new Western chord at Airport Junction, where Heathrow Express services join the Great Western line.
  • Intercity
    This would involve construction of an open-air station west of T5 to accommodate diesel trains. Intercity services could serve a wide variety of destinations via Reading - in fact the majority of Heathrow's catchment area outside of London is or could be served by Great Western. Access to the new station would not be through the Heathrow Express tunnels but by adpting the existing Poyle freight line to the west of the airport.

New road construction

Significant road improvements would also be needed to cope with an increase in Heathrow's capacity. The DfT study assumes the following road improvements:

  • A4 & M4 Spur in tunnel
    Obviously constructing the new runway and links to the main airport would require parts of the A4 and the M4 Spur to be submerged.
  • New southern highway
    A new dual carriageway (2-lane) in tunnel would link the south of the airport to the M3.

No improvements were planned for the strategic road network (M4/M25) since these were expected to be catered for by existing schemes.

Heavy opposition

All local councils are opposed to the expansion of Heathrow in this way - this includes Hillingdon, Hounslow, Ealing and Spelthorne.

There are also some campaign groups such as HACAN ClearSkies and "NOTRAG" (No to Third Runway Action Group) which are pushing for a halt to Heathrow expansion.


(newest first)
Pollution test passed for third runway
2006-08-07 16:14:49

A downward trend in nitrogen oxide pollutant levels around Heathrow airport means that a key barrier to the construction of an additional runway has been removed. Previously, it had been believed that extra pollutants from additional flights would breach the EU's minimum air quality standards.

Heathrow air quality argument
2006-05-08 09:44:26

British Airways has published the results of air quality tests around Heathrow which show that it is not breaching EU pollution limits, a key barrier to expansion at the airport. However, anti-expansion groups claim that the test method used by BA is classed as inadequate by the EU.

M4 toll mooted to satisfy Heathrow pollution criteria
2005-09-25 17:23:03

A recent study obtained by the Freedom of Information Act shows that a toll of up to £20 would be needed on the London section of the M4 if a third runway were built at Heathrow Airport. The toll would be needed to keep pollution levels from the motorway from rising past levels banned by incoming EU emissions laws as unsafe.

Sixth terminal "inevitable" for third runway
2005-06-06 17:29:47

A sixth terminal will have to be built at Heathrow if the proposed third runway goes ahead. Detailed plans were unveiled yesterday for the third runway, including this sixth terminal. The proposed location of the runway has been moved eastwards slightly, to avoid the demolition of some listed buildings.

Plan for new Gatwick runway
2005-03-29 13:59:08

Airport operator BAA have published plans to build a new runway and terminal at Gatwick Airport in 2019 if plans to construct a third runway at Heathrow fall foul of EU pollution controls.

New Stansted runway "unviable" without Heathrow subsidy
2005-01-24 11:15:34

A second runway at Stansted Airport would be "economically unviable" without cross-subsidisation from Heathrow and Gatwick, according to leaked Treasury documents. Currently against the cross-subsidisation of airports, the Civil Aviation Authority which is the industry regulator would need compelling evidence to change its mind. With no subsidy, the new Stansted runway could put £10 on ticket prices and would reduce low-cost carrier profits massively, possibly ruining the airport's future.

Airport expansion protests at high court
2004-12-14 14:56:50

Coachloads of protesters against plans for extra runways and airport expansion at Heathrow and Stansted airports went to the High Court to challenge the Government on its controversial White Paper on air transport.

Anti-airport expansion campaign starts
2004-10-08 09:09:41

An anti-airport expansion campaign was launched today by Friends of the Earth (FoE), Greenpeace, Transport 2000 and HACAN ClearSkies, a group fighting expansion plans at Heathrow announced recently by the government's Aviation White Paper.

Emissions targets unattainable with airport expansion
2004-06-17 14:57:51

Sir Jonathon Porritt, an environmental adviser to the government, warned that targets to cut CO2 emissions by 60% by 2050 would be unattainable if the government proceeded with its plans for airport expansion, including runways at Heathrow and Stansted.

Study disputes need for third runway
2004-05-07 10:48:10

A recent study by the London Sustainable Development Commission has reported that up to six of the top ten destinations for London air passengers could be well-served by high-speed rail instead, much-reducing the pressure for airports to expand.

Links & Sources

  1. DfT: A new runway at Heathrow ("Future Development of Air Transport in the UK")
  2. HACAN ClearSkies (anti-expansion group)
  3. BAA

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