Western Rail Approach to Heathrow

The project was announced by the Department of Transport in July 2012.[3] Theresa Villiers, the rail minister at the time, included the project in the High Level Output Statement published in 2012. This stated 'The Government wishes to see a new railway link to give western rail access to Heathrow Airport' but did not commit to the scheme, making it 'subject to a satisfactory business case and the agreement of acceptable terms with the Heathrow aviation industry'.[4]

The Airports Commission has expressed support for the link and included it in its 2014 report on the Expansion of Heathrow Airport.[5]

Network Rail originally estimated that the project could be operational by 2020.[3] In January 2017, Network Rail's estimate was 2024.[1][6] Slough Borough Council has cited 'parliamentary activity' as the reason for the delay but not offered further explanation.[7]

In May 2018, it was reported that Network Rail intended to apply for a Development Consent Order (DCO) in 2019, and the construction would be privately financed.[8] Before submitting this, Network Rail would present the final designs for the scheme in a series of public information events,[9] which were held in early 2020.[10]

The Department for Transport's Rail Network Enhancements Pipeline, published in October 2019, listed the project among those in an early stage of development, awaiting a "Decision to Design" and the completion of an outline business case.[11] In December 2020, Network Rail stated that progress had been paused by the impact of the COVID-19 pandemic on the aviation and rail industries, and that agreement was awaited on a financial contribution from Heathrow Airport Holdings. Therefore, the DCO application would be delayed until at least the winter of 2022.[12]

The proposed route is a new 5.5-kilometre (3.4-mile) railway line that would leave the Great Western Main Line between Langley and Iver before entering a new twin-bore tunnel. The tunnel would pass under Richings Park and Colnbrook and then join existing lines at Heathrow Terminal 5.[13]

Four access buildings will be built along the route to provide emergency access to the tunnels, with two additionally providing ventilation.[13] Realignment of the existing tracks will also be required between Langley and Iver.[13]

The route could potentially mean closure of Mansion / Hollow Hill Lane. The effects of this closure were being investigated by Slough Borough Council.[14]

The Western Rail Approach is, according to the Airport Expansion Consultation, designed to be "independent yet compatible" with the Heathrow expansion.[15][16]

It is envisaged that there would be a service of four trains an hour from Heathrow to Slough and Reading.[13] Earlier publicity also suggested there would be two trains per hour to Twyford and Maidenhead.[17]

Heathrow Express have offered to run services to Reading which would stop only at Slough.[18]

Map of the Western Rail Approach proposal, with the proposed Heathrow Southern Railway also shown.

Other schemes have been proposed to connect Heathrow Airport to the Great Western Main Line. A western link featured in the Heathrow Airtrack scheme, abandoned in 2011.[19]

Another alternative scheme was the Windsor Link Railway, proposed in 2013 and rejected by the government in 2018, which would have provided both western and southern access to Heathrow.

A complementary scheme which could be developed at a later date, or alongside the Western Rail Approach, is the Heathrow Southern Railway, proposed since 2017 to provide links from the airport to the south and south-west.

• Heathrow Airport transport proposals
• Heathrow Southern Railway

• Western Rail Access to Heathrow: the future of rail travel to the airport – Thames Valley Berkshire Local Enterprise Partnership

51.486°N 0.520°W / 51.486; -0.520 (potential Western Rail Approach to Heathrow)