The tunnel would leave the Great Western main line between Langley and Iver, allowing passengers to travel to Heathrow from Reading via Slough without going into Paddington station.
The spur would not only provide direct trains between Reading and Heathrow but also improve access to Heathrow from the south coast, the southwest, South Wales and the West Midlands. It would also reduce congestion at Paddington station, Network Rail says.
The new line would travel above ground for approximately 250 metres before entering the tunnel, which would connect to existing platforms at Heathrow Terminal 5. At its shallowest the tunnel could be approximately 10 metres below ground and at its deepest around 30 metres, with a diameter in the region of six to seven metres, Network Rail says.
An initial informal public consultation process was held during February and March. “We will now analyse all the comments we have received ahead of a second phase of consultation later in the year,” Network Rail said.
The aim is to submit a planning application early next year and start construction by mid-2017. The scheme is expected to take around four years to complete, with trains running before the end of 2021.
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