The £14.8bn Crossrail project today reached a new significant milestone with the completion of the permanent track for the Elizabeth line.
Engineers affixed the final rail clips to the track in the eastbound tunnel of the new Whitechapel Elizabeth Line station.
Construction trains are now able to enter the full length of both new tunnels from end to end.
Watch a 360 degree journey through Whitechapel station:
More than 1,000 people have installed 63,000 sleepers, 51,419 metres of rail and over 800 sections of long welded rail to make up the new Elizabeth Line track, stretching over 50km.
Sir Terry Morgan, Crossrail chairman said:
The completion of the permanent track brings us another crucial step closer to the Elizabeth Line opening in December 2018.
We’re delighted to be officially marking this important milestone as it also signifies a great achievement for all the dedicated men and women who are working on the project.
The Elizabeth line will transform rail travel across London and the South East for millions of passengers with faster journeys, less congestion and improved travel links for a better connected London.
The first passenger train on the Elizabeth Line entered passenger service in June, marking a significant step in the project's progress. It was the first trip after eight years of construction work, opening up the route from Liverpool Street Main Line to Shenfield.
The stretch of line between Liverpool Street heading east to Shenfield will be the only part of the line to run, until the next stage opens in May next year. Then, the TfL Rail service will open between Paddington and Heathrow Terminal 4.
The line in its entirety will eventually run between Reading and Heathrow in the west, through London and out to Shenfield and Abbey Wood in the east.
Transport secretary Chris Grayling said today that Crossrail wasn't just a success story for London.
"Crossrail, Europe’s biggest construction project, has created jobs and driven economic growth across the UK with companies based here winning 96 per cent of the scheme’s contracts," he said.