The milestone represents the first of four closures between the “deck fans” now nearing completion around each of the bridge’s three towers.

By connecting the viaduct and north tower deck of the Queensferry Crossing a massive temporary structure measuring approximately 600 metres long and weighing approximately 30,000 tonnes has been formed.

It comprises over 10,000 tonnes of steel and 20,000 tonnes of concrete while 46 stay-cables have been installed to hold the bridge deck in place - each cable contains up to 109 high tensile strands which are individually threaded and tensioned.

The contractor Forth Crossing Bridge Constructors (FCBC) has installed 22 deck sections on the north tower, each weighing on average 750 tonnes. The north approach viaduct, weighing approximately 6,000 tonnes, has been pushed out over 200 metres. Now, the final 700 millimetre gap between the two has been closed, connecting the bridge to land.

Economy Secretary Keith Brown visited the site today and was among the first to walk from the land on to the bridge.

He said: “This is a historic and symbolic moment in the building of the Queensferry Crossing.

“We’re all witnessing engineering on a truly epic scale on this project, with over 30,000 tonnes of concrete and steel used just to build this part of the bridge. Despite the massive size and weight of the bridge completing the closure between the viaduct and bridge deck is a delicate operation involving extremely precise tolerances for fit up.

“The progress being made on the Queensferry Crossing and its approach roads continues to demand skill and dedication from everyone involved. The Firth of Forth presents challenging weather conditions right throughout the year and I’m sure I speak for us all when I sincerely thank all of those hard-working people for getting us to this point.

“I am pleased to update that subject to weather conditions, the project remains significantly under budget and on track to open in May 2017 in line with the revised programme and the contractual completion date.

“Overall, nearly 79 per cent of the total bridge deck is now in place, the final section of deck is having its concrete deck cast in Rosyth today, meaning all the deck is ready to be lifted into place on the bridge. On the roads two lanes of traffic are being maintained on the A90 despite the significant roadworks underway at Ferrytoll junction. While on the south side the finishing touches are being applied to the road connection with surfacing and overhead gantries being installed.”

Michael Martin, FCBC project director, said: “The first closure on any bridge project is always a significant milestone. On this fantastic project, this closure represents leading edge civil engineering.

“After installing the last road deck section and connecting it to the expanding North Tower road deck, we then had to close the remaining gap on the north – or landward – side. This was done by pulling the northern approach viaduct 700 millimetres southwards. This was a massive and, at the same time, very delicate operation. Massive because the viaduct is 222 metres long, weighs approximately 6,000 tonnes and had to be pulled up a gradient of about 3 per cent. Delicate because the tolerances the team were working to were tiny – just a few millimetres either way. Happily, it all went very well. We now look forward to the remaining closures in the months ahead.”

The Queensferry Crossing is due to open in May 2017, months later than initially planned.