Queensferry Crossing to open after 10-year 'challenge'

Helicopters have been airlifting heavy machinery from the towers of Britain's tallest bridge ahead of its opening this week.

The Queensferry Crossing over the Firth of Forth, north of Edinburgh, is the longest free-standing balanced cantilever bridge in the world.

Its towers stretch 210 metres into the sky, making it the tallest bridge in the UK.

Traffic will be able to use the crossing this week, ahead of its official opening by the Queen on 4 September.

It will be 53 years to the day since the Queen opened the first Forth Road bridge in 1964 and she'll be accompanied - as she was then - by the Duke of Edinburgh, in his first official appearance since he retired from solo royal engagements last month.

The Queensferry Crossing stretches 1.7 miles between the banks of the Forth and is the result of a 10-year project involving 35,000 tonnes of steel, 150,000 tonnes of concrete, 23,000 miles of steel cabling (almost enough cable to stretch around the equator), and a workforce drawn from 24 countries, coordinated with the help of a team of translators.

Michael Martin, the project director of Forth Crossing Bridge Constructors, told Sky News: "People always think of the engineering challenges but, for me, one of the most difficult challenges that I have is ensuring that I get the right people working in the right way so that the expertise that they have can be brought together in a team, which is an international team which has never worked together before.

"This has been a challenging job from the outset - building the towers, the tallest bridge towers in the UK, in very hostile conditions. You are basically in the North Sea and the wind conditions, in the winter in particular, are truly horrible.

"There isn't a day goes past where you don't get something thrown at you, a problem to be overcome. But that's what engineering is about. It's been pretty stressful on occasions, I've lost a few nights sleep, but you overcome that.

"Once we're finished... traffic is on the bridge... I'll be immensely proud and I know all my colleagues will be immensely proud of what we've achieved here."

The new bridge stands close to the iconic Forth (rail) Bridge, built in 1882, as well as the original road bridge. It represents a trilogy of engineering excellence through the centuries. The new road bridge will be used by private vehicles, while the old one will accommodate public transport, cyclists and pedestrians.

High winds have often affected traffic on the first road bridge, causing closures and restrictions. The new one has perspex wind shields fitted on the side.

Mike Glover, technical director of Forth Crossing Bridge Contractors, told Sky News: "It acts as a wind scoop. As the wind approaches, it says 'mmm... the pressure's building up', and it pushes itself over the top. Some of it comes through but because we've left gaps in between it acts like a grill.

"The wind comes through not as gusty turbulence, it comes through as a linear flow of air. So the combination of the scooping over and the air coming through as a linear straight line is what gives it a much more enhanced environment than you get on the existing bridge."

The new bridge has been completed nine months behind schedule. It had been due to open last December, but adverse weather conditions have contributed to delays. The cost of construction is £1.3bn, far less than the original estimate of £2.3bn.

The new bridge opens to traffic for the first time on Wednesday. It will then close on the 2 and 3 September for the Queensferry Crossing Experience, when 50,000 members of the public, won tickets in a ballot, will walk across the structure.

On 5 September, an additional community day has been added, giving around 10,000 more people from local schools and community groups on both sides of the Forth the chance to walk on the bridge.

From 6 September onwards the Queensferry Crossing will re-open to traffic, with no pedestrian access.