WORKERS are poised to put in place the final few metres of the record-breaking Queensferry Crossing but only after a stormy year spanning the Firth of Forth.

The last two decks - each weighing 750 tonnes - will be raised into position by crane within weeks, reaching across the last few metres to Fife in Scotland's biggest transport infrastructure project in a generation.

Built on three giant steel cylinders, each the size of a six-storey block of flats, the bridge is the longest of its kind in the world with the highest towers in Britain but the gargantuan project has also brought controversy and an independent investigation into pay and conditions for the 1,300 workers has been launched in the final stages of its five-year construction

The £1.4bn bridge - a cut-price bill from the earlier estimate of £1.7bn-plus - is on course to open in May, about five months later than planned, as a result of bad weather.

Other setbacks like having to call in the bomb squad after suspected explosives were found by workers also brought delays.

In April tragedy struck when 62-year-old construction worker John Cousin, from Northumberland, was killed when he was reportedly struck by a crane.

Workers have twice walked off the job over pay and a number of allegedly illegal immigrants were hauled from the site.

The operation is now to be probed by conciliators Acas who were called in by transport secretary Keith Brown after a raft of concerns were voiced.

The construction has been kept under close scrutiny by Neil Findlay, Lothian Labour MSP, who raised claims some sub-contractors were paid £4 an hour below the industry minimum, although the main contractor Forth Crossing Bridge Constructors said it had been assured appropriate local rates were being paid.

Mr Findlay welcomed the Acas audit saying there are "a number of outstanding issues to be addressed" while the construction industry union UCATT Scotland warned the project faces "sinking under a tide of infamy".

However, it is hoped when it is complete the bridge will bring a range of benefits.

The Forth Road Bridge will be dedicated to public transport, pedestrians and cyclists which it is hoped will mean bus journeys across the Forth will be quicker, while it will also bring a major improvement to the trunk road network in the east of Scotland.

As well as the direct link to Edinburgh and the Lothians the roads revamp will mean a boost to the connection from Fife to Glasgow and the south west of Scotland, potentially improving journey times across the country.

The man in charge of the project, David Climie, of Transport Scotland, said that the bridge is "now close to completion".

He said: "The deck is now continuous from the north viaduct in Fife to just a few metres shy of the south viaduct in South Queensferry.

"Only two deck segments remain of the 122 total and these will be lifted in early 2017.

“The focus next year will be on the final few concrete pours to complete the deck of the south viaduct.

"This will be followed by and then road surfacing and the final fit out of all the mechanical and electrical systems on what will be a truly state-of-the-art bridge."

Mr Climie continued: "Our challenges with the weather have been well documented and it is to the enormous credit of a skilled and dedicated team that the project remains on schedule to open within the original contractual timeframe and significantly under budget.

"Of course, no one ever said building the tallest bridge in Britain in such a challenging environments was going to be easy.

“Our entire focus is on completing the construction and travellers in the east of Scotland can look forward to significant improvements when the bridge is open."

He added: "he projects brings a continuous 14 mile motorway from the outskirts of Edinburgh to Dunfermline, with significantly improved junctions and smart technology to vary speed limits to easing periods of congestion.

"In addition, the Forth Road Bridge will be retained to complete a dedicated public transport corridor which will improve bus journey times and a much improved, largely traffic-free environment for cyclists and walkers across the Forth.“