It weighs in at 1,000 tonnes and needs specially-constructed foundations, but plans to use one of the biggest mobile cranes in the country could be scuppered tonight if the wind is too strong.

The gargantuan crane has been brought in by Bingley Relief Road contractors Amec to lift a new section of bridge, pictured, into place at Crossflats.

The crane will be lowering the specially-made 13 metre-wide bridge into place on the west side of Keighley Road bridge at 2am tomorrow.

And it is not just the crane that is special.

Amec contractors have spent seven weeks making the bridge arch on site as it is too big to transport by road.

The arch weighs 102 tonnes and has been made using 35 cubic metres of concrete and 18 tonnes of reinforcing steel.

If all goes according to plan, the bridge will be lifted up at 2am, swivelled across the road and lowered into place on the foundations.

Put like that it sounds easy, but Charly Clark, Amec project manager, believes this has been one of the most complex parts of the relief road to date.

"The skew of the arch makes the manufacturing of the bridge very difficult. And, of course, creating the arch in situ is quite complex. It's a difficult shape to create in the first place," he said.

Mr Clark said if the wind gets too strong the arch will act as a sail, making it unsafe to carry out the job.

If this happens the crane will have to stay on site till next Sunday morning - the only time of the week when trains are not running on the line and the job can be carried out safely.

The arrival of the crane is causing a real stir among local residents.

It turned up on Wednesday on the back of 18 lorries, and a team has been working since then to put the 28 separate sections together.

Getting a bird's eye view of the whole process is Eric Bastow, 62.

His front garden in Evergreen Walk is only 25 metres away from the crane, and as a former crane driver he has been watching its progress with great interest.

"I've seen some big stuff, but that's the biggest crane I've ever seen," he said.

Around 30 workers will be involved on the night. Providing one of the most important roles will be 40-year-old Julie Vaughan.

She will be keeping her cafe, the Castlefield Cafe, open throughout the night to keep the workers fuelled with bacon butties and cups of coffee.

"We had a few inquiries from the lads asking if we were going to be open," she said.

"At the moment there's going to be three of us working so we have people all through the night. We're planning to keep going on coffee and adrenaline!"