MORE than 30 workers sacrificed their Christmas dinners in a race against the clock to pull down a rail bridge over the weekend.

In an operation timed to the minute, engineers demolished the Relley Bridge, which spanned the East Coast Main Line, on Christmas Day and Boxing Day.

They fought to collapse the Victorian structure, which was on the outskirts of Durham City, before trains began running on the line once more today.

Durham County Council commissioned the demolition after discovering that the stone bridge's five arches, built to carry horse-drawn carts from Durham to villages in the Deerness Valley, were crumbling under the weight of heavy modern vehicles.

Mike Ford, business manager for the council's bridges and contract management division, led the project.

He said: "This was the only time we could do it. We have had this project booked with Network Rail for a couple of years, but it was still a race against time to get the line cleared."

The complex operation required specialists from Jarvis to take down overhead power cables, before engineering experts from Balfour Beatty moved in and laid down a "crash mat" covering the rails under the bridge and ten metres to both sides, to protect the track.

This team handed over to a demolition crew, from contractors MGL. Using heavy machinery, they pulled down Number Four Arch, significantly weakening the 132-year-old structure, then knocked down the rest.

They then had to remove more than 3,000 tonnes of rubble, made up of about 1,400 tonnes of stone blocks and 1,600 tonnes of fill from inside the bridge.

Once this was completed, the crash mat was removed and the overhead lines reinstated.

All this had to be completed before the first train was due to pass through from Durham at 4.30am today, bound for London Kings Cross.

The Relley Bridge was built in 1872, when the East Coast Main Line (ECML) was laid.

It passed over a stretch of rail track known as "the Crewe of the North", because it marked the joining of three main lines and several branch lines with the ECML, requiring complex junctions.

The first line built there was the Bishop Auckland to Durham City route, in 1856. This was joined in 1858 by the branch line to Ushaw Moor, near Durham.

In 1862, the Consett line along the Lanchester Valley was extended, and, in a feat of Victorian engineering, travels underneath the Bishop Auckland line to join the ECML.

Up until this weekend, the bridge carried the B6302 road over the line, near the hamlet of Stonebridge. But despite its historic role, Mr Ford said it was outdated and not easy to use.

"For a road bridge, it was very impractical," he said.

"There were absolutely no facilities for pedestrians.

"It was only 6.2 metres wide from parapet to parapet, where a modern carriageway is 7.3 metres. It is seventy metres long, so if you were a pedestrian, you had to be Linford Christie to get across before a vehicle came along.

"From the side, it looked like a lovely bridge which should be preserved. But it was falling down and its replacement was Network Rail's top priority in this region.

It has already been replaced by the county council with a £3m structure, which opened last month. But the stone from the old structure will not go to waste.

"We are keeping a certain amount to use in repairs elsewhere," said Mr Ford.

"The rest will be recycled in one way or another, either as bricks or fill for other works."

Last night, Peter Stephenson, clerk of works for Durham County Council, said: "Everything went according to plan and without a single hitch and, in actual fact, we finished ahead of schedule."