Clearing the deck

Mr Brown praised engineers’ efforts so far as they showed him progress from high up on the north abutment. Looking out over the Forth, where the new bridge’s three main towers have shot up over the past 12 months.

Mr Brown said:

“This time last year the view across the Forth looked a lot different. Work on the foundations was finishing last summer and the beginnings of the towers themselves started under the water line.

“The progress being made by the men and women building the new bridge is truly impressive. All three of the towers are now at or past the level of the bridge deck. Initial temporary supports and first bridge deck sections are due to be fitted to the Centre Tower’s complex and reinforced “power joint” in the autumn, while work on all three towers continues until they reach their full 210 metre height next summer.

“We can also see the v-shaped support piers for the South Approach Viaduct rising and being completed as the months go past. As each one is erected, the viaduct is then launched further out from the shoreline across the pier. The viaduct has already been launched more than half of its final length.

“Meanwhile on the south road network, the new Queensferry junction is nearly complete and expected to be open shortly. Overall the project remains on schedule and under budget.”

Recent construction at the deck level of the Centre Tower, known as the "power joint", is the most complex area of any of the towers. It is where the bridge deck will be fixed securely to the Beamer Rock-founded tower, with all the natural expansion and contraction being taken up by large expansion joints at the north and south ends of the bridge. This allows for a continuous smooth road surface to be laid across the length of the crossing.

There’s no requirement for similar joints at the North and South towers, as the deck is only secured to these using sliding bearings which provide lateral stability, with the deck expanding and contracting around the towers.

By the end of this year, assembly equipment will be moved over from the South Approach Viaduct area to the north to start assembly of the shorter North Approach viaduct steelwork. This is expected to be launched into position later in 2015.

Work on the road network connections to the south and north continue to progress well with the new Queensferry gyratory due to open shortly to realign the A904 and work in the Ferrytoll area for the new M90 and local roads layout also clearly taking shape.