The Scottish Parliament has voted overwhelmingly to replace the historic, but rapidly corroding, Forth Road Bridge, sparking environmental protests and calls for an investigation to save the engineering icon.
The Parliament voted 108-3 on Tuesday (Dec. 15) to replace the bridge, saying that additional corrosion of the structure’s main cable could force vehicle bans.
Opponents, however, call the plan a “£2 billion punt,” saying anti-corrosion measures now underway could save the bridge.
‘Biggest Single Project in Scotland’
Transport minister Keith Brown led the charge for the Forth Crossing Bill, calling a new Edinburgh-Fife bridge over the Firth of Forth “absolutely vital to ensure Scotland’s economic well-being.” The Parliament’s Forth Crossing Bill Committee unanimously backed the plan.
The main towers, shown here under construction, were strengthened in the late 1990s to handle the ever-increasing vehicle weight on the bridge.
“The construction task itself will be huge,” Brown said during the Parliamentary debate on the new span, which would run adjacent to the current bridge and cost £2.3bn (about $3.6 billion US). “It will be the biggest single project in Scotland for a generation.”
Construction is expected to begin in 2011 and be completed in 2016.
The main cables are anchored at each end; each supports a 13,800-ton load. The anchorages, shown here under construction, are concrete, cast in tunnels between 56 and 79 meters long.
The Forth Road Bridge is considered an engineering marvel. The long-span suspension bridge was the largest in the world outside the United States when the bridge opened in 1964. With the approach viaducts, the bridge is just over 2.5 km (about 1.6 miles) long.
The bridge carries 24 million vehicles each year-far more than expected when the structure was designed in the 1950s.
Barry R. Colford, Chief Engineer and Bridgemaster for the Forth Estuary Transport Authority, detailed the bridge’s corrosion problem in a May 2010 article in JPCL: Journal of Protective Coatings and Linings.
|Today, the bridge carries about 24 million vehicles each year.|
The bridge bill had the support of Scotland’s three main opposition parties, but the Greens opposed it as a costly gamble. Efforts are currently underway to arrest the bridge’s corrosion, but those results will not be known until 2012.
“We’ve been told not to take a gamble with Scotland’s economy, but I think this is a £2 billion punt,” said Green MSP Patrick Harvie. “And it’s not just the economy being put up as a stake, but also our social objectives.”
World Wildlife Federation Scotland, Friends of the Earth Scotland and other environmental groups have also mobilized to fight the plan and save the bridge.
Their new coalition, The ForthRight Alliance, called Wednesday (Dec. 16) on the Auditor General for Scotland to launch an urgent investigation into alternatives to the project, such as strengthening the existing bridge, before contracts are signed.
“[T]here are risks associated with this project for all concerned if such an audit is not carried out and its advice taken seriously,” the letter said.
‘Disappointment and Anger’
Vehicle restrictions on the bridge have been discussed but generally rejected, given the span’s importance to the economy. The bridge’s main towers were already reinforced in the 1990s to handle the increased traffic.
Officials say trucks would have to be banned from the bridge by 2017 if the corrosion continues at the current rate.
Brown predicted “dire economic and social consequences” if the bridge is restricted or fails.
South Queensferry’s local Liberal Democrat Margaret Smith tried unsuccessfully to amend the bill by controlling noise and disruption from the project and joined the Greens in opposing the bridge.
“There is a real sense of disappointment and some anger amongst my constituents, who feel that they have been ignored,” Smith said.