Upper Forth Crossing at Kincardine (Clackmannanshire Bridge)

An ongoing increase in traffic density on Kincardine Bridge gave rise to a public inquest designed to find solutions to relieve traffic congestion over the Firth of Forth span and around the town of Kincardine-on-Forth. The solution put forward by VINCI Construction Grands Projets was to build a new bridge northwest of the existing span, thereby bypassing the city of Kincardine. The consortium then built a 1,200-metre incrementally launched bridge over the Forth River along with 5.3 kilometres of roadway, 3 interchanges, and 4 standard engineering structures. The bridge connects 2 major thoroughfares north and south of the river, thereby providing traffic relief in this region located 40 kilometres northwest of Edinburgh.

BACKGROUND

An initial crossing over the Firth of Forth at Kincardine was opened for traffic in 1936. The Scottish government decided on the construction of a new bridge, known as the Upper Forth Crossing At Kincardine, upstream from the existing span. This new crossing was used initially only to allow repairs to the existing bridge. Once both bridges were in service, the result was improved traffic flow thanks to the separation, on the one hand, of traffic in southern and northwestern Scotland, and, on the other, southern and northeastern traffic. The advantage of the “two-bridge strategy” is that it makes optimal use of existing infrastructure (a 70-year-old bridge that is 500 m long), relieves Kincardine of excess traffic from the west and east, and paves the way for economic benefits while providing a solution with a low environmental impact. The new bridge is nearly twice as long as the old one due to its 45° inclination with respect to the south bank of the river.

TECHNICAL OVERVIEW

The 1,200-metre bridge, which has a 35,000-tonne concrete deck, was built and launched from the north bank of the river. This considerably reduced the space required for the worksite and the environmental impact of the project during the implementation phase. All work activities were carefully monitored to comply with the ecological and environmental requirements of the Firth of Forth Islands Special Protection Area (SPA).
The bridge and its access structures are located in an area that receives special protection under the European Union Directive on the Conservation of Wild Birds. This part of the estuary at Kincardine is made up of soil with high nutritional quality that attracts a large number of migratory birds that hibernate in the region – this bird population had to be protected from all temporary and permanent damage. As a result, the footbridges connecting the shore to the bridge piers were covered in a green net to “hide” people and avoid frightening the birds. Similarly, neon lights were preferred to conventional lights, resulting in lighting that is less harsh.
As part of Great Britain’s biodiversity plan, embankments protecting this former power-generation site were removed in order to create 8 hectares of salt marshes and mudflats as well as an island designed for the birds. Since August 2007, these 8 hectares have been returned to nature and are, once again, subject to the tides. Inspections show that the area has been repopulated with many invertebrates and birds. Another key feature of the project was its use of recycled materials: byproducts from power-generation stations and mining activities were used on the project site as backfill material. A total of 750,000 tonnes of such material was used, which means that it didn’t have to be quarried. On this project, over 85% of waste products were recycled.

The structure we put forward was selected because it provides a more effective response to the project’s significant environmental constraints. To the south, it limits the impact on salt marshes and flood-prone areas and, to the north, it makes optimal use of an area freed up by the demolition of a decommissioned power-generation station.

 

IMPACT

Work on this new crossing, renamed Clackmannanshire Bridge, began in June 2006; it was opened to traffic in November 2008. At the time, the main span was the world’s second-longest incrementally launched structure (a total of 1,188 m from only on direction). Based on detailed design, construction – from the first pier to pavement joints – was achieved in just 2 years, providing an excellent example of effective technical cooperation among the work teams. Throughout the project, we were able to put into practice innovative solutions to meet demanding specifications in terms of quality, safety, on-time performance, and environmental protection. The need to preserve the environment of the Forth River was a constant concern throughout the construction of the Kincardine Bridge. This world-class project has relieved traffic congestion and provided road users in Scotland with a high-quality roadway network.

Project participants

Client
Transport Scotland (Scottish Executive)

Project management
Transport Scotland (Scottish Executive)

Key figures

Implementation dates
June 2006 to December 2008    

Earthworks
791,300 m3

Concrete
37,600 m3

Reinforcement
10,268 t

Testimonial

“This bridge is a world-class infrastructure project that will reduce travel time, improve the roadway network in central Scotland, and provide a single access to the counties of Clackmannanshire, Fife, and Falkirk.”

ALEX SALMOND, FIRST MINISTER OF SCOTLAND AT THE INAUGURATION OF THE BRIDGE

Awards

Scottish Transport Awards:
Transport Project of the Year

Highways Magazine Awards:
Major Project Award

Chartered Institution for Highways and Transportation:
Highly Commended, “Major Projects” category

“Saltire Award for Civil Engineering”

Awards

CEEQUAL:
Whole Project Award “Very Good”

Structural Awards:
“Award for Transportation Structures”

“British Construction Industry Major Project Award”:
Highly Commended

Post-Tensioning Association price

Green Apple Award (silver category)