Safespan Europe is installing an extensive underbridge access system on a major road bridge in the the UK, and it is the first time that its patented technology has been used outside the US. Access International's Lindsay Gale reports from the site

 

 

 

 

 

 

 

 

Perfect Platform

The M1 motorway, one of the UK's major north-south transport arteries, cuts through the city of Sheffield and is carried for 1 kilometre of its route on a two-tier bridge, the Tinsley Viaduct, which also supports parts of the A631 main road. With a combined length of just over two kilometres, this structure was identified as requiring strengthening to cope with current and projected traffic volumes, and an £85 million (US$131.5 million) three-year project is now underway.

        A major problem faced by the contractor, Cleveland Bridge UK, was how to provide access to the underside of both roadways while minimizing the disruption to motorway traffic and surrounding city road, rail and tram systems. Using traditional scaffolding was likely to cause major disruption for an extended period while at the same time imposing undesirable, and possibly unacceptable, physical loads on the structure itself.

        A solution was found in the underbridge access system developed by Safespan in the US and now being promoted in Europe through Safespan Europe, which was established in 2001 as a trading division of Glasgow-based scaffolding specialist Turner Access. After discussions with the client, the Highways Agency, main contractor Edmund Nuttall and Cleveland Bridge, a letter of intent was issued to Safespan Europe for the construction of working platforms under the bridge that gave the company just six weeks for detailed preparations before commencement of installation and for shipping necessary components from Safespan's US manufacturing facility.

         Safespan works closely with its preferred installation partner, CAN Limited, who in the words of Robin Cochrane, Safespan Europe general manager, "provides the high level of rope access skills that we require. The combined team came on-site on 23rd August and just three months later has completed the platforms under the 20 m(65 ft) high upper M1 roadways and the 10m (33 ft) lower A631 eastern roadways. CAN has also fitted the cabling system under the lower western roadway to which the platform modules on the eastern side will be switched once work there is completed. By the end of the project, we expect to have installed some 750,000 ft2 (70,000m2) of platform."

        It has been a major undertaking for all involved; "At its peak, some 45 Safespan and CAN personnel were on site," says Mr. Cochrane, "but once final assembly is complete, including total enclosure of the work areas and the erection of access towers down each side of the viaduct, the site will be handed over to the contractors and their work will commence. Once completed, towards the end of 2005, Safespan and CAN will return to remove the platforms."

        So what has Cleveland Bridge gained from adopting Safespan's patented access system? First, assembly time is an estimated 30 per cent less than for traditional scaffolding solutions; simultaneous access has been gained to multiple spans; disruption minimized; and the need for large storage areas eliminated. The extremely light yet strong (2.5 kN/m2) Safespan® system also minimizes the loads imposed on the structure itself while still being able to support the heavy loads required on the platforms.

        Once the side panels are installed, work areas will be fully encapsulated, providing environmental protection during  shot-blasting and painting operations, and at the same time providing full protection to those below the viaduct - a crucial benefit       given that two railway lines, a tramline and various roads run underneath.

Maximum headroom

The single most important advantage, however, is gained from the fact that adequate clearance is provided below the upper platform to allow the free flow of traffic on the lower roadways while still creating adequate working headroom above.

        Safespan's large open work areas that greatly assist inspection and the controlled access to the platforms provided by the towers will also be a positive boon in these security-conscious times. It will also provide a great working environment. Apparently, two of the contractor's welders had sneaked up to have a look at where they were going to be working and were heard to say that it was the best work site they had ever seen.
   Tinsley is a significant project for Safespan Europe, and the first since the US company entered the European market in 2001. Robin Cochrane, who has lived with the project from the very start, told Access International; "This is the largest project that Safespan has ever tackled since its establishment in 1995, and while the time-scales were extremely tight and the project itself was very demanding, we are extremely proud of the final result. We are certain that the success of this project will lead to further contracts for the Safespan® system."
       Discussions are currently underway on a number of future projects, with Tinsley Viaduct expected to see a number of evaluation visits by potential clients in the very near future. They are likely to be impressed.                                                                    

 

Reprinted with the kind permission of KHL Group Ltd., publishers.