Freyssinet Ltd

Using Freyssinet's Autoripage® technology, this video shows the 'slide' of a 6000 tonne box structure across a railway, which took place in December 2024. The Radlett Strategic Rail Freight Interchange (SRFI) development involves the construction of a new rail to road freight depot near St Albans. The project requires the design of a new rail connection to the Midlands Main Line (MML), including an embankment to support the new rail chord, and an intersection bridge (underbridge) allowing the new rail chord to pass underneath the four tracks of the MML.

Innovative specialists in structural enhancement, repair of bridges, buildings and civil engineering projects. Design, supply and install across the UK. Freyssinet has been at the forefront of specialised civil and structural engineering technology, consultancy and installation since 1950. A leading specialist in concrete repairs, bridge bearings, post-tensioning, expansion joints, jacking, cathodic protection and sprayed concrete, Freyssinet is renowned for delivering innovative solutions and pushing the envelope of structural and civil engineering

The world longest box bridge slide took place over Christmas 2022 to enable the HS2 railway line to cross over the M42 motorway in Warwickshire. In collaboration with Balfour Beatty Vinci (BBV) teams, Freyssinet worked around the clock over the Christmas period to move the 12,600-tonne bridge structure over 163 metres and into position. Freyssinet designed and implemented the sliding mechanism, utilising its Autoripage® technique for heavy handling, which enabled the box to be pushed on a guiding raft and into place. The box bridge slide operation took place between 24 and 26 December. Progressing at four metres per hour, the box was moved into position in under 36 hours, completing well ahead of the programmed schedule. This enabled BBV to proceed with subsequent works and reopen the M42 a day ahead of schedule.

reyssinet’s ElevArch® technique was trialled in a live demo in front of 120 guests from the rail sector, including Network Rail, Aktins, Arup, Arcadis, DfT and J. Murphy Group. The 161-year-old, 220 tonne masonry arch bridge on Moco Farm in Buckinghamshire was successfully raised 900mm using ten 50 tonne jacks. Freyssinet was invited to participate in RSSB’s Innovation Programme for The Avoidance of Bridge Reconstruction in 2014. From this, the company’s innovative ElevArch® concept was born - a revolutionary technique for vertically jacking masonry bridge arches, designed to minimise intrusion to the rail environment compared to other techniques, significantly reducing cost, time and resources. The ElevArch® lift trial was the result of two years of innovative thinking and careful planning.

The A465 Saltings Viaduct on the Neath Interchange is a busy dual carriage way, bringing traffic to and from the Swansea area. Assessment of the viaduct indicated that essential maintenance was required to replace the expansion joint located on the east side of the bridge on both the westbound and eastbound carriageways. Freyssinet was appointed by the client, Cemex, on behalf of South Wales Trunk Road Agent (SWTRA) for the Welsh Government to design, supply and install a new expansion joint on the bridge. Thousands of vehicles use the bridge every day and as such, every effort was made to minimise inconvenience to road users. Freyssinet installed a cover plate system, which allowed traffic flow during day time hours and the work was completed during night time closures. After removing the existing joint, Freyssinet’s in-house hydrodemolition team Aquaforce removed the surrounding concrete, before installing a fully galvanised Freyssimod LW 480 modular type joint, featuring new swivel bearing supports which allows good operation for whole life.