One of the largest mobile cranes in the UK, a 1,500tonne capacity unit, recently positioned nine 90tonne 42m pre-stressed bridge beams by
The massive W-beams were hoisted into place at Junction 5, the Raith Interchange, on Scotland’s M74 motorway – part of the M8-M73-M74 motorway improvements project.
The Raith interchange is a noted pinch point in the Scottish motorway system, so installation took place in three night operations from midnight to four in the morning. The W-beams are among the largest bridge beams of this type fabricated in the UK in recent years. ABM are supplying precast structures to six other bridges on the £500 million project being delivered for Scottish Roads Partnership on behalf of Transport Scotland.
The beams were also the largest pre-stressed beams produced by ABM since a major upgrading of the company’s factory in the mid-England village of Tuxford.
Each W-beam was cast in purpose-built heated moulds ensuring rapid uniform curing to achieve the 50N/m2 stress load transfer strength. Each beam has more than a 1,700tonnes pre-stress load.
The loads were carried by Walker Haulage of Tuxford to the Scottish border - without escort. Local police then escorted the steering bogie trailers to site to complete the near-420km journey.
