Collett delivers supergrid transformers to Biggleswade

Each transformer measured 9 m x 5.4 m x 5 m. Using Collett’s 250-tonne capacity Goldhofer girder bridge trailer, the total vehicle length reached 66 m. The entire project took place over two weeks, with the transport occurring on two consecutive Sundays.

Prior to the transport, Collett’s projects and consulting departments provided comprehensive planning and site visits to strategise the route. This included a comprehensive route survey, as well as swept path analysis reports, identifying obstructing street furniture that would require temporary removal. Collett liaised with both Cambridgeshire County Council and Central Bedfordshire Council to ensure that the movement would be successful.

With Collett having undertaken all ship chartering operations, the two transformers arrived at Tilbury Dock. Here, the first transformer was discharged from the vessel onto the girder bridge trailer where it was lowered onto stools in a secure storage area to await future transport.

The second of the two transformers was discharged directly onto the girder bridge trailer in preparation for the first delivery to commence.

Departing from Tilbury Dock, Collett travelled along the 76-mile (122 km) route in approximately eight hours. The load was accompanied by Collett’s in-house escort vehicles as well as police escorts.

Upon arrival at the site, Collett was responsible for offloading the transformer. Having previously undertaken detailed planning – including ground bearing pressure calculations, method statements, risk assessments and installation drawings – Collett’s heavy lift team utilised its heavy-duty jacking and skidding equipment to skid the transformer directly from the trailer onto the final plinth.

With one of the two transformers successfully delivered, the girder bridge was de-mobilised and returned back to Tilbury Dock to load the second transformer.