Abnormal loads specialist Collett & Sons delivered two 178-te supergrid transformers from Tilbury Dock in Essex to National Grid’s Biggleswade substation in Bedfordshire. The transport has been completed on behalf of Hyundai Electric UK. 

Each transformer measured 9.0 metres long, 5.4 metres wide and 5.0 metres in height; combining with the trailer for a total vehicle length of 66 metres. Collett utilised their 250Te capacity Goldhofer girder bridge trailer to facilitate the movement of the two transformers to their final destination. The entire project took place over two weeks, with the transport occurring on two consecutive Sundays.

Before 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.

Tilbury Dock to site

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 route in approximately eight hours. The load was accompanied by Collett’s in-house escort vehicles as well as police escorts; initially being escorted by Essex police from Tilbury Dock, then handed over to Cambridgeshire Police at the county border.

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 their heavy-duty jacking and skidding equipment to skid the 178Te 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. Following the same route, the transformer was delivered to the site where it was once again offloaded onto the final plinth.

The 400kV substation includes two transformers that are needed to power the local area. The substation will initially boost power capacity by 80mW, allowing for future residential and employment growth in the Biggleswade area.