October 23 - Collett Transport has used its Scheuerle girder bridge to deliver two 200-tonne transformers to the onshore substation for the UK's Burbo Bank offshore wind farm.

The two transformers were delivered as part of Dong Energy's Burbo Bank extension project, which will extend the existing farm located on the Burbo Flats in Liverpool Bay at the entrance to the River Mersey. Once constructed, the substation will allow the 32-turbine offshore wind farm to connect to the national grid and begin generating power for over 180,000 homes.

SDV UK, which coordinated the transport of the transformers into the UK, contracted Collett to facilitate the ship's discharge at the Port of Mostyn in North Wales, and handled the subsequent transport to site. Two ballast tractors and a 14-axle modular hydraulic flat top trailer were required to complete the first part of the move.

The transformers were first unloaded from the vessel, before being lifted onto the trailer and transported to an agreed holding position at the port, where they were stored on stools until the substation was ready to receive the cargo.

Due to the size of the cargoes - each measuring 11.4 m x 4.4 m x 4.75 m - Collett explained that a specialised delivery method had to be devised in order to navigate the route, which included a number of height and structure restrictions.

The first obstacle arose at the port exit, where the trailer had to travel over a level crossing - this required Collett to obtain official track possession in order to cross the rail track, said the heavy haulier.

Once the modular trailers had left the port, the loads were positioned at a nearby layby, ready for transhipment onto the company's 550-tonne capacity girder bridge for onward transportation one at a time. 

The overall dimensions of the transport combination required extensive route planning, explained Collett, with a traffic management plans and a route analysis undertaken ahead of the project. 

The final route plan highlighted a bridge, which Collett explained was too weak to accommodate the girder bridge and load. Consequently the company obtained a temporary traffic restriction order - which involved a 12-week approval process - so that the cargo could be transported down the opposite side of the A55 dual carriageway, avoiding the bridge and allowing the trailer to re-join the highway in the correct direction.

Travelling under police escort, the girder bridge and its first load travelled through the town of Flint, before being transported around 24 km to the site in St Asaph, where the transformer was unloaded and placed in position using Collett's jacking and hydraulic skidding system. Five days later, the second transformer was delivered to the site and installed in the same way.