DraxPower uses Collett to move abnormal loads

Power generation business DraxPower used UK-based specialized transport company Collett & Sons for the relocation of nine 185 tonne transformers.

Collett had to devise a solution for moving each of the transporters, measuring 5.08 metres x 3.5 m x 6.5 m (HxWxL), from Dartford to the Drax Power Station in north Yorkshire, England.

It was decided that each of the loads would be moved in three stages. Firstly, each transformer would be transported individually from Littlebrook to Thamesport, Isle of Grain, where the loads would be consolidated into two roll on, roll off barge shipments delivered directly to the Port of Goole. From here, the transformers would be stored at Collett’s Goole heavy lift terminal prior to the final five mile onward transport to Drax Power Station.

The biggest challenge, Collett said, was transporting these heavy cargoes from Littlebrook to Thamesport.

The company’s consulting division undertook route studies, site visits and swept path analysis reports of several roads and surroundings to ensure a safe, suitable path for the movements. Having liaised with local authorities, councils and constabularies, an agreed route was firmly in place and in March 2016 Collett mobilised its fleet and headed for Littlebrook Power station to begin the first of the transformer moves.

Due to the position of the transformers, Collett had to utilise its specialist heavy duty jacking and skidding system to manoeuvre each of the cargoes. Space limitations at Littlebrook required each transformer to be skidded 6 metres, before turning 90 degrees and skidding a further 18 m to safely clear the confines of the power station’s industrial surroundings. Finally, after jacking and skidding from their original position, the transformers were turned a further 90 degrees into position for loading.

Using Collett’s girder bridge for the initial stage of the project, the first transformer was loaded to the trailer and the convoy began its 24 mile journey. Travelling with three tractor units, two in push-pull formation and one in support, four police escorts and two pilot cars, the convoy left Littlebrook Power Station.

Its overall loaded weight of 390 tonnes (16 tonnes per axle) and 71 m x 5.13 m (LxW) loaded dimensions meant that Collett would be unable to use the bridge over the M25 motorway at Littlebrook Interchange. As a result, a rolling road block had been put into place on both the northbound and southbound carriageways of the M25. This allowed the entire girder bridge to contraflow two roundabouts and use the northbound slip road to gain access to the M25, the company said. Once on the motorway, Collett’s team reversed the entire combination for half a mile (800 m) across the central reservation and along the southbound carriageway allowing access to Exit 1A and onward transport to Thamesport.

Having negotiated 18 roundabouts, undertaken several contraflow manoeuvres, implemented temporary traffic restriction orders and employed manual steering practices at select points along the route, the transformer arrived safely at Thamesport.

Over the following weeks, the remaining transformers left Littlebrook and were safely consolidated at Thamesport. After discharge from the girder bridge, each transformer was stored on stools and load spreading mats portside. Collett chartered the Terra Marique ro-ro barge with hydraulic roadway and ballast system allowing for the vessel to load on different quay heights.

The team set to loading each of the transformers to SPMT and conventional axles and manoeuvred each one to the hull of the vessel. With the loads safely secured, the barge set sail for Goole, firstly carrying three transformers with a second shipment of six to follow in the coming weeks.

With the loads arriving safely in Goole, Collett began work discharging the transformers once again using SPMT and conventional axles to unload at the Port. Each transformer then made the short journey to the company’s Goole heavy lift facility for storage on stools for ease of re-loading.

When required, each transformer left Collett’s Goole Depot and travelled the short distance to Drax Power Station where, once again using specialist jacking and skidding systems, each transformer was carefully manoeuvred into position for storage.

The project had a total of nine girder bridge movements, two ro-ro Barge shipments, nine onward transportation operations and numerous jacking and skidding manoeuvres.