Collett & Sons Successfully Transports 198Te Transformer To Gretna Grid Stability Facility

Collett and Sons Ltd, a UK based leading specialist heavy transport, has successfully completed the transportation and final installation of a 198Te Transformer from Heysham Port to Scotland's Gretna Grid Stability Facility. The project commenced with Collett receiving the Transformer at Heysham Port. Measuring 10.2m L x 3.7m W x 4.8m H, the Transformer was shunted within the port to a secure storage area utilising Collett's 12-axle flattop trailer and lowered onto stools, ready for future transport.

As per the delivery schedule, Collett's team returned to the storage area to commence loading operations. Utilising their 24-axle 350 Tonne capacity Scheuerle girder bridge trailer, the team strategically built the trailer around the Transformer, ensuring efficient self-loading and minimal handling of the cargo. With the Transformer securely loaded and escorted by Lancashire Police, the team began the journey to Longtown.

Approximately halfway through the total 88-mile route to the transshipment site, at JCT 39 M6, escort duties were transferred to Cumbria Police. Given the weight of the cargo and its combined length of 77 metres with the girder bridge trailer, Collett executed several complex manoeuvres to ensure the Transformer's safe passage. Notably, the Police halted motorway traffic to facilitate a planned manoeuvre, enabling the girder bridge trailer to contraflow on a joining slip road and bypass a weak bridge structure.

Due to the road conditions along the final 4-mile journey not being suitable for accepting the negotiability of the girder frame trailer, the Transformer was self-off-loaded onto temporary stools at a transshipment point in Longtown. The girder frame was then demobilised, and the Transformer was loaded onto a 16-axle SPMT (Self-Propelled Modular Transporter). With its 360-degree steering and vertical lifting capability, the SPMT was ideal to navigate this final part of the route to site at a controlled 1mph pace.

Prior to the commencement, Collett's Projects department appointed dedicated project managers to coordinate all preliminary works including applying for road permits, liaising with police authorities, highways authorities, local councils and conducting detailed route surveys. These efforts ensured clear passage by arranging tree trimming, cable diversions & outages and temporary removal of street furniture along the route. Additionally, a thorough structural analysis was done to verify if two bridge structures on the route, which dated back to the late 1800s, could support the combined weight of the SPMT and Transformer.

Just before the second bridge, named Corries Mill bridge, the Collett Team had arranged to temporarily stop and raise axles 2 and 15 on the trailer, to alter the weight distribution when crossing the bridge. This was the solution finalised with the structural consultant and the local highway authority during the planning stage. Upon arrival at the Gretna Grid Stability Facility, Collett's scope of work also included positioning the Transformer onto its designated concrete foundation.

Over the course of three days, Collett's heavy lift team executed the final operation. It began with jacking up the Transformer from the SPMT trailer to position a skid track underneath it. The Transformer was then skidded along the track until it was jacked up once more to remove the skid track.

Finally, it was carefully jacked down, ensuring precise placement onto the final plinth utilising positioning plates. The Transformer delivery by Collett is part of a broader project to deliver to Gretna Grid Stability Facility, which also included the successful transportation of a 234Te Stator earlier in the year. This facility, equipped with a 60 MVA synchronous condenser, plays a crucial role in stabilising the grid by providing short-circuit and inertia power, along with reactive power compensation.

As part of National Grid ESO's Stability Pathfinder initiative, Grid Stability Facility addresses the growing challenges of maintaining grid stability in a system increasingly reliant on renewable energy sources, showcasing the shift from conventional power generation to sustainable energy solutions. Eric Crosby, Projects Director at Collett & Sons, commented: ''The Gretna project required meticulous planning and coordination.

I'd also like to extend our gratitude to Lancashire and Cumbria Police for escorting the convoy, as well as to the local authorities and supporting service providers, whose assistance helped ensure a safe and smooth delivery.''