198Te Transformer Transported To Gretna Grid Stability Facility
Collett has completed the transportation and installation of a 198Te transformer from Heysham Port to Scotland’s Gretna Grid Stability Facility.
The Gretna Grid Stability Facility project commenced with Collett receiving the transformer at Heysham Port. Measuring 10.2m L x 3.7m W x 4.8m H, the transformer wasshunted to a secure storage area within the port. The team used a 12-axle flattop trailer to move the unit and lower it onto stools, ready for future transport.
Following the delivery schedule, our team returned to begin loading operations. This time, we used our 24-axle, 350-tonne capacity Scheuerle girder bridge trailer. The trailer was carefully built around the transformer, allowing for self-loading and minimal handling. Once the transformer was securely loaded and escorted by Lancashire Police, the journey to Longtown began.
Police Escort and Complex Route Management
Approximately halfway through the 88-mile route, at Junction 39 of the M6, Cumbria Police took over escort duties. Due to the cargo’s size and the 77-metre overall length, several complex manoeuvres were required. Notably, police temporarily halted motorway traffic to allow the trailer to contraflow on a joining slip road. This ensured the convoy could bypass a weak bridge that was unsuitable for the weight.
However, the final four miles of the journey were not suitable for the girder bridge trailer. Therefore, the transformer was offloaded onto temporary stools at a transshipment point in Longtown. The girder bridge was then demobilised, and the transformer was reloaded onto a 16-axle Self-Propelled Modular Transporter (SPMT). Thanks to its 360-degree steering and vertical lift capability, the SPMT was ideal for navigating this final leg of the route at a controlled 1mph.
Planning, Permits and Route Preparations
In preparation for the move, our Projects department appointed dedicated managers to coordinate all preliminary work. This included applying for road permits, liaising with police and highways authorities, and working closely with local councils. Additionally, we carried out detailed route surveys and arranged tree trimming, cable diversions and outages, and the temporary removal of street furniture.
Moreover, two historical bridges on the route, dating back to the late 1800s, required structural analysis to ensure they could withstand the load. Just before the second structure — Corries Mill Bridge — our team paused briefly to adjust axle heights. Specifically, axles 2 and 15 were raised to alter the weight distribution. This approach was agreed in advance with the structural consultant and the local highway authority.
Upon arrival at the Gretna Grid Stability Facility, our team began the final stage of the operation. Over the course of three days, we completed jacking and skidding the transformer into its final position on the plinth. As a result of precise execution, the unit was successfully installed.
Supporting National Grid ESO’s Stability Pathfinder
This delivery was part of a broader effort at the Gretna Grid Stability Plant Facility. Earlier in the year, we also transported a 234Te stator to the same site. The facility now houses a 60MVA synchronous condenser, which plays a key role in maintaining grid stability. It provides short-circuit power, inertia, and reactive power compensation. Furthermore, as part of National Grid ESO’s Stability Pathfinder initiative, the facility helps address the increasing challenges of balancing renewable energy sources with consistent power delivery.
Reflecting on the project, Eric Crosby, Projects Director at Collett, praised the team’s efforts:
“The Gretna project required meticulous planning and coordination. We’re proud of our dedicated team for working extremely hard and providing a quality service to our customer. 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.”