A 131-tonne shunt reactor reached National Grid’s Trawsfynydd Substation in North Wales following a carefully sequenced operation combining sea transport, a tidal beach landing, abnormal load movement and final skidding into position.
Collett carried out the project on behalf of Royal SMIT B.V., transporting the 7.2 m long, 4.2 m wide and 3.9 m high reactor on a 12-row modular drawbar trailer.
The operation began at the Port of Rotterdam, where the reactor was loaded directly onto Collett’s trailer positioned inside the Terra Marique, operated by Wynns & Sons. Once secured, the vessel sailed to the Welsh coast.
Because significant inland route restrictions ruled out a conventional delivery route, Black Rock Sands was selected as the landing point.
The beach discharge then had to be completed within a 12-hour tidal window.
As the tide receded, around 290 metres of temporary trackway was installed across the beach. A purpose-built ramp was also constructed between the vessel’s tail lift and the trackway to accommodate the modular trailer’s suspension during the offload.
The reactor was then driven directly from the vessel, across the beach and above the high-water mark. Once the load was safely clear of the tidal zone, the temporary ramp and trackway were removed before the tide returned.
From Black Rock Sands, the reactor continued by road under North Wales Police escort along a pre-assessed route to Trawsfynydd Substation. Preparatory works included tree pruning and route planning to negotiate restricted rural roads and steep gradients.
Ahead of its arrival, Collett’s Heavy Lift team constructed a 12-metre skid track at the substation.
Hydraulic jacks were then used to transfer the reactor from the modular trailer onto the skid system. Because the site’s bund wall could not carry the load, steel beams were installed to bridge the obstruction and spread the weight safely.
The reactor was subsequently skidded into its final position and jacked down onto its plinth.
Collett also managed the transport and installation of the associated cooler bank equipment. These components were collected in Rotterdam, moved through the company’s Goole depot and delivered separately to Trawsfynydd, where a 90-tonne mobile crane handled the final offload.
The project brought together marine transport, tidal planning, abnormal load logistics, skidding and heavy lift engineering in one coordinated delivery sequence.
