Ready for decommissioning at Shetland port following delivery by Pioneering Spirit
The operation to load-in the 14,200 tonne Ninian Northern topside at Lerwick Harbour's Dales Voe Base has been completed successfully.
The structure arrived from the North Sea field on Friday on Allseas' construction vessel, Pioneering Spirit, following a swift single lift offshore.
In the deep-water voe, the topside was transferred immediately onto Allsea's Iron Lady cargo barge and then moved to quayside.
After only eight hours on her first visit into a UK port, Pioneering Spirit, the world largest heavy lift vessel, departed for Rotterdam, three hours ahead of schedule.
The complex operation to slide the topside 185 metres from Iron Lady to a newly-built heavy duty concrete pad, was undertaken over two days. The process involved synchronising the barge to the quayside to remain absolutely level and a push/pull system of hydraulic engines sliding the total transfer weight of 16,200 tonnes, including skid equipment, along a purpose-built skid rails.
The pad has an impermeable surface with a 60 tonne per square metre loading, which matches the quayside capacity. The unique quay design has an 800 tonne per metre line loading which enabled the transfer of the topside from the barge.
Captain Calum Grains, Lerwick Port Authority Chief Executive, said: "The successful delivery of the topside by Pioneering Spirit and the smooth operation to safely move the deck onto the Base is another demonstration of the port's capacity and capabilities to handle large decommissioning projects.
“Plans in the pipeline, including for an Ultra-Deep-Water Quay at Dales Voe, will significantly expand our potential to support both decommissioning and renewables.”
Lerwick's biggest project yet, dismantling the Ninian Northern topside will be carried out by Veolia/Peterson, a leading industry partnership with a target over 97% reuse/recycling for the structure.