Pioneering Spirit first in-port topside transfer at Dales Voe, Lerwick Harbour from Ninian field.

The removal of the 14,200 tonne Ninian Northern topside offshore was completed by Allseas Pioneering Spirit in under 24hrs in what was the vessels first in-port topside transfer.

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.

Lerwick Port Authority handled the largest offshore structure yet to be decommissioned at the deep-water Shetland port. A newly completed decommissioning facility at Dales Voe base is the location for the dismantling.

The twin-hulled Pioneering Spirit is 382 metres long and 124 metres wide. A bow slot, 122 metres long and 59 metres wide, enables her to move around a platform and lift and transport entire topsides using eight sets of horizontal lifting beams. A 5,000 tonne special-purpose crane is used for lifts, such as lighter topsides. She also undertakes jacket removal and installation.

A 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 purpose-built skid rails.

Dales Voe decommissioning 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. Footage by Rory Gillies/Shetland Flyer Aerial Media.