Lerwick Port Authority’s project to develop an Ultra-Deep-Water Quay (UDWQ) at Dales Voe, giving the UK unique capability and competitiveness, has received a further boost with a positive response from the renewables sector.

Identified in an independent study for the Scottish Government as the optimal UK site for an UDWQ, originally for decommissioning offshore oil & gas structures, Dales Voe is now recognised as a key location for assembly and deployment of large-scale floating installations for offshore windfarms. 

The Scottish Government will contribute £9 million under the UK/Scottish Governments’ Islands Growth Deal towards the estimated £38 million cost.

Maximising the advantages of the deep-water, sheltered voe and its proximity to oil and gas fields and future offshore windfarms, including the nearby NE1 sites, the 100-metre quay at Dales Voe Base will have an initial water depth of 21 metres alongside, with an option to dredge further to 24-25 metres, plus additional laydown.

With its offshore industry experience and strategic location, Lerwick’s advantages include reduced time to windfarms. It will be the only UK port with alongside water depth to accommodate the world’s largest crane vessels and the ‘tow to port’ option for operators to bring turbines in one piece, including substructures, at full operational draft. The UDWQ potential includes eventual decommissioning of turbines.

DIVERSIFYING ACTIVITY

Supporting renewables projects will play an important role in diversifying Lerwick Harbour’s contribution to the UK energy mix and activity generally at the Shetland port.

“The range of users across various sectors has always been one of Lerwick’s main strengths and servicing renewables adds another key strand to operations,” said Captain Calum Grains, Lerwick Port Authority’s Chief Executive. “We have already been the gateway for the turbine components for Viking Energy Windfarm’s onshore project.

“As we transition to net zero, offshore wind has the potential to expand our input to the country’s energy mix. The UDWQ will be ideally positioned to fulfill a pivotal role in development, maintenance and decommissioning. Through our discussions with operators, there are encouraging prospects for Lerwick having a major involvement in the development and operation of the neighbouring offshore NE1 sites.”

DECOMMISSIONING FIRSTS WITH NINIAN NORTHERN

Lerwick Harbour’s reputation at the forefront of decommissioning offshore oil & gas structures has been reinforced by the disposal of the Ninian Northern field production platform topside and jacket in separate successful, record setting projects in Dales Voe.

The world’s largest offshore construction vessel, Allseas’ Pioneering Spirit, entered a UK port for the first time, delivering in single lifts the topside in 2020, returning in 2022 with the 8,500-tonne jacket when it initially manoeuvred alongside Dales Voe base, working at quayside in another UK first to remove equipment from the facility.

Pioneering Spirit ballasted to 28 metres draft where the jacket was then transferred mid-voe to a barge and loaded-in to a heavy-duty pad, developed at the base by the Port Authority. It was decommissioned by the international partnership, Veolia Environmental Services/ Peterson (UK), as was the topside, with load-in weight of 14,200 tonnes.

Captain Calum Grains. Lerwick Port Authority Chief Executive said: “The capacity of the deep-water voe to accommodate the 382-metres long and 124-metres wide Pioneering Spirit, with its support fleet, and the successful operations to load in and dismantle the two Ninian Northern structures were another demonstration of why Lerwick is a leader in the decommissioning market. It is a reputation which will stand us in good stead in the future, not only in oil & gas projects, but also eventually renewables.”