There are concerns for the safety of crew aboard the Foinaven floating production, storage and offloading (FPSO) ship ahead of planned strikes this week.
Unite has accused Altera Infrastructure of maintaining a “wall of silence”, and “repeatedly” refusing to respond to worries raised by the trade union.
Specifically, the organisation is concerned about the services provision for Foinaven if it comes into distress or if a fire breaks out while it travels to Hunterston Port.
Striking workers will remain on the ship until it reaches its destination.
The union specifically referenced an incident earlier this year, when about 30 non-essential crew had to be flown off the vessel after a fire broke out on-board.
It was announced last month that Unite members on the vessel would down tools as part of a dispute over redundancy packages.
According to the union, workers have been offered a “significantly inferior” deal compared with Altera employees onshore.
Dozens of workers, who will be made redundant at the end of August, will engage in continuous strikes from Friday.
Foinaven is due to leave the namesake BP (LON: BP) oilfield – about 120 miles west of Shetland – tomorrow headed for Hunterston Port.
It is expected to arrive early next week.
Vic Fraser, Unite industrial officer, said: “Unite has repeatedly sought assurances that Altera are clear on the actions that our members will be taking during the strike, and the effect this has on the Foinaven during tow.
“We have asked Altera if they have contacted its client BP, the towing company Maersk, and all the regulators to ensure that they are also fully aware of the implications due to the strike action.
“We remain deeply concerned for the safety of the crew during the tow which is likely to involve around 50 people, for the Foinaven itself, the towing vessels and the wider environment should anything go wrong.
“Quite literally our members could be stranded at sea for days without any clear safety procedures in place. To date we have faced a wall of silence from Altera over these real concerns which is unacceptable and dangerous.”
Around 60 workers, employed in a variety of roles, such as crane operators, electricians, deck crew and production technicians, are involved in the industrial action.
Unite confirmed in July that 96% of its members on Foinaven, which is owned by Teekay, had backed downing tools on an 84% turnout.
A decision was taken to retire the vessel after a string of health and safety issues cropped up, including a crack in its hull.
BP handed in a decommissioning plan for the FPSO in January, and the contract for Foinaven will wrap up when it leaves the West of Shetland field, the future of which is still under consideration.
It is still unknown where the vessel will ultimately end up, and there are fears it could be broken up overseas, meaning the UK would miss out on decommissioning jobs.
Teekay has already found an undisclosed buyer for the aged FPSO.
A spokesperson for BP said: “Safety is always bp’s first priority. We continue to work closely with Altera and are satisfied with the plans in place for the safe removal of the Petrojarl Foinaven FPSO.”
In a separate statement, Altera said: “Altera Infrastructure, as operator of the Foinaven FPSO, remains committed to the safe demobilisation of the vessel. Safety remains the absolute priority and the towing operation requires to be conducted within a timeframe that reflects this.
“It is important that we take advantage of favourable weather and operational conditions to this end. At no time has the operation been rushed, and will only proceed with the endorsement of BP, other interested parties, the technical team and the UK authorities. As with any offshore operation, full contingency plans are in place to address any challenges which may arise.
“We remain committed to bringing Foinaven safely back to port after her many years of service in the North Sea and we have absolute confidence that we have all the necessary requirements in place to ensure a safe and compliant tow.”
Maersk and Teekay have also been approached for comment.
Foinaven was the first field west of Shetland to begin production, in 1997, and could still hold some 200 million barrels.