Islands Council has decided to go ahead with buying the £7.6 million tug currently being leased at Sella Ness.
The purchase of the Dutch vessel Multratug 29, which was chartered in April for three years as a replacement for the outgoing Tirrick, is due to go through on 25 October.
Following a recommendation to buy from the harbour board last week, the final decision was taken at Wednesday’s full council meeting in Lerwick.
The council has an option in its contract to purchase the two-year-old tug, which would cost £7.6 million if bought after six months of operation.
A decision to exercise that option had to be made by close of play on Wednesday.
The performance of the tug has been monitored and the “vessel has in most cases exceeded both the specifications and expectations of sea staff”.
Purchasing the tug was deemed to be more cost effective than continuing to charter the vessel for the next three years – which would have cost just over £1 million per annum.
The capital costs of buying the boat will be funded by external borrowing, but harbour fees and charges will recoup the money spent.
Speaking at Wednesday’s meeting, harbour board chairwoman Andrea Manson described last week’s talks on the tug as a “wide-ranging discussion” with “input from the officers, input from the crews and input from the pilots”.
The matter had previously bypassed the harbour board, with North Mainland councillor Alastair Cooper successfully securing an emergency meeting last month when the business case was presented to the policy and resources committee.
“We’re reassured that this is a good vessel, which can do any task which is set for her,” Manson said. “It’s affordable and a sensible buy, therefore I recommend it to you.”
West Side member Theo Smith welcomed the fact that staff who used the tug had been asked to give their thoughts directly to the harbour board.
Lerwick North councillor Stephen Leask said he had been reassured over the cost-effectiveness of buying the tug should towage be put out to tender in the future.
He was encouraged to hear from infrastructure director Maggie Sandison that if the “vessel is going to be in a transfer of tender, it would be taken over by not necessarily the council.”
The motion to buy the tug was moved by Manson, with North Isles councillor Ryan Thomson seconding.
