They were designed to withstand cyclones but yesterday’s blustery conditions were enough to wreck two wind power turbines on top of the Marine Board Building.
The turbines were seen spinning out of control in winds of up to 54km/h just before midday – before two blades came loose and fell in on themselves.
For the second time in a week, police closed part of the city to cars and pedestrians.
The company that operates the turbines, I Want Energy, gave assurances yesterday they were not dangerous.
Director Rob Manson said a safety mechanism prevented any piece of the turbines from coming off the building.
He said yesterday’s problem was caused by excessive wind and a possible failure of the electric braking system.
“The safety mechanism kicked in and worked exactly as it should have, causing the blades to fold in on themselves,” he said.
“There was never any danger of them flying off the building or anything like that.”
But witnesses who watched the drama unfold from a nearby building said the situation looked anything but safe.
Phillip Groom and his colleagues noticed the turbines appeared to be spinning out of control.
“It looked dangerous to me,” Mr Groom said.
“The one that really concerned us was on the south-west corner of the building.
“It was spinning at a thousand miles an hour but it was bent to one side and was wobbling from side to side.
“We were scared because we could see people walking on the street below and it looked like the whole assembly might fall right off the building.”
Mr Groom said one of his workmates called police and the turbines were stopped within 15 minutes.
Mr Manson said the turbines were designed to withstand cyclonic wind of 60m/sec or 216km/h and should have withstood yesterday’s conditions.
Investigations are under way into what caused the problem.
Police Inspector Glen Woolley said: “We closed off roads around the building to cars and pedestrians.
“Because of the nature of the situation, we weren’t prepared to take any chances.”
Insp Woolley said police were getting well practised at closing off part of the city, referring to Monday’s bomb scare in Liverpool St, but he did not believe they were over-reacting.
“The safety of the public is paramount,” he said.
Hobart City Council alderman Peter Sexton said the incident raised legal concerns because any future accident would be considered foreseeable and the State Government should instigate some form of inquiry.
He said the wind speed was only a quarter of what the turbines were meant to be tested to withstand.
“This now means liability of not only the building owner but also the State Government and the Sullivans Cove Waterfront Authority,” he said.
Ald Darlene Haigh, who opposed the turbines from the beginning, said she now felt her concerns were vindicated.
“It is my strong belief, considering what has happened, that wind turbines should never be constructed and operated where there is any possibility of people being harmed by the loss of a blade,” she said.
Lord Mayor Rob Valentine said the over-riding issue was safety and there must be sufficient safeguards, as with any equipment on any building.
The loud noise of the turbines crumbling drew city workers out of their buildings.
Council worker David Beaver said he heard a loud crashing sound and joked that it may be a turbine falling down.
“I couldn’t believe it when I went outside and saw it had actually happened,” he said.
“This shows they are obviously unsafe. It is inappropriate for these things to be on a roof in the city if they are not properly secure.”
Fellow council worker Piangpen Narksut said: “They were spinning like crazy.
“It is a pity this has happened because we need sustainable energy and they were serving a good purpose.
“But it isn’t really that windy today, so they obviously need to be properly secured.”
|Wind Watch relies entirely
on User Funding