Exploring hydro power station and its mysterious appeal to ladybirds

Updated

Some people are attracted by power and on the west coast of Tasmania it seems a certain pretty insect is too.

Ladybirds, in their tens or hundreds of thousands, flock to the John Butters Power Station, south of Queenstown every spring.

Sometimes a couple of bin-sized garbage bags can be filled with the dead bugs.

Nobody seems completely sure why the tiny insects are so interested in being inside a concrete power-station with noise levels constantly around 85 to 100 decibels.

Hydro Tasmania's west coast production manager Jamie Young started overseeing the John Butters Power Station a couple of years ago.

When he was first told about the ladybirds' infatuation with the place, he thought it was just west coast humour.

"The first year I reckon we got three or four big garbage bags full of them, just off the floor," Mr Young said.

"I'm not sure if it's the magnetic field — that they're attracted to it, or the colours or whatever it is.

"We actually got the university involved but they haven't been able to say 'this is the reason why they're coming'."

Dr Cathy Byrne, senior curator of invertebrate technology at the Tasmanian Museum and Art Gallery (TMAG), told ABC Local Radio that not much was known about the phenomenon.

"There's been a little bit of work done in Tasmania but no one's come up with any really definitive answers," she said.

"What we know is that ladybirds definitely aggregate.

"It's influenced by a few things and one is prevailing climatic conditions, so often over winter, also in our spring.

"We mostly see it with Cleobora mellyi, or Tasmanian ladybird and also the common spotted ladybird (Harmonia conformus).

"A colleague at Forestry said there was a shed at Ridgeley where ladybirds used to aggregate every year and when they relocated the shed, the ladybirds still went there."

During the 2014 Queenstown Festival [now the Unconformity Festival], Hobart installation artist Dean Chatwin found thousands of dead ladybirds in one of the abandoned houses at the Lake Margaret power station.

He used the bugs to create a dozen densely-packed semicircles on the floor, assuming the configuration of a hydro-power-generating pelton wheel.

Mr Young's association with the John Butters Station goes back to working on construction phase of the King River scheme in the late 1980s.

Standing on an elevated metal platform attached to the power station, Mr Young gestures at the impressive flow of the King River snaking off to the south through thick rainforest.

"We have an outflow of roughly 100 cubic metres of water per second. You can't see too much upriver but people often walk up here to fish," Mr Young said.

"This is my second year in this role on the west coast but I was here 34 years ago on the construction.

"This was one of the last stations to be built; Tribute power station towards Tullah was the last one."

Even before heading indoors, the huge scale and inherent energy of power stations is already evident in the form of a six-metre high concrete tunnel used to access and maintain the penstock, which feeds water into the power station.

The penstock is half a kilometre long and fed by another 6.5km of tunnels from Lake Burbury, all underground and under the slopes of Mt Juckes.

The Crotty Dam is one of the highest in the state though not as wide as Lake Gordon. It is built in the spectacular King River Gorge, which cuts between Mt Juckes and Mt Huxley.

"Standing on the Crotty Dam, I've always wanted to walk the Gorge. Apparently there's gold in there too," Mr Young said.

Once inside the John Butters station, there is no time wasted in applying hearing protection.

On the upper floor the noise is around 85 to 90 decibels; 30 metres down on the lowest level, it is around 100 decibels — not too far below the level of a rock concert.

At that lower level a huge, single shaft turbine spins within bearings big enough to climb into.

"What we're looking at over there is the busbar chamber," Mr Young explained, straining over the noise.

"We have three phase busbars. Comes out of the machine at 13,800 volts, goes up to a transformer that converts it to 220,000 volts.

"In domestic terms, it's enough power for Queenstown, Zeehan, Strahan and Tullah.

"It then goes into a trans line and over to Farrell sub-station near Tullah and can be distributed to anywhere in the state from there — wherever the need is."

Visually, the most striking element of the John Butters Station is the operating or exciter floor.

This is where the brutalist concrete charm of a hydro power station is subtly adorned with unique electronic cabinets, switches and gauges.

It all looks like it was borrowed from the set of a sixties sci-fi film.

This is where operators can actually assume manual control of the power station when required, but Mr Young agrees it does look faintly like a disco on the flight deck of a space-ship.

"If we actually had disco balls and some lights, it would be just like that for sure," he said with a laugh.

The local residents — the ladybirds at least — clearly would not have a problem with the noise.

Topics: science-and-technology, hydro-energy, energy, animal-science, invertebrates---insects-and-arachnids, contemporary-art, queenstown-7467

First posted