Previously
It’s been a few years since we told you about Eddie Firth showing us an old Pelton wheel (a type of water turbine) – you can read that here. It came from the Devon Mine on the Dove River. But it might have started its life at the copper mine owned by the notorious Barn Bluff Gold, Copper and Silver Mining Company (Barn Bluff Company). The research we did at the time couldn’t prove it one way or the other. We promised that we’d look into it again.
Eddie worked out another way to answer the question. We would compare the spacing of the bearing mounting bolts on the Devon wheel to the bolt holes on the frame that supported the Pelton wheel at the Barn Bluff Company’s mine.
In the meantime
Before revisiting the mine, we’d solved a lingering doubt about the Barn Bluff Company’s Pelton wheel. In 1901, the mine’s owners said that they had ordered two 4 foot (1.2m) diameter Pelton wheels.2 However, the Devon wheel was 2 ½ feet (0.76m) in diameter. Previously we’d thought that the mine owners had lied about the size of the Barn Bluff wheel. They were well-known for exaggerating almost everything else about the mine.3 They had lied.
In 1902, a mines inspector visited the Barn Bluff Company’s mine site. He reported that there was one Pelton wheel and it was 2 feet (0.6m) in diameter.4 The 6 inch (150mm) difference between it and the Devon wheel could be due to the way the wheel was measured, maybe.5
Now we could focus on whether the tell-tale pattern and size of the bolts of the Devon wheel and the holes in the Barn Bluff Company’s frame matched.
Making sense of the machinery site
Eddie, Jenny and I closely examined the area of the mine and recorded the significant features. Then we made some educated guesses to untangle the clues and make sense of the place so that we could find the Pelton wheel frame.
We found that water was channelled along a race high up on the southern side of the valley of Commonwealth Creek. The water race ended abruptly in a forest. However, we located a long narrow clearing running steeply down to the creek. It would have been cleared for a long iron pipeline, the penstock, that fed the water to the machinery. We even found a few rusted remnant lengths of the riveted pipe at the machinery site.
At the base of the penstock we located the machinery site. It had been cut into the northern bank of Commonwealth Creek. It was everything that you’d expect from a mine abandoned more than 120 years ago. All the equipment was gone. The forest had come back. What remained was a few unusual lumps and bumps under a thick carpet of leaf litter.
Nearest the creek were two long narrow slabs of concrete with a shallow timber-lined channel between them. This must have been the foundations for the Pelton wheel. They would have held the frame that we were looking for. A squared log lay over one of the concrete slabs. Was it part of the frame and were there any more pieces?
Following the alignment of the Pelton wheel foundations brought us to a stack of thick squared logs in a niche in the side of the hill, the site of the horizontal air compressor and its concrete foundation.6
There were also a few rotted timbers that were possibly the last remains of a shed that covered the compressor and a blacksmith’s shop. Nearby were two short solid logs that would have held an air receiver tank.7
Solved? – the bolt spacings on the frame compared to the Devon wheel.
We were looking for the frame. It should have looked like the sketch at the start of this blog and the plan shown here. The frame would have been made of squared timbers that were bolted together. We were most interested in the three beams at the top that held the wheel. They would have the tell-tale group of four bolt holes for the bearing housings. These timbers were probably 4 inches (100mm) wide and 3 inches (75mm) thick.8
We had found one squared beam lying across one of the Pelton wheel’s concrete foundations. Part of the frame? It wasn’t. It didn’t have any bolt holes. Indeed the bolts in the wheel foundations had been bent out of the way. It also had odd shapes cut into it. Because of this and its size, it was probably a compressor bed log that had dragged there when the compressor was removed.
Unfortunately, there was nothing at the site that would have been part of the Pelton wheel frame. We had hit a dead end.
It was likely that the frame was supplied with the Pelton wheel and went with it when it went to its new location. The frame would have been bolted together so that it could be easily dissembled and reassembled, as it would have been when it was originally moved to the Barn Bluff Company’s mine.
The conclusion
After all this time and effort, we still can’t suggest whether Eddie’s Devon Mine Pelton wheel had operated at Barn Bluff Company’s mine. This is a disappointment, but we don’t solve every search subject.
Because of the lack of material evidence, the frame, we will park this investigation for the time being. But it will sit in the back of our minds waiting for that some piece of information that cracks this case. When we do solve this one, we will you know. To be continued, maybe ….
Copyright Peter Brown 2025
1 Modified layout from Pelton wheel patent, US Patent 409,865: Water Wheel by Lester Pelton, 27 August 1889, US Patent and Trademark Office
2 Advertiser, 1 June 1901.
3 Mount Lyell Standard and Strahan Gazette, 4 March 1901.
4 Report of the Secretary Mines 1902-1903, Mineral Resources Tasmania, AR1902_03, page 79
5 The diameter of a Pelton wheel is normally measured to the outside of the cups. If the Devon wheel was measured to the inside of the cups (the width of the wheel) it would be 2 feet.
6 A manager’s report stated ‘Since my last report bed logs have been squared and embedded in cement, and securely bolted together; air compressor fixed on to same, and main shaft placed in position’, Daily Telegraph, 5 December 1902.
7 Manager’s report, ‘Since my last report have erected machinery shed, with blacksmith’s shop attached’, Daily Telegraph, 13 December 1902.
8 The width of the bearing housings are 4 inches (100mm) and the rusted bolts had a 3 inch (75mm) space between the bearings and their heads.