I had lived in Cragg Vale for about two years in a partially successful attempt at living the self-sufficient life.
One evening in the pub I got talking with Mike, the then owner of the Paper Mill cottage(s). He said that he would like to reinstate the water wheel that was used (many years before) to power the mill. Without hesitating, I said I would do it for him, and we agreed a working arrangement.
The wheel pit was large and I assumed some 10 to 15 feet deep. Clearing it out was hard work and a bit of a surprise because it contained the remains of literally hundreds of chickens. Their burial there was never explained. Of course the old wheel was long gone but I could tell that it must have been about 12 feet in diameter since I could see where it had been sited.
Before this point however, I had realised that I didn't exactly understand how an overshot water wheel worked. I knew that the water enters the wheel at the top and fills a series of buckets set on the wheel, thus allowing gravity to drive it round. But what was the relationship between the speed of rotation of the wheel, the incoming water flow, and the output of useful work?
I decided to build a table model to find out. I made it quantitative and tested it at the kitchen sink. The key understanding was that an imposed load was necessary in order to slow down the wheel enough for each bucket to fill (about ¾ full actually) and thus extract useful work. I reckoned on about 10-15 rpm – any faster would be less efficient. I had assumed that, as with other prime movers, the faster the better, but not so with an overshot wheel!
I consulted the local water and electricity boards, and amazingly they both sent a representative to see me. Both were intrigued by the project and the upshot was that there would be a small charge for the use of the water, because the arrangement would take water out of the watercourse and then return it. (Undershot wheels wouldn't have to pay anything, but my costs were about one tenth of those of a unit of grid electricity). But there was no problem about generating electricity for domestic use, provided an isolating transformer was fitted an any point where the domestic wiring connected with the National grid.
Being a joiner, I naturally designed the wheel mainly in timber, only the main shaft and its bearings being (of course) of metal. I made a careful sketch of the whole set up. It took about two months to build (I was working on my own), and I vividly remember being constantly harassed by Mike's cockerel and ducks, and also a couple of days when I couldn't work, because of a plague of ladybirds!
It was towards the end of the very long, very dry, very hot Summer of 1976, and the ladybirds were in such huge numbers that you couldn't walk anywhere outdoors with stepping on as many as could fit under your boot – really quite creepy!
The wheel itself, as photographs show, got finished all right, but unfortunately Mike ran out of money at that point, so we never got round to the next stage, which would have been gearing the thing up to about 1500 rpm and attaching a generator. The intention had been to provide heating and lighting for his (newly built) duck shed, but alas 'twas not to be.
It was a really beautiful late summer's evening, I was standing on the bridge above the wheel pit, and Mike was down in the pit beside the wheel. I said, "Shall we?" and he nodded, so I opened the sluice gate fairly full – I was determined that the wheel should turn (for the first time under water power). In no time, it was doing 50 or so rpm and I had to shut it down quickly before it destroyed itself! It turned out that a mere trickle, say as from a water tap, was quite enough to get it turning at about 10 rpm, thus reinforcing the discoveries I had made with the model.
So, overall the project was a mixed bag: I really enjoyed all the building work, and seeing the wheel turn under natural power, but it was a sadness that it never produced any useful output; not too long after that I moved down to London where I have lived ever since. It was, of course, a really minuscule slice of local history, but I hope it has been of some interest to at least a few people.
About 10 years later, I was in the area for a holiday and couldn't resist dropping in on the wheel. The wheel was (of course) still there, so I knocked on the door of the cottage. The new owner was a charming lady and she asked us in for a cup of tea. Believe it or not, from the mantelpiece she drew a piece of paper – it was my original drawing of the wheel and site from all that time ago!
Revised 20:07 /24th February 2020 / m_39 / 6651
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