The Windmill - by Ted Lee
Note this article was written for this site by my friend Ted Lee who has sadly passed.
Wind is free but you don't get nuttin for nuttin Windmills are delightful things, they screech and rattle, day and night, day in day out, so long as there is wind. The little outback town of Springsure used to have a windmill in every house yard, you can imagine the tune on a windy night. Windmills are used for a variety of things, the best known in Australia is for pumping water, but some charge batteries.
There are a huge range of sizes with wheels from 8 to 30 feet (2.4 to 9.14 meters) in diameter. Standing as tall as 59 feet or 18 meters, capable of pumping up to 10,450 gallons that's 47,440 liters per day from bores as deep as 600 feet or 183 meters. Just stop right there ! Lets think about that a minute. A bore 600 feet deep with a 4.5 inch pipe down it with a 6 inch pump on the end would be lifting 1.2 gallons of water each stroke. If there was 500 feet between the top of the water in the bore and the top of the tank there would be 344.5 gallons of water in the pipe alone weighing 1.53 Imperial tons, (not counting the weight of the pump rods) this is all hanging on the mill the moment the up stroke begins. ( the power of the wind)
Occasionally the bucket in the pump needs replacing, all the pipe and rods have to be pulled up, each 6 meter length unscrewed and put to one side as they come up. Two brothers used to travel around the district ( Central Highlands Queensland ) doing this work, their FC Holden Ute loaded down with tools, spares and accumulated bits and pieces. They used the old-style pulley-blocks and rope coupled to the Ute to pull up the pump. With up to 1.5 tons of water plus the pipes and rods up to another 1.5 tons, no wonder the poor old Holden had 3 gear boxes. (one in use, one spare and one away being repaired.) Their complaint was "Reverse gear don't seem to last very long."
This mill that I was involved with stood about 45 ft (14 mt) high with a wheel of 21 feet (6.5 mt) and pumped water from a bore 360 feet deep (110 meters). It was the last windmill in the district to be backed up by a steam engine. ( The steam engine was a very old overcrank one which stood on 4 ornate posts, and would be a valuable historical item today. The boiler (Shame on me) I cut a Dozer blade out of it, but what a job the metal was all separated into sheets and the Oxy couldn't cut cleanly through it.) Not long after Diesel power took over a slipping cotton / rubber belt caught fire and burned the engine shed down, damaging the engine.
Windmills can Breakdown
It had at one stage run low on oil, the white-metal big-end bearing had gone. My brother replaced the connecting rod with two pieces of hardwood bolted together either side of the crank-pin. This lasted a couple of years, in the meantime the pull rod swivel pipe wore through. This rod is about 8 meters long, is made from 1 1/2 inch ID pipe with a collar at the top and a thread at the bottom. It passes down through the center of the head and tower, connects to the pump rods and allows the mill to swing around 360 degrees without twisting everything up. A chain passes up through this pipe connecting to the mechanism that allows the mill to be turned out of the wind, to stop it pumping. This chain had worn through the thread and allowed the pump rods to drop off.
The local Plumber came out for a visit and we talked him into coming out to look at the mill. We climbed up the mill, disconnected the chain and pulled it up through the pipe, then pulled the pipe up out of the top of the mill and threw it down to the ground. The replacement part that we had was the wrong one, what do we do now ? Simple, I poked the pipe under my 48 Vauxhall tourer and tied it up to the front and back bumper bars with fencing wire, (our Plumber had never seen anyone carry an 8 meter pipe under a 4 meter car before) then off we went 8 miles into town to get a new thread welded onto it. This put the mill back in service.
Remove the Wheel
It used to groan and shudder as it stopped turning when the wind died down. Although the wooden connecting rod dipped into the oil OK it wasn't shaped to carry oil to the main bearings so they went dry. The crank pin was badly worn and had cut into the wood, it was decided to do a proper repair.
Easy, just get a new connecting rod and a new crank, err well careful now, how do you propose to remove the old crank ? The crank was press fitted and keyed to a 3 inch diameter shaft about 4 feet long with a 21 foot wheel on the other end and 45 feet from the ground. Our friendly plumber was the local Southern Cross agent so he ordered the parts and supplied a man to help with the job. This man was so scared of heights that he clung to the top of the tower with both hands and tried to undo bolts with his teeth. I wasn't much better, but I did manage to climb out onto the tail and attach a rope which we tied to a tree to stop the mill from swinging around.
The tail was made from 3 X 8 foot sheets of corrugated iron attached to a 20 foot length of 4 inch ID galvanised pipe and a stay rod. My Plumber friend said it was just as easy to walk along a 4 inch pipe 45 feet from the ground as it was to walk along it on the ground, that was alright for him to say, it was me who who had to prove him right !!!!! We mounted a Gib Pole at the top of the tower with a snatch-block at the top, with a wire rope attached to a tractor to lower the bits as they came off. The wheel begins with a hub, 8 spokes or frames 10 feet long held by 4 bolts each = 32 bolts. 2 outer rings with 2 bolts each at each spoke = 32 bolts. 2 inner rings with 2 bolts each at each spoke = 32 bolts. OK so far ? There were 24 fan blades with 4 bolts each to attach them to the rings = 96 bolts that's 192 bolts all up, all had to be undone one at a time and put in a leather bag around ones waist, (don`t drop any, the guy down below might not appreciate it ).
Besides we will need them all later. We started at the bottom and began removing the blades, this put the wheel out of balance so we let it rotate around and removed some more from the bottom again. Then we had to turn the wheel with a rope and pulleys until we removed all the blades. Next the rings then finally the spokes, all the pieces had to be lowered to the ground as they came off as there was nowhere to store them on the tower. Then came the heavy parts, the main bearing was a piece of cast iron about 2 feet long bolted over white-metal bearings. We needed the old "Fergy" to lift and lower this part and the shaft, complete with the hub and crank. We took the shaft back to town and they fitted the new crank over night. So next morning we were all ready to put everything back together.
First thing was to re-fit the shaft, we had to stand on top of the mill-head and man-handle it into place as a third man lowered it down with the Fergy. I don't know if there is a right and a wrong way to build up a windmill wheel but the moment we fitted the first spoke we realized that we couldn't rock it back and forth like we did taking it apart. We finally got the spokes and rings all assembled. (tips n trix Bolts, remember put all the bolts in first, then tighten them up) Now for the blades, we found ourselves half way around the wheel (in the wheel) working away from each other to keep the balance, (we hadn't even noticed that we were doing that) not bad for a couple of blokes who only yesterday couldn't move without hanging on with both hands.
A few days later I went back to see how the mill was going. Watching the connecting rod and crank dipping into the oil, I noticed that the oil dripping off the crank missed the channel that carried it to the main bearings. I studied this for a while then put a piece of tin with a twist in it, under the head of the bolt that held the con rod locating washer in place. The oil pored into the channel.
The property owned a square mile (640 acres) of land Islanded by neighboring properties, i.e. the only access was through other peoples properties. There was a brand new dam built on this land besides another watering point, a mill & tank. There had been a considerable amount of rain and it was impossible to reach this land to see how things were going. The owner was anxious to see the new dam etc. so we fitted the "carry all" to the Fergy one afternoon and set out through the black mud. The dam was full to overflowing, any cattle that we saw were fat and healthy, there was plenty of water and grass. We continued on to the other corner of the paddock, but as soon as we caught sight of the mill we knew there was something very wrong.
This mill was a small geared one (the 10 foot wheel does about 3 revolutions to one cycle of the pump.) It's tail was up in the air and there were fan blades laying all around on the ground. Of the 12 bolts that held the head onto the tower there were only two left in place, whenever the wind changed the head would rock over on these bolts and the wheel would crash into the tower. We determined that we could salvage it if we acted quickly. We gathered up the fan blades, the ones still on the wheel were undone with the fingers to save them, and loaded them onto the Fergy.
Seven new blades were ordered the rest were salvageable. Now we must call into question the ordering system for spare parts for windmills, this is the second time the wrong parts were supplied. This time it was easy enough to cut 6 inches off the larger end and re-drill some of the holes. So armed with a set of fan blades, a stack of new bolts with spring washers (I don't think the windmill people had ever heard of spring washers,) and some tools we ploughed the old Fergy through the mud again. First on the list was to secure the head upon the tower. Using a Genuine American "Power-Pull" ratchet winch we pulled the tail down carefully, then as the first bolt holes began to line up I drove a podgee bar in, and began to breathe easier. Soon we had all 12 new bolts in place and tightened up.
Re-building the wheel was much easier than the big one, even so we spent the whole day working on that mill, (the feet ached from standing so long on small round bars.) We went over all the bolts in the tower, even the ladder was loose. One loose bolt can lead to the total collapse of the mill given time, every time the wind changes the weight shifts on the tower and it will work away at that loose bolt until another one moves and so on.
Mill number 3
This mill again a small geared mill of 8 or 10 feet, it pumped water from a small dam to a "Turkey Nest" (a hollow mound of dirt lined with clay, a common substitute for a tank, would hold 30 or 40 thousand gallons of water,) this was then connected to a cattle trough. Due to the lack of wind ( common in the Central Highlands winters ) the Turkey Nest was running low and there was no back-up pump. A portable Villiers / Finsbury Fire Fighter was sometimes used but it would only run a couple of hours on a tank of fuel. The other alternative was to move the cattle out of that paddock. (not very helpful)
I sat on the Turkey Nest and watched, a gust of wind would come up, the mill would slowly begin to turn then the gust of wind would be gone, about 1 1/2 cups full of water would trickle into the turkey nest. I thought about that ( my work mates often ask "Do you sleep at night?" you think about these problems in your sleep and wake in the morning with the answer.) There was about 20 meters of 38mm ID Poly pipe between the dam and the mill with a suction lift of about 3 meters and about the same head lift and distance to the turkey nest tank. That works out at about 180 liters or 180 kilograms of water which the mill had to get moving during that gust of wind.
I lost you back at the last gust of wind didn't I ? The answer was simple, hunting around the shed I found a length of pipe and some fittings, tees etc. I cut the pipe in half and welded a plate over the cut ends. I fitted a tee either side of the pump then screwed the pipe pieces into them with the welded ends up inside the mill. The next time I visited that mill the "Turkey Nest" was flowing over. After pumping for a little while the pieces of welded pipe would set up a balance, vacuum in one and pressure in the other, then when a gust of wind came the mill would spin over drawing water from one pipe and pushing it into the other, the increased vacuum and pressure would get the water moving between the dam and the "Turkey Nest" during the mills idle stroke. So the mill would spin over 2 or 3 times at each small gust of wind instead of stalling against the load, pump 5 or 6 liters of water instead of just 1.5 cups. The air bells on the Rosebery Pumper performed a different function, to soften `water hammer' caused by the sudden stop and start of the column of water. Windmills, like any other machine, do need some maintenance, every once in a while top up the oil in the head, and check the bolts for tight.
Ted seems to be writing more for S&E than I am lately - I guess I will have to pull my finger out and catch up!
The windmill photo had a note on the back of it "This mill situated at the Longreach Stockman Hall of Fame is much larger than the one in the story, it is typical of our Central Australian Icon. At 10 years of age, my son climbed up this mill to the platform & I had to go up to make sure he could get down OK. Last year (1999) I couldn't help but take this photo."
Just for interests sake, windmills like the ones in Ted's photo are found all over Australia, I have often thought about building one in my yard.