Tuesday, 29 November 2016

Wind Pump

You don't see many wind pumps like ours in the UK, probably because we get so much rain that we don't need them and also because they only work when the wind blows.

We have all seen them in cowboy films and horror movies. A film company once enquired about filming a murder in our Great Meadow because they needed a pump in the background. They certainly add some atmosphere, especially when  they are the only upright object for miles in a flat landscape, and the more battered they are, the better they look. Then there is the creepy creaking sound that they make when the wheel is turning and the piston in the shaft is going up and down.

Pumps are a common feature of stock farms in arid places like Kansas, Texas and the Australian Outback where livestock may have no access to natural surface water. Think of the farm in the Wizard of Oz for example. Wind provides free energy to reliably bring water up from underground to fill tanks, ponds and troughs and the pumps need very little maintenance to do it. Apart from requiring a little wind, their only drawback is that they are not very powerful and so, if the water is more than a few meters below the surface, they can't suck it up.

Our pump was made in Axminster and came with a thick manual and instructive DVD, but I learned a huge amount about them from a novel by Annie Proulx. You may know her from her gritty books that have been made into films, especially "The Shipping News" and "Brokeback Mountain." She is fascinated by strange men who are outsiders in unfamiliar places, mostly in some wilderness or other.

"That Old Ace in the Hole" is set in the Texas Panhandle where ranchers rely on a shrinking aquifer that lies deep underground. The old creaking wind pumps have largely become obsolete as the water table has fallen, but they still stand rusting in the fields. The landscape is flat, parched and almost uninhabited so that straggling barbed wire fences and rotting pumps are the only things to draw the eye until a buzzard or an owl appears. Great horned owls often collide with the rotors and destroy the mechanism.

Old pumps are peppered with gunshot holes in the tail and the blades, I suppose because there's nothing else to shoot at, except perhaps hog farmers who pollute the aquifer and take more than their share of the water. And that's the main thread of the story.

The old-time cowboys would ride the range on horseback, carrying a bundle of wooden poles. Those old pumps did not turn themselves off when the wind blew too hard or the mechanism jammed, so part of the pump-rod was made of wood that would fail and be easily replaced. If one pump had failed, you could expect all the other pumps in the area to have failed too, so it was a constant job that the cowboys got to hate.

You can't work on a pump if the rotor is turning, so you have to able to disengage the gear box or block the blades in some way. A lasso could be handy (but dangerous) and there are hidden dangers too, lightning strikes being the most common. Most surprisingly for me there is also the danger of electric shock that has nothing to do with lightning. A cowboy might ride up to the pump and reach towards it only to be thrown to the ground by a massive charge of static. The static could be caused internally by friction between parts, but Proulx points out that driving hail can create a huge amount of energy that the metalwork can store like a battery.

Knowing all this, we approach our pump with caution. Ranger Matt Hall and I have chosen a windless day to check that it is working and to find out why the number on the water-meter hasn't changed in a month. (It's the blue bit at the bottom of the tower.) We have to remove the meter to check it as it's not good idea to stick your hand or anything else up the pipe. After undoing a dozen large nuts, we have the heavy meter in our hands and find that it does turn, but it's too stiff. A bit of manipulation by Matt seems to have cured the problem. Now the blades turn when he blows on them,  just like those children's windmills that you used to stick in your sand-castle on a seaside holiday.

While we put it all back together. our herd of highland cows has lost interest in us and they are all lying down to chew the cud, except the black one who is the matriarch and doesn't trust anybody. The pump draws water from an old well and keeps the ditches full enough to water the cattle and and provide a bit of habitat for plants like flowering rush, for frogs and toads and perhaps water voles. Matt has heard a characteristic "plop" on previous visits but we don't see any evidence of them today, neither do we see any water birds, except moorhens. We often find snipes, jack snipes and green sandpipers along the ditches in winter, all attracted because of the work the pump does for us.

It seems strange that we have to meter our water and pay for it. The water comes from our own well and is discharged onto the surface so that most of it soaks back into the ground. But, as Annie Proulx points out, its not just our water, is it?