Saturday, 6 May 2017

Updates etc 060517

Last week I was on a bit of a pulley jag showing some footage whereby you can achieve some mechanical advantage with levers and especially with pulleys. I got a tsk from my pal Russ saying that I shd have mentioned the eSpanish windlass as another way of making things move.  I have mentioned the eSpanish windlass in the context of applying a torniquet to a sheep's leg.  It is a really nifty appropriate technology tool for, say, tightening up a length of fence and Young Bolivar and I used them when building the woodshed last Summer to force the telephone-pole uprights upright.  to .  This is how the thing is made, with diagrams and safety notes.

The same principal is at work with a windlass winch, except instead of the rope shortening by twisting about itself as with the Spanish, the slack of the rope is taken up by being wound around a log.  Another log at right angles applies the necessary leverage. In using this tool it is not necessary to behave like a neanderthal misogynist git who is (marginally) politer to his dog than his wife and various hapless twigs.

But there's more!  Here is a flip-flop winch which allows a single person to set up and use a system with a rope and two stout sticks to shift a heavy object.  Or two stout sticks and a couple of fit young Germans

And then there is a Chinese windlass where the key for leverage is a difference in the circumference of the axle. Never heard of that: very clever the Chinese.

All those solutions to weight moving are temporary examples of bricolage with what is available at hand in the forest.  It you want to make a more permanent capstan with a curious mixture of modern tools and medieval technology check this video out.

Last week one of the links made a comparison with the Man Who Planted Trees. Here is another such story from an island in the Brahmaputra [prev]. The importance of trees in stabilising riverine banks is illustrated in this report on slumping in the levees downstream from Oroville.

1 comment: