User:Vincecate/KiteAndSeaAnchor

There are at least two companies making kites to pull ships:

* skysails
* kiteship

With a two rope kite you can have it pull you to the left or right of downwind by maybe 75 degrees. So you can use it to pull you in the direction you want if you are mostly moving in the direction of the wind as you might with a migration. A computer can control the kite. By adjusting where it is in the sky and if it is moving back and forth the computer can control how much it pulls and what the average direction of pull is.

A sea anchor can slow down a seastead. With no kite, the wind on a Tension Circle House might push it faster than a Pipe Spar with a kite. So for a group of different seasteads to travel together sea anchors would be good to have. Also, some seasteads would need sea anchors to go slow enough for an annual migration.

A fleet of seasteads with kites and sea anchors would need their computers to be able to communicate so the whole fleet could move in formation without bumping into each other.

Force from kite

Skysails says their different kites provide around 8, 16, or 32 tons of force in the direction of movement for their rating conditions. Their rating conditions are 25 knots wind, 10 knots movement, and wind at 130 degrees. We are probably more like 16 knots wind and 1 knots movment, but that should be about the same force.

Scale model testing

The force on a scale model should scale with the mass, which is with the cube of the scaling factor. So for a 1/25th scale model, the force should be 1/15625. So we have:

 * 8 ton kite -->  1 lb
 * 16 ton kite --> 2 lbs
 * 32 ton kite --> 4 lbs

Weights from a weight set or a gallon jug filled with the right amount of water could be a good weight. With a known weight being pulled down by gravity you can provide the same force to the model by connecting a rope between the model and the weight over a pulley. Just have to keep pulling the pulley forward at the right speed so that the weight stays between the pulley and the ground or water. With my Hobie pedal powered kayak I think this will be easy enough.

With speed results from this we can see how fast such a kite could pull a full sized seastead.

Power generation

There is a some angle, maybe 40 degrees above horizon, and swooping back and forth in a figure-8 that gives the optimal pull. When they want to winch in a kite they keep in rather still almost directly above so it does not pull so much. It would be possible to generate power with the kite going out at the optimal pull conditions and using much less power to winch it in at the optimal winching conditions. Given the large forces this should be substantial.

You would sacrifice some of your speed potential because when you are winching in the kite is not pulling so much. But this can all be worked out with the proper sizing of the kite.