|Poor Man's AWECS
AWECS typically rotate at the surface with wind direction. An exception is kite arrays where every individual kite rotates aloft on a short swivel leader.
The Golden Age of Kites in the 19th century saw development of cool turret houses, containing powerful kite winches & miles of piano wire, where operators could monitor & operate protected from weather. These turret houses were typically a "Lazy Susan", a circle of wheels rolling on a circular track. A related earlier solution was the post mill, a small rotating windmill set on a post & moved by hand. Modern heavy duty turrets emerged on military platforms, cranes, draw bridges, & such. Many are potentially suited for AWECS & available as scrap, but the original capital cost of a large machine turret is high.
There are super cheap options. Simply anchor the kite & let the the tether twist as the weather patterns determine. Excess twist is taken out manually during calms. Next in complexity is to add a swivel to the tether, which serves well where twist is frequent. Swivels are a topic in themselves for a future tech note.
Many AWECS have ground equipment to rotate & some sort of carriage is required. On smooth water, an artificial pond even, a moored raft is all that is needed & in chop a boat anchored bow to windward serves. A quick high quality turret is to bury an vehicle axle with one wheel sticking up. Often playground merry-go-rounds have been made this way.
Another simple carriage turret can be made with an axle & wheel. The axle end without the wheel is anchored & the wheel is free to roll in a circle. Equipment can hang as a pendulum mass from the axle or wheel hub. Swivels, bushings, & bearings are incorporated as needed.
A versatile carriage turret is made like a chariot with two wheels on an axle anchored mid-axle. A Y-bridle or yoke from the axle connects the tether & provides the leverage for following wind direction. A house or housing can be mounted on the axle & all of the functions of a full mechanical turret are possible. Boat trailers make ideal turrets of this sort & are abundant as salvage. Simply chain the anchor to the beefed up axle centerpoint & let the tongue be the kite tether lead. A fine winch house can be built on it. Small two wheeled camper trailers could be modified into turret houses. Two-wheel carts anchored by the axle center make fine experimental platforms.
Giant carousels have to be skeletal truss & cable affairs to be economic. Vehicles on a circular track or path allow wide diameter AWECS geometries at lower capital cost, but with dragging hazard. A mobile transport AWECS might be set to steer in a circle as "parked". Earth berm rings or even simple shallow pits allow winch vehicles to park on a slope with great purchase against tug force. The cheap method of large diameter AWECS surface rotation is to belay multi-tethers around an anchor circle.
Anchors have been well covered previously, but its worth noting that the rotation requirement drives optimal anchor design. Soil anchors might be arrayed as a small circle. Dead-man plates & beams buried flush can keep an anchor point fixed. Buried trusses & spaced anchors can underpin track.
FairIP/CoopIP ~Dave Santos June 18, 2010 M1668
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