User:Vincecate/WaterWalker2

Looking at building a 1:5 scale model/prototype like the WaterWalker model that is big enough for 2 people to take a kite powered ride along the South side of Anguilla. The legs will be 20 feet long. I have done several seastead models but this will be the first large enough to play on.

Got these 3 barrels for $20 each from the concrete plant.

This 3" by 3" square tube is 20 feet long and cost me $53. Tropical island prices include shipping and duty, so are usually nearly twice mainland prices. I just got one so far to make sure I can work with the ends and that it is strong enough.

Testing 20 foot steel box-beam (square tubing) with 250 lbs on it.

Testing 16 foot 4x4 with nearly 300 lbs on it. The extra weight came on of its own accord.

Weights

• Barrels 20 lbs
• 3" square tube 20 feet long - 48 lbs
• 4x4 at 16 feet long - 60 lbs

Flotation

They are 54 gallons which is 432 lbs in fresh water and a bit more in salt water. The plastic should displace enough additional to float the 20 lbs of the barrel, so we can ignore that. The ropes around the tripod base will also be underwater so their net is nearly zero as well and can be ignored.

• Total flotation 1296 lbs
• Using half each 648 lbs
• Weight of beams 144 lbs
• Available for people and other 504 lbs

Wood beams weigh more, but the weight of the part that is underwater does not count, and will actually give some net buoyancy. So wood could work about as well really. It might be possible to close off the end of the steel tube so no water could enter and it would provide some buoyancy, but I don't see it. If we had an aluminum box beam that was thick enough to weld to we could close off the end and make something to attach to at the same time. A 6 inch square aluminum box beam would be great.

There is a guy that makes handrails on this island out of aluminum pipe. If I could get a long piece of that it could be very good. Will try.

Possible Things to work on next for this project

• Measure force/speed for barrel in pool - barrel half full of water - both on side and upright
• Measure force/speed for 4x4 section in pool
• Put piece of 4x4 into ends of box beam
• Figure out how 3/4 beams will join together at the top
• Figure out if I want to suspend a kayak as the seating and backup or other type of seating
• Measure thrust lbs from Hobie Outback
• Measure force from kite
• Make attachment to barrels and test by filling barrel with water and lifting by rope
• Top connection can be by elastic cord and weight of people pulling 3/4 beams together
• Model 4 leg WaterWalker to see how reasonable that would be - diagonal ropes in air or full tensegrity?
• I have pulled my 2500 lb boat with my kayak, this at 1/10th the weight but less hydrodynamic is probably similar really, so maybe don't bother with measuring things ahead of time.