Water Weight Tower "Foundatiion"

[Phil Timmons]

Did a search and did not find anything like this . . . .

Maybe for a good reason

Has anyone tried using a water weighted foundation for towers?

I am thinking this could be a relatively portable (as long as local water sources are available) tower base, that requires no concrete foundation, anchors nor guys.

The concept is still a bit fuzzy, but say a 8 feet by 8 feet by 4 feet deep "tank" of water weights somewhere north of 15,000 lbs.  Using such a tank as the base of a tower could be pretty stout, but easily moveable by pulling the plug and draining the tank.

Anyway, that is some serious weight on the bottlom of a tower.  If angle braces come up the corners, a tower could be mounted/built up from it, and have some serious side windload resistance, without a foundation or guywires.

I have not done any of the math, yet, but was curious if anyone has seen or read of any designs like that.

Have pondered some simplier versions, too.  We have some water weights (used to hold water or test overhead cranes/hoists)  They hold 250 gallons -- 2000 lbs.  They could be used to "flip-up" a tower and hold it up-right, while full.  To bring the tower down, drain the water, and tower lays back down.  

The only downside that came to my mind was freezing.  Down here (Texas) that did not seem too great a risk, but I follow many of "y'all" are in the Frozen North.  (lucky you -- we had 100 degrees F on the first day of Fall)

Thanks, Phil

[DanG]

Think a new 1,000 gallon concrete septic tank could be adapted as a base?

Water expands 7% turning into ice - some poly tanks for sprayers and ag-livestock are molded to allow some give for freezing but 250 gallons is 33 cubic feet, a 3 by 11 box once foot thick. With that kind of weight, and changing the hinge points makes a catapault you could hurl a piano hundreds of feet with!

How about providing a "quick attach tank" as counter balance to erect tower then through-bolt mast and remove tank? If hard freezing isn't a problem, using four 55-gallon poly drums cast in concrete base to reduce concrete amount would also provide water to raise/lower tower - could be the fail-safe heat dump also.

Just some musings on counter balance mast possibilities...

1 gallon of water equals 8.33 pounds.

one gallon is 231 cubic inches.

cubic foot holds 7.5 gallons.

w/ Cylinder 8 foot long and 18 inches across equals 14 cu foot volume.

14 x 7.5 = 105 (100) gallons = 833 pounds water weight.

w/ Clyinder 8 foot long and 9 inches across equals 3.5 cu foot volume.

3.5 x 7.5 = 26 gallons = 210 pounds water weight.

plus weight of cylinder & frame...

[electrondady1]

   how about an inflatable windmill,  a fold up tower and a water base .

   now you got some real mobility.

[inode buddha]

Not sure if that's a great idea. I used to work for an outfit that makes those. There's not a lot of rebar in them, so the smallest amount of flex cracks them. They actually depend on being buried to keep their shape.

I could see getting one of those skid-mounted plastic tanks from a farm supply, tho and just mount onto the skid frame.

[david anderson]

A couple of things to keep in mind when trying to decide if it will work.

Water behaves differently than a solid weight, and almost any tank you use will have some flex to it. When the upwind side of the tower tries to lift, it will not be lifting that entire weight, it will only shift some water towards the other side of the tank

Fill one of those cheap plastic kids pools, and lift one edge and you will see what I mean.

It will also cause a wave to hit the oposite side of the tank giving it additional tipping momentum.

There is also the issue of a 50 foot tower being one hell of a long lever on a weight that is centered at 2 foot. That 25:1 ratio, combined with the liquid nature of your weight could, at the very least, lead to a wild ride for your mill.

What that weight might do is allow you to use a smaller guy system instead of eliminating it completely.

[DanG]

I've never seen wind rock hilltops! With gravity constant the towers mass, the base mass wouldn't allow more than ripples, if that. It's not like a tanker truck experiencing lateral forces or a dogs water dish getting nudged - anchored into soil it'd be dead weight.

Exploring further, what about the weeble furling mechanism, whole tower wobbles but doesn't fall down?