free standing tower

[methanolcat]

here are a few pic's of the free standing tower I am working on, it will be 50 feet tall and 8 foot square at the base. I have alot of younger as well as older kids (including me) riding 4 wheelers around this property so I didn't really want any guy wires that someone might possibly get hurt on.

      it's made from 80 feet of 2x2 angle iron, 480 feet of 3/8 round rod, 168 feet of 1/2 round rod and 12 feet of 4" pipe, which 2 feet of that pipe will be inside 2 feet of 7" pipe that is welded to the top. It will extend 10' above the tower allowing me to use a prop of almost 20' diameter if need be in time.

    there are 7, 1" adjusting bolts at the top that will be used to adjust and secure the 4" pipe as straight up as possible.

 I figured I would post this since I havn't seen too many freestanding towers on here.

    There will be a crows nest of 4 feet square near the top to stand on and install the gen and blades. there will also be a hand crank winch near the top for raising and lowering the 4" pipe, NOT SHOWN IN PIC'S YET.

    There will be 2 heavy hinges on 2 of the legs to help in raising so it doesn't try to walk away, once standing the feet will be bolted to 4" pipes 12' to 15' deep in the ground that will be cemented in.

     The tower itself as seen in pic's weighs 500 pounds, there will also be a permanant ladder welded to it which will reach from the top to 10' from the ground, that will keep children from climbing the tower, I will use a attatchable ladder at the bottom or a short extension ladder.

     I have built the ladder as well from 1" square tube and 1/2 inch rod, just no pic's of it yet.

     I swapped doing work in trade for the steel, but I had it quoted and at current prices the tower with ladder and crows nest would cost right at 500 U.S. dollars. I will scrounge for pipe to go into ground as it wouldn't matter what it looked like as long as it was strong, could be rusty, pitted, whatever.

Tower was constructed in the shop where I work in just one day, one very long day at that.



Brought it home on my race truck trailer using country roads because it was hanging off the back about 5 feet



the tower will remain in 2, 20 foot sections that will be bolted together, in case I move, it's going with me. I hope to have it completed and standing in the next month or so, more pic's at that time.

      Any comments, questions or advise are appreciated greatly

      One question from me, Does anyone on this board live in or near Indiana and have any type of wind gen flying?

[thefinis]

How are you anchoring it to the ground? It will need quite a bit of footing/concrete if it is to handle up to a 20' turbine. I like the compactness of a freestanding tower but worry about how to get the turbine up and down for changes and repairs. I have seen some pictures of ones that hinged in the middle for working on the turbine. I had an idea for a freestanding tower but have no idea if it was a good one. Run a cable down the center to an anchor. Anchor could be many things but would be eye bolt in the concrete base if one is used. This should help hold it but loads the tower however tower loading is going to occur in high winds anyway.

My daughter is here from Germany and says that some of the bases there use wind power and have had their turbines on the round freestanding towers but that the new ones going up are lattice towers much like yours. Wish I knew why the change could be weather related or availability or price of steel.

Finis

[calchuck]

I bought a free standing tower very similar to yours and the same hight. I poured the large deep pad and put in lots of steel and three 1" dia anchor bolts. I welded in some support structure on the tower to help with the stress at the bottom when raising this much weight. The same week the County Building Inspector came by and said I would either have to take it down or face a fine. They require an engineer's stanp to verify that the tower will withstand the wind load for the weight and height. I have it down right now and haven't figured out yet what I am going to do.

Some kind of gin pole might be nice but would have to add some structure to the bottom for support. Looks good, have fun.

[Shadow]

I have two lattice style towers. One is 50 feet and the other 6o feet high.I built them to pivot on two legs and they take about 15 minutes to raise or lower. One had a 14 foot turbine the other a 12 foot. The towers survived the high winds easily ..the wind turbines didnt.

Both are three legged towers, more pictures in my files.

[adobejoe]

Made ours out of pipe, three sections for 55' and supporting a 10 KW unit.  Three years in August and I am sure we have had 80 mph winds.

AdobeJoe

%>

[methanolcat]

very nice shadow

  would you describe your footing for me? what you used and how much?

[etownlax]

AdobeJoe,

You tower looks really cool. What is the diameter of each section

and the thickness?

I'm sure that cost a whole lot. I think its still worth looking into.

Thanks, Randy

[adobejoe]

Randy:

Three sections 22" dia 18"dia and 13" dia.  EAch 20' but slipsleeved with collars about 18" within. Built it a few years ago of old salvage oil field pipe (lots of that in Wyoming).  Footing has 12 yds high stregth concrete with 8' J bolts.  

[etownlax]

Sweet. Thanks for sharing AdobeJoe

-Randy

[ddrew]

Hey Methanolcat, nice tower. I recently found a commercially built HAWT with a similar free standing tower. Unfortunately, I got it second hand (the guy I bought it from disassembled it, and hauled it to his home) and he didn't get any blueprints or specs on it. It is a 50' 4 sided, 4 section tower that is 8' sq at the base and 3' sq at the top. It's all angle iron and bolted together. I'm still trying to figure out how much footing/foundation to build under it. Since the existing generator is locked (not sure if it just furled or has a mechanical problem), I'm thinking of keeping the generator on the ground and put a VAWT on it. I am thinking about using 1" or 1 1/2" sch 40/80 pipe as the shaft. I'm still in the design stage, and would appreciate any and all suggestions about how to figure footing/foundation sizes, as well as VAWT design loading specs.  

Luckily I don't have building inspectors to worry about, but I definitely want to build it strong enough to withstand the weather that we have around here in North Texas.

[thefinis]

Before changing everything up I would see what shape the existing unit is in now. The size of the area the turbine sweeps will help determine the footing needed. A system with the ability to furl lowers the forces seen by the tower in high winds. Hopefully the turbine and the tower are matched now.

If you want to build a vawt then I would start with a smaller one on its own short tower or if you are in one of the areas with few trees mainly grassland(where in north Texas?) just a 10 ft stand might work. Not trying to talk you out of replacing the unit on the tower with a vawt but I would play with vawts a little and learn more about them before making the big step of replacing the turbine that came with the tower.

Here is a link to another forum with a topic of footing forces and weights needed for a free standing tower.

http://www.thebackshed.com/Windmill/FORUM1/forum_posts.asp?TID=252&PN=15

There are several threads here including one recent one that talk about wind forces seen which helps to determine footing needed.

Finis

[ddrew]

Thanks Finis, great advice! I'm in Springtown (just west of Ft Worth), and the tower and turbine appear to be matched. I got a photo from the seller, of the windmill when it was standing near Wuest, Tx. I'll scan it, and post it to see if anyone can give me a better ID on it. I'm not sure of the furling capabilities, and that's why I'm hoping someone can help ID this for me.

I agree that experimenting with a VAWT is a good first step, and I'll definitely do some testing before installing anything on this tower. Thanks for the link on tower footing designs, and I'll definitely look through the materials before I start digging.

I'll get some pictures of the running gear, and detail the construction better in another post.

Thanks,

Dale

Springtown