thoughts on freestanding tower

[defed]

i have stumbled on a couple of lattice towers.  one is 50', 4 leg, with a 10' square base.  the owner says it at one time had a mill on it.  the other i have yet to hear back on what the base size is and how many legs.

i know no one here can say for sure what it can support, but i've seen 100' towers made for 20' turbines that have a 12' base.  so i guess depending on how heavy the material it is made from, it should easily support a 10' turbine at 50' (maybe only 40'...haven't decided if i can go 50' yet).

the next question is....can it be made to tilt.  and will my town allow me to use it w/o an engineers stamp!  need to find out this stuff before i go buy one of them.

if anyone has any thoughts to offer, i'm all ears!

thanks!

[wpowokal]

defed,

        I have a 40' 3 leg tower they are the most common here in Australia it was made for a 10' wind turbine but the same towers are used for wind mills (water pumpers). This pic shows some of the tilting arrangement.

http://www.anotherpower.com/gallery/allans-place/windy_1st_raising

I use an "A" frame gin pole, and tie the middle of the tower to it as well as the top, when up it is secured with one 3/4" bolt.

If you need more detail just yell. Much of what a tower like this will hold does depend on angle iron cross section but equally the bracing being in good condition and how much concrete you put into the base.

The base footprint does increase with height and head diameter, try Googeling Pumper sites I have seen one that gave details on footings.

allan down under

[defed]

thanks Allan.

i see what you mean on the A-frame, pretty good idea.  i was looking at a site that has the 100' tower for a 20' turbine, and they give the material sizing for their tower.  so, i should be able to compare that to these other ones.

just need to make sure i don't need special engineering stamps and stuff from the town before i decide to buy one!

Dave

[wpowokal]

Dave,

Guess that depends where you live, if a tower was designed for a say 12' head as windmill (water pumper) then it should be easy to argue that a 12' wind turbine is no different, because it is not. As far as the loading on the tower they both present a a 12' solid disc.

I'm on a farm and because of that I guess I take a few liberties.

Allan down under

[defed]

i had the guy selling the tower measure the steel.  legs are 2" x 2" x 1/8" and the cross bracing is 1.25" x 1.25" x 1/8".  the angle looks a bit weathered, but still solid.  it has a ladder up the side as well.

the commercial tower i found specs for (140' tall!), if you had made a 60' tower from it, the base would have 2.5" sch 40 pipe for legs and 2" x 2" x 1/8" for cross bracing.  this also would have a smaller base of about 7' square compared to 10' square of the one i am looking at.  the commercial one was also rated for a 20' turbine, where i will use a 10'.

just wish it was closer so i could look at it in person before i go pick it up.

[Shadow]

I use both a 3 legged and 4 legged tower, I wouldn't be afraid to put a 20 foot mill on either one.They both tilt, one is 50 foot and one is 60 foot.If properly anchored it takes a hurricane to topple one.

[Timeless Turbines]

I have aproval from my twp. and county to use a 45'four post windmill tower to support a wind turbine. My tower is 2"x2"x3/16". Call me Larry Holmes (not the boxer)(734)341-4197. Fenton Mi.

[dlenox]

Dave,

I have a 3-legged 70' free standing lattice tower that is made by AN Wireless, it is their heavy duty HD70.

Before purchase I paid their engineers to 'work the numbers' and see if it would be suitable for my 17' wind turbine. They came back and - no problems - I have an engineering stamp for mine.

In talking with Dan Simmonds (founder) he stated that it should be able to take a larger turbine if in the future I upgraded.

I also have built a telescoping stub and davit crane at the top, as well as standing work platforms.

This tower base is only about 4' square.

Here are photos if you are interested contact me offline with questions (dlenox@briery.com)

Dan Lenox

[dlenox]

Dave,

Forgot to mention that I asked the AN Wireless engineers about converting the tower so that it could be hinged at the base - and they said absolutely NO.

Typical lattice towers are not meant to take the strain.

Dan Lenox

[defed]

have another lead on an unused, 3 leg, 3 section (20' each), approx 3' x 3' base, galvanized tower.  he says it is heavy duty, and has the original book (installation etc)for it.  will need to see if it gives any load info.  was originally $6k....selling for $500!!!  it's been sitting in storage since new.

for that price, presuming the sections will break down, i will most likely get it.  if i can't make it tilt...well...i'd rather make it tilt!