Tower Pipe

[Walter]

I am wondering about the merits of steel electrical conduit vs pipe for construction of a stayed tower.

It seems like on a per pound basis you  get a larger diamater in the conduit than in the steel, but of course the wall thickness is less. How does this translate into buckling strength of the column?

Then there is the dollar issue. For the same amount of $$$ which one gives the stiffest tower?

[TomW]

Walter;

I am certainly not any kind of expert but I do know that EMT "conduit" is intended to be used in applications where it will be bent to suit the application. That alone tells me it probably is not a good choice for any application requiring stiffness. Folks have built towers from it and there is at least one story in the archive on it but personally I would not trust it under the stress a wind turbine inflicts on it. Plus, I do not think it is galvanized on the inner surfaces so it could deteriorate pretty fast and there is no margin for loss of material in the tube.

Try a google search of the board using "EMT tower" and it may pop up.

Just my first thoughts.

Cheers.

TomW

[BigBreaker]

Conduit is not designed to be load bearing.  That right there is enough to nix it in my opinion.  Just because it is made out of metal, doesn't make it strong.

[wooferhound]

Electric conduit is fairly thin walled. If you tried to stack it as a tower, I don;t think each section would sit squarely on the last section to give it strength enough to hold something up. And how would you connect the sections together? Using a Conduit Coupler, I don't think so !?

Old F  was making a tower from 3/4" conduit. I never did hear the end results.

Here are the links . . .

http://www.fieldlines.com/story/2003/12/23/164812/25

http://www.fieldlines.com/story/2003/12/25/172023/12

http://www.fieldlines.com/story/2003/12/28/16295/835

http://www.fieldlines.com/story/2004/1/11/133953/158

[harrie]

Walter, there is thin wall conduit and heavy wall conduit. Heavy wall would work just fine. It would however put out toxic fumes when welded, but I do it all the time, just make sure your outside, and have the wind blow the smoke away from you. 4 inch heavy wall condiut, measures 4 inches on the outside dia, so it works great for sliping inside of 4 inch scedule 40 to make a stronger joint when welding pipe sections together. If you have the choice, I would use steel pipe!!

[Mickel]

Interesting reading. I am a novice still building my first genny (winding coils at the mo) but Ive been doing a fair bit of reasearch on everything so I (hopefully) know what Im going to do when I arrive. the tower advice Ive been given (my site is sloping and not easy to access, in light to moderate winds), and Im building an 80 footer is along the lines of the Bergey line of thinking. Using 4" outer diameter with thin wall 0.78" wall thickness. Guying it every 20ft. Im thinking of making a sleeve to fit over the top part of the pipe, welding it on one of them and letting the other part of the tower slip into it and stay loose. Maybe seal it with silicone so I dont get to much moisture in the pipe.

Then weld my guy lugs on each sleeve.

This is my current thinking and would be keen to hear a more 'seasoned' opinion. By the way this pipe is supposed to be available at an electrical contractors.

[tecker]

There's a standard size fence pipe that fits very nicely over 2" emt couple of screws and your done . I'm thinking 1 1/4 Imc is a good match interior for 2" .I'll check on the actuall sizes there .