Tower tube find

[fabricator]

Wow I found something cool today, in a local town there is an outfit that sets up feed grain handling equipment on farms, the big bins with long auger runs and all that stuff, I went over there and asked about the auger pipe they use, they get it in 40" sections, all galvanizeed, 10" dia has a 10gauge wall and is $20.95 per foot, 8 inch dia has a 12gauge wall and is $12.60 per foot, I'm sure I have found my tower, I'm gonna use the 8inch in two 40' sections, the galvanizing is the clincher for me, no painting, no nasty naked rusty tower, also there will only be one joint in the tower and none in the gun pole.

[ETech]

Just a quick reminder, welding galvanized pipe produces extreamely toxic fumes!

Please search the web about this hazard!

If you know about this already and are taking this in account great.

I just hate to see someone get hurt.

Second, Great find!

Have fun and be safe, ETech.  

[fabricator]

I have been a welder all my life, I have no intention of welding the joints, they will use half band connectors, they are much stronger in this application, with this type of tube than a welded seam.

[Wags]

Fabricator,

Looks like you got quoted the same prices I did. If I recall one of the Dan's put a 20'er on an 80' or 100' tower made of 10" 12 ga. I think. I am planning a 21' 5kw induction generator, weighing about 700 lbs on a 80' or 100' tower. I think your weight would probably be similar. Not being an engineer, I tend to over build, but sure would like to save the cost of the larger tubing if its not required. Are you planning two sets of guys at 40' and 80' then another piece up to the yaw assembly? It is the lightest tower I have read of on here for that size of machine, not saying can't be done, I would like to follow your lead, just wondering what some others might think about this. I also found another option, but I think it is to light for my needs. Used center pivot irrigation tubing. 6" - 12 ga. Galvinized 40' piece $100.00. Flanges welded on both ends, and pipe couplers welded in for spray nozzles, not sure of spacing. Seems a bargain, would I be stupid to put a machine this size on that?

I would really appreciate any input on this guy's, i am planning to get started on this when the weather brakes.

Thanks

Jeff

[fabricator]

Do a google search on tilt up towers there are lots of examples of commercially made towers up to 120' tall using 5' galvanized tube for machines in the 12-14' range, the eight inch 12ga wall is over kill when you look at these towers, I will have four sets of three guy wires, 24'-48'-72', with these towers it is all about the guy wires, I believe 2" pipe would hold a 17' turbine given enough guy wires.

[taylorp035]

Maybe for the bottom part, but I doubt the very top could be 2" because there can't be any wires at the top.

8" does seem a little over kill for the bottom.

[SparWeb]

"2" pipe would hold a 17' turbine"

I don't think so.  3" is just enough for an 8-10' machine like mine.  I'd up-size the tower for such a large turbine, and it's not only about the guy wires.

[Wags]

I know there are lots of variables, but would you be comfortable with the 6"-12ga. up to the connection point of the top set of guy's? Assuming 3-sets of guys, with a 700 lb. 21'  5kw unit on top. I have seen the 5" tube towers, but could not find what wall the tube was. This stuff looks like a great bargain, but sure would be costly if it failed.

Thanks

Jeff

[fabricator]

I don't know about 6", that is a big rotor on 6" tube, my 17' only weights about 375lbs.

[SparWeb]

"This stuff looks like a great bargain, but sure would be costly if it failed"

Which is why we shouldn't just "shoot from the hip" on these choices.  The tower must be strong enough for the entire process of construction, raising, supporting the turbine, and later lowering.  I find raising my tower puts more stress on it than when it's up, but it's a lot harder to analyze that condition.

[Ungrounded Lightning Rod]

Top set of guys should be to the middleish of a section of pipe, not to a joint.

Wind force on the mill at the top of the tower will put a maximum bending load at the location where the top guys connect.  Not good for joints to be there.

[fabricator]

That is exactly why I said I would not be comfortable with 6", the bending force on 6" at the last set of guys with a 20 rotor would be very scary, like bending a wire back and forth sooner or later the tower would snap and it would be a very bad day for the owner.