Author Topic: Are Using Monopole Towers Taboo?  (Read 39575 times)

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doubledipsoon

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Are Using Monopole Towers Taboo?
« on: May 24, 2011, 08:49:42 PM »
I bought a nice used Bergey XL-1 off EBay last year, and was also able to get a dozen old Arco 16-2000 solar panels. The clone-like Zomeworks Tracker is done, as is the battery room. There is one huge hitch to my far out project- how to get any reliable info on self-supporting mono-towers. I hate guy wires and I don't have the time to build a narrow 3-legged "miniaturized" Rohn SSV tower. I've got my eyes on a 40 foot 5.5 O.D. steel pipe, with 3/8" thick walls. I called Mike Bergey, and he said that self-supporting monopoles towers would "get me in trouble". A little voice in my head kept telling me that he probably was discouraging me so I'd buy one of his ugly looking 4-tiered multiple guy wire set-ups. It's hard to believe that Altamount Pass is littered with all types of wind generators using super-thin toothpick looking monopoles on wind generators with huge blades. How on Earth can't one of these handle a little 4-foot bladed toy like the XL-1? I think I'm the first person on Planet Earth to want to put an XL-1 on a monopole. Yes? Joe

SparWeb

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Re: Are Using Monopole Towers Taboo?
« Reply #1 on: May 24, 2011, 11:08:51 PM »
You called Bergey, but you didn't call Rohn.  Since you want a monopole tower, they can sell you one.  Sized for the XL-1 even.  Engineered.  The works.

It isn't a 5.5 OD tube.  The reason for that is very very important.  If you don't want wires, you need diameter instead.  Like 12" diameter, heavy walled, lots of concrete in the base. 

The towers aren't toothpicks when you get up close, and it's not XL-1's that stud the Altamont pass.  It's not a very relevant comparison.
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doubledipsoon

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Re: Are Using Monopole Towers Taboo?
« Reply #2 on: May 25, 2011, 12:00:54 AM »
     Sparweb, thanks for the info, but even your info is irelevant- any tower for the XL-1 cannot extend out more than 5 inches, from a point 4 feet down from the blades- which means that the largest diameter tube can only be 10 inches. It all seems like overkill for three spinning 4-foot blades, but what do I know. If a 5 inch monopole for an old whisper H-40 (3'5 foot blages) cost $2700, (I don't even know if they still make them) I'm sure your 12 inch diameter monotube would be over 10 grand. Now, does that seem like a cost-effective and simple solution?

Volvo farmer

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Re: Are Using Monopole Towers Taboo?
« Reply #3 on: May 25, 2011, 07:37:35 AM »
Quote from: doubledipsoon

      Now, does that seem like a cost-effective and simple solution?



A cost-effective and simple solution would be to use guy wires, but you don't want to use ugly guy wires. That leaves you with the not-cost-effective and not-so-simple solutions.

Seems like nobody is telling you what you want to hear. What does that Mike Beregy guy know anyway? He's just a tower salesman right? I say you should go ahead and ignore all engineers and people who make their living in this industry and erect your 5.5"  tower just to prove them all wrong.
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Re: Are Using Monopole Towers Taboo?
« Reply #4 on: May 25, 2011, 08:49:28 AM »
     Sparweb, thanks for the info, but even your info is irelevant- any tower for the XL-1 cannot extend out more than 5 inches, from a point 4 feet down from the blades- which means that the largest diameter tube can only be 10 inches. It all seems like overkill for three spinning 4-foot blades, but what do I know. If a 5 inch monopole for an old whisper H-40 (3'5 foot blages) cost $2700, (I don't even know if they still make them) I'm sure your 12 inch diameter monotube would be over 10 grand. Now, does that seem like a cost-effective and simple solution?

So I am definitely not an engineer - and even engineers get it wrong with regard to towers often times (especially ones that tip up and down).  But -  I'd just be really careful here.  First, 40' is a pretty short stick - do you have any trees or buildings between the site and the prevailing wind?  A monopole is fine - but as folks  have pointed out, it is absolutely the most expensive tower you can build.  It would be a shame to spend so much, and have your turbine too close to the ground where the performance maybe dismal.

If SW windpower used to put H40's (7' diameter machine) on monopoles that were 5" diameter, then I would not dare to put a larger machine on pipe that's smaller.

I believe I am correct to say that the strength of your tower is related:
directly to the wall thickness of the pipe
and to the *cube* of the diameter.
so keeping the wall thickness fairly thin and the diameter large will be your best bang for the buck - and if you decide to 'play' I expect that for the same price as 4.5" thick walled pipe you could by 12" thin walled tubing that weighs about the same but would be much more rigid.  And then the top 4' or so should obviously be smaller stuff to provide for blade clearance.

Again though  - putting a turbine on a 40' tower will probably yield poor results.  I maybe wrong here, but it's my understanding that Bergey will not allow a certified installer to put any of their machines below 60'.

So....  are monopoles taboo? - no, just expensive.  40' towers are taboo though ;-)
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fabricator

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Re: Are Using Monopole Towers Taboo?
« Reply #5 on: May 25, 2011, 05:30:28 PM »
     Sparweb, thanks for the info, but even your info is irelevant- any tower for the XL-1 cannot extend out more than 5 inches, from a point 4 feet down from the blades- which means that the largest diameter tube can only be 10 inches. It all seems like overkill for three spinning 4-foot blades, but what do I know. If a 5 inch monopole for an old whisper H-40 (3'5 foot blages) cost $2700, (I don't even know if they still make them) I'm sure your 12 inch diameter monotube would be over 10 grand. Now, does that seem like a cost-effective and simple solution?

I'm pretty sure you are incorrect in your figures there, that turbine has a tilt back built into it which puts the blades farther away from the tower at the bottom of the rotor disc.
I am in the process of having a sixty foot monopole built by ARE, a monopole is a bit of a misnomer, they are a single tube but they are always tapered, a sixty foot monopole is almost twenty inches in diameter at the base and six inches at the top.
Even the best tower is only as good as it's foundation, my tower will take somewhere in the neighborhood of five to six yards of concrete, which is ten or twelve tons.
For a lot of folks like me it's about zoning restrictions, not cost effectiveness, more and more local units of government are drafting ordinances that are de facto bans on residential wind, if you have a wind ordinance or any kind of building code which requires a permit to put up a tower where you live, there is no way you will ever get any building inspector to give you a permit without an engineers stamp on your tower, and from painful experience I can guarantee you there is no engineer licensed to stamp a drawing that will put his stamp on a tower like you propose.
On the other hand, if you live where there are no codes, just do it, just keep the fall zone away from property lines, power lines, or buildings and put a fence around it and stick it in a big hunk of concrete
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B529

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Re: Are Using Monopole Towers Taboo?
« Reply #6 on: May 30, 2011, 02:27:33 PM »
I bought a nice used Bergey XL-1 off EBay last year, and was also able to get a dozen old Arco 16-2000 solar panels. The clone-like Zomeworks Tracker is done, as is the battery room. There is one huge hitch to my far out project- how to get any reliable info on self-supporting mono-towers. I hate guy wires and I don't have the time to build a narrow 3-legged "miniaturized" Rohn SSV tower. I've got my eyes on a 40 foot 5.5 O.D. steel pipe, with 3/8" thick walls. I called Mike Bergey, and he said that self-supporting monopoles towers would "get me in trouble". A little voice in my head kept telling me that he probably was discouraging me so I'd buy one of his ugly looking 4-tiered multiple guy wire set-ups. It's hard to believe that Altamount Pass is littered with all types of wind generators using super-thin toothpick looking monopoles on wind generators with huge blades. How on Earth can't one of these handle a little 4-foot bladed toy like the XL-1? I think I'm the first person on Planet Earth to want to put an XL-1 on a monopole. Yes? Joe

Your little voice in your head is dead wrong. Mike Bergey is not giving you sound advice with the hope of selling you one of his towers, he's trying to help you, listen to him. He does not want to see one of his turbines hit the ground, as I'm sure you don't as well.

You are not the 1st person wanting to put up a XL-1 on a monopole, I know of one on a 60' Rohn monopole. The tower is probably 2-3 times the cost of the turbine.




doubledipsoon

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Re: Are Using Monopole Towers Taboo?
« Reply #7 on: May 30, 2011, 06:59:31 PM »
       Thanks for all the feedback on the possibility of  incorporating a "monopole" onto a Bergey XL-1 wind generator. The little voice in my head has concluded that a $4000 pole is like using a wind generator with no wind. (Uh, let's see now, a 9 year payback, just for the monopole- even with 18 mile an hour winds that blow all day)....
        Wind generation has taken some wierd twists and turns over the years. Cost-effectiveness in definitely not one of them. Sorry if I insinuated if Mike Bergey came off like he wanted to sell me one of his cheepo, multi-guywire gizmos, but that's exactly what happened.
        I even called Rohn. Sure they make a SSV self-supporting tower that would work, for around 7 grand- another road I aint goin' down. The only way wind is going to be cost effective for me is to build a self supporting Rohn clone tower for about 1/7th the cost of buying one new- yes, my friends, 1/7 the cost. If you guys want to support corporations and their fat profits, be my guest. I'll be having a blast doing a grass-roots, low tech version of what wind power should be all about. Joe

zvizdic

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Re: Are Using Monopole Towers Taboo?
« Reply #8 on: May 30, 2011, 07:32:37 PM »
No one here  is going to give you advice and endanger your surroundings.

If you are capable of building one and have know how go ahead .

This is a group of people helping each other, same of them are a professionals in different fields or with a lot of experience .

You well get different opinions but no one well tell you to put a 8' machine on a 40' 4.5" monopole.

fabricator

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Re: Are Using Monopole Towers Taboo?
« Reply #9 on: May 30, 2011, 07:58:32 PM »
I have been a steel fabricator for 32 years, I'm a certified structural welder along with several other certifications, I could build a tower to support my 17' machine in my sleep, but like I said some places require an engineers stamp to issue a building permit, sure I could build a tower for 2-3000 bux but an engineers stamp would cost 2-3000 bux.
So for 6K I can have a self built tower or for 6K I can have somebody else do the labor, do the math.
One more thing you need to consider, if you have grid power and you are putting up a wind turbine to save money or lower your bill you are kidding yourself, you CANNOT generate wind power cheaper than you can buy power from the grid GUARANTEED end of story.
Most here are doing this for a measure of self sufficiency and because it is the right thing to do.
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Hilltopgrange

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Re: Are Using Monopole Towers Taboo?
« Reply #10 on: May 30, 2011, 08:09:27 PM »
You don't have to buy a tower! a lot of folks build their own. The pipe tower is only one option, I prefer latice towers but it is a lot of work to build them. I posted a write up on the last one I built here

http://fieldlines.com/board/index.php/topic,143821.msg968663/topicseen.html#msg968663

 total cost was about £250, you don't have to spend a fortune but you do need to be sure of your ability with a welder.
 
Russell
How many windmills do I have to build to become a windmillologist?

zvizdic

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Re: Are Using Monopole Towers Taboo?
« Reply #11 on: May 30, 2011, 08:14:14 PM »
Some people like to fish some to hunt I like to play with my windmill .
Most here are doing this for a measure of self sufficiency and because it is the right thing to do.

fabricator

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Re: Are Using Monopole Towers Taboo?
« Reply #12 on: May 30, 2011, 08:29:43 PM »
Some people like to fish some to hunt I like to play with my windmill .
Most here are doing this for a measure of self sufficiency and because it is the right thing to do.


Exactly, I see it as a hobby, and my insignificant way of sticking to big oil and king coal, it kinds of an elephant and flea situation but what the hell it's fun to make electricity from two forces of nature.
I aint skeerd of nuthin.......Holy Crap! What was that!!!!!
11 Miles east of Lake Michigan, Ottawa County, Robinson township, (home of the defacto residential wind ban) Michigan, USA.

doubledipsoon

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Re: Are Using Monopole Towers Taboo?
« Reply #13 on: May 30, 2011, 08:43:24 PM »
          I'm very aware of the math about why wind or solar can never really compete against oil (something to do with the molecular energy bound in the oil molecule vs a photon or alternator) and yes. I'm doing the Bergey/photovoltaics because it's the right thing to do.
          I'm fortunate because I live on 200 acres and don't deal with regulations very well. I do what I like- no codes, no regulations, no problems. I anticipated this years ago.
          So what do you think?- a 40 foot 3-legged self-supporting tower with 3"x 3"X 1/4" angle iron anchors, the first 2 eight-foot sections in 2.5"X 2.5" X 3/16" angle iron, the rest in 2" X 2" X 1/8" angle iron, with criss-crosses (like a Rohn SSV tower) every 4 feet, all the way up, in 1.5" X 1'5" X 1/8" angle iron............The only gliche will be the 15 degree difference between the 45 degree angle iron and the 30 degrees needed for 3 legs, if you know what I mean- I'll probably have to weld some off-set fasters or use "beveled washers" ,don't know yet...Joe

joestue

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Re: Are Using Monopole Towers Taboo?
« Reply #14 on: May 30, 2011, 10:05:08 PM »
this may sound ridiculous to some...  If i was in your position i would build two 8 foot sections similar to how you described, weld them to a suitable frame, stick a 40$ dollar walmart 20 ton bottle jack equipped with a 20$ 10,000 psi hyd gauge and test to failure. you might need more than 20 tons but that entirely depends on how well your bracing is constructed/

btw, angle iron is less than useless unless its free. under compressive load its going to rotate/twist and buckle sideways at much lower loads than a pipe of equivalent cross sectional area will (same diameter as the width of the angle iron).
« Last Edit: May 30, 2011, 10:07:21 PM by joestue »
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zvizdic

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Re: Are Using Monopole Towers Taboo?
« Reply #15 on: May 30, 2011, 10:09:38 PM »
         I'm fortunate because I live on 200 acres and don't deal with regulations very well. I do what I like- no codes, no regulations, no problems. I anticipated this years ago.
    

200 acres I go with what ever i fill comfortable with.  

doubledipsoon

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Re: Are Using Monopole Towers Taboo?
« Reply #16 on: May 30, 2011, 11:43:52 PM »
        It's hard to believe that angle iron is useless for a wind generator, since Jakes themselves were perched on them for decades with virtually no failures. I took down a Jacobs 1800 (300 lbs) off a 60 foot angle iron tower (2 1/2"-3" angle iron) from the Synergia Ranch in New Mexico that didn't seem to mind. I mean, a Jake has a 3- 7 foot sitka spruce blades that put out a hellava lot more lateral thrust than a "toy" Bergey XL-1 (3- 4 foot fibre-blades)...This is why I love this site so much!!!!!

fabricator

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Re: Are Using Monopole Towers Taboo?
« Reply #17 on: May 31, 2011, 06:24:57 AM »
btw, angle iron is less than useless unless its free. under compressive load its going to rotate/twist and buckle sideways at much lower loads than a pipe of equivalent cross sectional area will (same diameter as the width of the angle iron).

Hmmm, can you please explain ho Rohn, Bergy, Jacobs, Aeromotor, and countless cell phone towers and power transmission towers get away with this useless angle iron? some of these towers are 100+ feet tall and have been standing for close to 100 years.
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TomW

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Re: Are Using Monopole Towers Taboo?
« Reply #18 on: May 31, 2011, 07:09:23 AM »
btw, angle iron is less than useless unless its free. under compressive load its going to rotate/twist and buckle sideways at much lower loads than a pipe of equivalent cross sectional area will (same diameter as the width of the angle iron).

Hmmm, can you please explain ho Rohn, Bergy, Jacobs, Aeromotor, and countless cell phone towers and power transmission towers get away with this useless angle iron? some of these towers are 100+ feet tall and have been standing for close to 100 years.

Joe;

I get this feeling you are not used to being challenged when you make statements.

Welcome to peer review!

The entire Midwest and Plains states were covered with thousands of water pumpers all perched on angle iron towers. Many of them 60 feet and higher. And a good few that survived literally decades in some harsh environments including twisters. At least until the hippies went around and collected them in the '60s and '70's. Got a 60 footer here and it is the one I never worry about.

That makes your "useless" statement, well, uh, ludicrous.

Ya gotta believe what you believe even if it is wrong.

Just the reality here.

This time I have to point out  the completely and utterly wrong  information you are posting.

Literally thousands of turbines are held up with angle iron and will be for decades.



Tom

Rob Beckers

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Re: Are Using Monopole Towers Taboo?
« Reply #19 on: May 31, 2011, 08:02:16 AM »
Not mentioned yet in this thread, there is another very important reason why you can't just stick any wind turbine on any self-support tower (including and especially monopoles): The combo of tower plus turbine will resonate at certain frequencies. For those in the structural engineering world this is referred to as first and second natural modes. If your turbine happens to generate those frequencies, or anything close to it (blade imbalance will do that, no matter how well balanced your blades are) it will resonate violently, and either the tower, turbine, or both will break. I've seen the results when this goes wrong, it's no joke. That means the tower and turbine need to be engineered to work together, the first natural mode had to be low enough so the blade RPM doesn't excite it, the second mode high enough to again fall outside the RPM range.

Paradoxically, the cases where I've seen this go wrong in a big way were towers meant for far larger wind turbines that were 'recycled' with a smaller turbine on top. Strong towers without a lot of weight on top have high resonance frequencies, making it more likely that they coincide with the rotor RPM of a small turbine.

Now you know why sticking a little XL.1 on just any monopole is rolling the dice...

Incidentally, guyed towers also have a first and second natural mode, but it depends on how tight the guy wires are. Those guy wires also provide a lot of damping, making the impact of resonance less destructive. That means this engineering is not done for guyed towers; you simply adjust the guy wires as needed if resonance is observed.

-RoB-

Ungrounded Lightning Rod

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Re: Are Using Monopole Towers Taboo?
« Reply #20 on: May 31, 2011, 10:47:33 AM »
The issue with monopole towers is leverage.  The long arm of the lever is the height of the tower.  The short arm of the lever is the width of the base.  The forces on the base of the tower (and bending the bottom of the tower) are multiplied by the ratio of the height to the width.

If you put up a tower that's a 5.5" pipe all the way down, and manage to get it up intact, it will buckle like a soda straw near the base when the first breeze spins up your rotor to cutin (and the load on the blades makes them start slowing the wind almost as much as a solid disk of their diameter).

Monopole and lattice towers get away with it because they get wider (and usually also stronger) as you get lower.  It's hard to see on a solid monopole, because perspective also makes the top look smaller than the base and it fools the eye.  But look at an unguyed radio broadcast tower:  It is tiny at the top, broad at the base, and may also curve outward toward the base somewhat trumpet-wise if it's optimized.  And it only has to support its OWN wind load, not this enormous disk whose whole purpose is to slow down the wind as it collects its energy.

A monopole also need that enormous, solid, reinforced concrete base because the lever also applies to the weight of the concrete fighting the forces trying to tip the tower.  Half the weight of the must be significantly greater than the sidewise force on the top of the tower multiplied by the ratio of the height of the tower to the width of the pad.  (Significantly greater - like another factor of 2 - because the ground under it doesn't act like a fulcrum at the edge of the downwind side, but more like one closer to the cetner.)

Guyed towers get away from this because the width of the base is the width of the guy anchor footprint and the short lever arm is from the base of the tower to the guy anchors.  Meanwhile the strongest bending load is at the top guy attachment, not the base, and the numerator length is the distance from there to the top, not from the base to the top.  The pipe is mostly loaded in compression and its main problem is to not buckle - and one or more additional guys along its length take most of THAT job off it as well.

So a solid monopole to support a large rotor's area against a wind load is an engineering feat that requires serious math and fabrication skills and facilities, not something you find at a pipe supplier (though you CAN find them commercially).  A monopole lattice tower is a lot of work (and nontrivial math) but within reach of a homebrewer.  And a guyed pipe is easy and cheap - even if some find it ugly and the guys a nuisance.

doubledipsoon

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Re: Are Using Monopole Towers Taboo?
« Reply #21 on: May 31, 2011, 12:14:21 PM »
Hey TomW, Joe here- I'm the one advocating angle iron for a wind generator tower....Don't pick on me....in the future check out WHO'S posting WHAT, later, Joe.....

doubledipsoon

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Re: Are Using Monopole Towers Taboo?
« Reply #22 on: May 31, 2011, 12:23:00 PM »
        Hey Fabricator, those corporations are all involved in "overkill" and huge profits in their new generation of wind generator towers....The abandonment of angle iron into the tower equation is one real good example of why you have to mortgage your house to get into wind energy. Yeah, I know that round pipe is stronger than the same width angle iron, (like Rohn uses) but it weights almost twice as much, and isn't always necessary, as the Jacobs/Wincharger era showed. I may be in love with the past, but it was also alot more low-tech, cheaper, and simpler to do.....(they still use angle iron in the cross-sections, so there!, all you corporate worshippers)

joestue

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Re: Are Using Monopole Towers Taboo?
« Reply #23 on: May 31, 2011, 12:58:50 PM »
btw, angle iron is less than useless unless its free. under compressive load its going to rotate/twist and buckle sideways at much lower loads than a pipe of equivalent cross sectional area will (same diameter as the width of the angle iron).

Hmmm, can you please explain ho Rohn, Bergy, Jacobs, Aeromotor, and countless cell phone towers and power transmission towers get away with this useless angle iron? some of these towers are 100+ feet tall and have been standing for close to 100 years.

Joe;

I get this feeling you are not used to being challenged when you make statements.

Welcome to peer review!

The entire Midwest and Plains states were covered with thousands of water pumpers all perched on angle iron towers. Many of them 60 feet and higher. And a good few that survived literally decades in some harsh environments including twisters. At least until the hippies went around and collected them in the '60s and '70's. Got a 60 footer here and it is the one I never worry about.


that's where the cost-time-material-brains required trade off comes from.... "unless its free" [or dirt cheap]

if OP can get 5.5 inch diameter 3/8th inch thick pipe... he can probably get iron scrap by the pound.. and by the pound, pipe  is at least twice as strong as angle iron for slender columns. the pipe will probably be a stronger steel anyway.

If you want to burn up 3 inch angle iron go ahead, but if you're paying by the pound, please reconsider!
My wife says I'm not just a different colored rubik's cube, i am a rubik's knot in a cage.

TomW

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Re: Are Using Monopole Towers Taboo?
« Reply #24 on: May 31, 2011, 01:34:00 PM »
Hey TomW, Joe here- I'm the one advocating angle iron for a wind generator tower....Don't pick on me....in the future check out WHO'S posting WHAT, later, Joe.....
Dip;

Not you.

Read the quote. Read your own comment its bass ackwards first you claim it is you then it is not? Might find value in proof reading and our preview option. Might not

Lots of "Joes" here.

Does anyone actually read what is written or do they just react to whatever ticks them off?

I decided you cannot be informed beyond what you already have decided about your 3rd post so I pretty much ignore you myself except when you misquoted my comment here.

Now you stop picking on me!

Tom

fabricator

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Re: Are Using Monopole Towers Taboo?
« Reply #25 on: May 31, 2011, 04:37:34 PM »
btw, angle iron is less than useless unless its free. under compressive load its going to rotate/twist and buckle sideways at much lower loads than a pipe of equivalent cross sectional area will (same diameter as the width of the angle iron).

Hmmm, can you please explain ho Rohn, Bergy, Jacobs, Aeromotor, and countless cell phone towers and power transmission towers get away with this useless angle iron? some of these towers are 100+ feet tall and have been standing for close to 100 years.

Joe;

I get this feeling you are not used to being challenged when you make statements.

Welcome to peer review!

The entire Midwest and Plains states were covered with thousands of water pumpers all perched on angle iron towers. Many of them 60 feet and higher. And a good few that survived literally decades in some harsh environments including twisters. At least until the hippies went around and collected them in the '60s and '70's. Got a 60 footer here and it is the one I never worry about.


that's where the cost-time-material-brains required trade off comes from.... "unless its free" [or dirt cheap]

if OP can get 5.5 inch diameter 3/8th inch thick pipe... he can probably get iron scrap by the pound.. and by the pound, pipe  is at least twice as strong as angle iron for slender columns. the pipe will probably be a stronger steel anyway.

If you want to burn up 3 inch angle iron go ahead, but if you're paying by the pound, please reconsider!

Nope sorry, you can make statements like that all you want, just posting it more won't make it right, a properly engineered structure made of angle iron will be just as structurally sound pound for pound, cross section for cross section, however you want to measure it than the same structure made from round tubing.
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joestue

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Re: Are Using Monopole Towers Taboo?
« Reply #26 on: June 01, 2011, 04:40:34 AM »
15 seconds with a rolled up postit note and a coffee mug proves that statement false.
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fabricator

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Re: Are Using Monopole Towers Taboo?
« Reply #27 on: June 01, 2011, 06:23:34 AM »
When you have something worthy of a response please post it.
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doubledipsoon

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Re: Are Using Monopole Towers Taboo?
« Reply #28 on: June 01, 2011, 07:56:17 AM »
         I've pretty much abandoned the monopole possibility for a wind generator. Why? Mainly because it's not cost effective on any level. Some very smart engineers can figure it out (when they're not disagreeing), but you'll have to pay for it big time, because it's all become "proprietary info", with huge price tags. It all dead-ended when Mike Bergey told me on the phone, "You should hire an engineer". Gee, thanks.
         Whether i'll construct a self-supporting lattice tower made of angle vs round steel tubing is all up for grabs, kids. What's the verdict? (Think we could come to an agreement without killing one another?)
       

joestue

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Re: Are Using Monopole Towers Taboo?
« Reply #29 on: June 01, 2011, 09:36:37 AM »
"You should hire an engineer". Gee, thanks.
what exactly did you ask him?

Quote
        Whether i'll construct a self-supporting lattice tower made of angle vs round steel tubing is all up for grabs, kids. What's the verdict? (Think we could come to an agreement without killing one another?)

no, not until we can agree on the laws of physics.

Quote
When you have something worthy of a response please post it.
paper not good enough for you? perhaps cardboard would suffice? plastic? its the same thing. the difference is the ratio between the two results obtained.
do you really think angle iron is even comparable to an equivalent weight of steel pipe? (same steel, etc, etc)

whats the first thing i notice about this photo?
http://www.w8ji.com/images/towers/Gin%20pole/polefullside.jpg
Its dirt cheap to manufacture. about the only thing worth arguing about is which will break first, the flange welded to the pipe or something else.

http://www.usedtowers.com/MONOPOLES/PHOTOS/TOP.jpg
here's an example of less than optimal bracing. the horizontal members are longer than they are square, because it was cheaper to do that then increase the diameter of the three poles. who knows if the design was actually optimized, how many manufacturers do you get to choose from?

http://www.vectorsite.net/Yivhv_3b.jpg
rivets. cheaper, faster than welding. does wonders on the strength of the joint.
« Last Edit: June 01, 2011, 09:41:03 AM by joestue »
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Ungrounded Lightning Rod

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Re: Are Using Monopole Towers Taboo?
« Reply #30 on: June 01, 2011, 11:25:14 AM »
         I've pretty much abandoned the monopole possibility for a wind generator. Why? Mainly because it's not cost effective on any level. Some very smart engineers can figure it out (when they're not disagreeing), but you'll have to pay for it big time, because it's all become "proprietary info", with huge price tags. It all dead-ended when Mike Bergey told me on the phone, "You should hire an engineer". Gee, thanks.
         Whether i'll construct a self-supporting lattice tower made of angle vs round steel tubing is all up for grabs, kids. What's the verdict? (Think we could come to an agreement without killing one another?)
       

Angle iron has the advantage that you can easily achieve strength in a bolted joint.  This lets you build a solid tower with only cutting tools, drills, and wrenches.  Getting good strong joints among pieces of pipe is more problematic.

The angle is about keeping the structure from buckling under compression and to achieve a significant improvement in strength against bending.  Same principle as the I beam (though not as good), but far simpler to fabricate.  Lattice structures only load the angle iron in tension and compression so it's perfectly adequate for the service.

(The bit about only being good in tension and not compression is true about a flat piece of metal.  But the whole point of the 90-degree fold is to make it false for angle iron.  It is not so good about strong bending forces at certain angles, which cause the fold to UNfold.  But if it's loaded in essentially pure compression - as it is when it's built into a lattice structure - that's not an issue.)

SparWeb

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Re: Are Using Monopole Towers Taboo?
« Reply #31 on: June 01, 2011, 02:44:40 PM »
I think this thread got off on the wrong foot.  I didn't expect it to continue for long after my initial comment.  I was a bit glib, so maybe I'm partly to blame.
Since we're still at it, I think there's a bit of a culture clash going on.  I'm pointing it out because it's causing pointless argument.
If people just respected the opinions of others - no matter how different they are from their own - there would be no need to snipe.
Folks also have to come to a discussion prepared for these different opinions.
I'm not sorry that people can't agree (when did that ever happen?) but I am sorry it turns into a squabble.

I won't contribute any technical thoughts because I can already tell the OP doesn't want to hear the opinion I have to give.  Anybody finding this thread in the future, even in a more open frame of mind, will have moved on already.
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Bruce S

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Re: Are Using Monopole Towers Taboo?
« Reply #32 on: June 01, 2011, 03:52:28 PM »
Couple items here folks.
Sparweb thanks for putting that up.
All others putting up the snide remarks back and forth.
How about we go back to posting the why's and wherefore's ?

If you want to snipe and snide each other there's the PM section for that.

Thanks
Bruce S
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