tilt up towers

[halfcrazy]

I am looking to build a tilt up tower in the 80-100 ft range. i have read thru everything on here i can find and still have a question or two. i have seen a few people using a boat winch and drill motor to raise and lower them are they using a block and tackle afair? any one got some pics maybe? the other question i had was if i can find say 4 inch light wieght tubing in 21 ft lengths what would be the best way to join them? thanks for the time on this at 100 ft dont want my new 10 footer to came crashing down

[wooferhound]

Here is a lot of information I found about Tilt Up Towers . . .

http://www.otherpower.com/otherpower_wind_towers.html

http://www.fieldlines.com/story/2005/8/7/225917/1540

http://www.fieldlines.com/story/2004/9/24/212132/415

http://www.fieldlines.com/story/2003/11/8/21428/8811

http://www.fieldlines.com/story/2003/6/7/10635/15909

That should give you about 18 ideas on how to do it !!

[halfcrazy]

thanks wooferhound i had read all but one of those the winch is what has me the most confused i noted that dan had chains on his truck to raise his seems like that little boat winch woulndt handle it unless there where a block and tackle afair?

[BruceDownunder]

100 foot is a bit scary if you don't do it right.

I am just finishing my 57 footer off and at 42 feet it was comfortable,but that 15 feet more really makes it bendy and more rigging (a lot) is required . My steel is heavy angle , bolted back to back.

Now, 60 foot steel pipe (3 1/2 to 4 inch) is common guyed at 20 foot intervals, and lifted with a ginpole of at least 20 feet long .

100 feet would require a possibly 5 to 6 inch pipe and a ginpole of some 35 feet. Big stuff you are getting into now-1/2 inch wire winch rope ,3-4 ton winch , 4:1 block and tackles; swaged wire rope ends-man thats radio station transmitter stuff.

Could be wrong ,but as a licenced rigger from way back in my radio station days ,towers of this size require professional engineering

"You only get one chance"

end of lecture...

bruce

[BruceDownunder]

I'll see how smart I am with posting some pic's -don't hold your breath---Bruce

[wpowokal]

80-100' is a serious tower that requires some careful concideration of your wind conditions, rotor diamiter and tower design.

Guy radius is critical as is spacing particually the upper half.

I had some heavy walled boiler tube machined down to fit into the tower pipe but left 2" full diamiter to weld lugs to.

I also use an endless winch, very controlled.

http://shop.btcv.org.uk/shop/level2/8/level

Tower hogging during raising and lowering can be a big problem with tall small diamiter towers. Having said that 4" is probally doable.

I can take pics of joiners and winch if required, pics of 80' tower failure in my photos.

allan down under

[halfcrazy]

thanks for all the info i will give you a better idea of my sight i am in a small clearing surrounded by 60 ish foot trees as soon as the sun shines again we are going to get a exact hieght of the 2 tallest ones. i am guessing 80ft will take care of me but will see i had two different ideas on the tower the first is to go with schedule 40 tubing and start with say 4.5id for 20ft then 4id for 20 then 3.5 then 3 then 2.5 with guys at every connection. the second was going with lightwieght 4 inch tubing the hole way. my other possibility is going with a lattice tower i have access to a crain for a small fee to stand a lattice tower just that you have to climb it anytime you need to get to genny. thanks again for the pics and info i have 3-4 months to think on this. i just ordered my mags and rotor discs will start fabbing the yaw bearing and tail bearing today. and for watever its worth i have a civil engineer as a brother in law so could run any questionables by him???

[wpowokal]

Bad idea keep the same size all the way, greate forces on top sections.

allan down under

[halfcrazy]

thanks allan will do any opinion of the wall thickness would you go with a 4 or 5 inch thin wall tubing?

[wpowokal]

I am not a structual enginere so can only speek fom my experience. Anything over 60' I would use at least 5", as to wall thickness, larger diamiter can have thiner walls as strength is in cross sectional area.

My commercial tilt tower by Synergy is 90mm(3.5") OD with very thin walls, is 58' tall with 4 sets of guy wires, it has a 2.8m rotor on top. The blades are fiberglass with the generator casing being aluiminuim, so not a lot of weight. IT has a "boat winch" which is easy to use, BUT it has no ratcheting when lowering, so don't let go.

Hogging during raising and lowering was something I was unaware of until it happened to me. Guy radius is more critical as height increases, never less than 50% tower height and for a 100' tower, well I would have to do the maths but at a guess 65-70%.

 The reasons are to do with the bending moments around each guy attachment point. If you were able to attach the guy wire to a sky hook such that they were at 90 deg. to the tower it would never go any where, but in reality we can not.

The blade diamiter has a large bearing on what you can get away with inyour tower. Gin pole length also becomes a pain for heigh towers as idealy it should be near on the radius of the anchor point.

80' of spagetti......

Allan down under

[picmacmillan]

half crazy, i can give you a couple of points from an engineering standpoint. first, some basice engineering facts to help you decide what you want to do..

 1) what you're doing is complex. go to a local college or university and get someone who is a 3rd or 4th year mechanical, or structural engineer, and they will help you free of charge to build this system. I could help you , so could others, but it would take forever here. there is way too many variables to get it done properly.

 2)things to take into consideration. yeild strengths, ultimate yield strengths,modulus of elasticity, equilibrium, mass moment of inertia, bending moments, and plenty of others.(not something the average joe can handle)

 3)dont use threaded rod to join the pipe( of any diameter), it may work for now, but the threads make the pipe weak. the center(mass moment of inertia), of a triangle that is created using the tower to the guy wire is 1/3rd from the biggest side. this is just a couple of small things to consider, ....i had a hand in building a control tower at an international airport once, and it wasnt as tall as your tower will be...if you can do it, my hats off to you...as stated above, anyone who has current experience in applied engineering could handle this job, it is just a static load, until the genny starts turning, and then we have a different beast altogether, and the forces change. i am optimistic that with the right people, it can be done, but without knowing what materials you have to work with, or what a tower that size would require to be solid,is something that would have to be disclosed while you are drawing up the system....good luck, if you get it done, it would certainly be a good thing for alot of folks here, . we would all like to be up where there is good air....pickster

[halfcrazy]

ok after reading all this and reading extensively bergey offers a 80 ft kit and a 100 ft kit both use 4.5 in thin wall tubing in 10 ft sections. so basing it on that i am thinking about 4 inch thin wall tubing(readily available)still not shure on joining them maybe a special 3-4 ft sleave of proper diameter and weld everything as we go? bergey uses a shorter jin pole then i was thinking any down side to a longer jin pole? my sight really dictates a 80 ft tower the tree line seems to be in the 65 ft range. i could go with a lattice tower and guy it but then i have to climb the sucker for any maintnence? i will say money isnt going to be a factor i wont skimp on the tower i will do what it takes to put the genny in the air right to the best of my ability.keep the opinions and suggestions coming i want this to go smoothely and i do have a licensed engineer in the family so can run my final draft by him thanks again just started welding on the genny today should have my magnets and stuff soon will start a diary of pics and stuff

[wpowokal]

Halfcrazy what size unit is going on top ie balde diamiter and weight?

allan

[halfcrazy]

i am building a 10 ft machine based on dans plans

[wpowokal]

Halfcrazy, For my money an 80' tower is doable with 4" pipe for a 10' rotor, of course with 21' lengths it will become 84'. My failure had a number of contributing factors, but Murphy just kept hitting me over the head until I arrived at an excellent 10' duel rotor on 60' tower.

Do not skimp on the number of guy wires and have wide anchor points. It is critical to have the top anchor points closer than the lower ones because their angle causes much of the load to be transfered  to the next section down. And if its too far to the next anchor point it can bend.

Pickster is quite correct in his comment but there are ways of determining what will and will not work without the maths. Of course your local authority may insist on an engineres aproval, but then you have one on tap.

This thread will soon vanish over the edge so 'e' mail me if I can help awh35544(put the cymble in here)bigpond.net.au

allan down under

[bduser]

I am new to the board, but I have a Bergey XL.1 on a 104' tilt up tower.  It is really a very simple setup.  The base just sets on the ground with a couple of ground rods to hold it in place.  It is guyed every 20'.  The anchors are 5' long and "screw" into the ground.  The tubing looks like electrical conduit with a bell ( 8" - 12" ) that slips over the lower section. The guy wires attach to a stamped plate that slips down to the bell.  Only the top 4' section is attached with screws.  The whole tower is designed to be flexible.  The guy wires are not tensioned like a rigid lattice tower would need.  The gin pole for mine tower is 30'.  I use a block to get 2:1 and go real slow. I can take a couple of pictures of anything you might have a question about.  We have some turbulent winds here on the Colorado plains and the tower does move!  It has been up a little over 5 years with out problems.

[halfcrazy]

bduser thanks for the info i read all the info on the tilt up stuff of bergey's and was leaning towards there tower but i think with some help and guidance i can sorce local pipe and design it basically around bergeys how do you rais and lower it with a winch of some sort?thats what i am real curius about

[bduser]

I use a mid-sized skid loader, 773 Bobcat.  The low range of a heavy truck would work.  Anything that can go "real slow" and no sudden starts or stops. A bigger tracter, I wouldn't use my Allis Chamler WD. I have seen a heavy duty "boat winch" used, and that is a bit too slow.

One end of the cable goes is attached to the anchor just past the end of the gin pole. Next the cable goes through a pulley on the end of the gin pole and back to a pulley on the anchor.  The other end of the cable is attached to the bobcat.  I can double check tomorrow.  There is a poly rope that goes from the gin pole to the two anchors on the sides to steady the gin pole.  You want to make sure all the hardware is rated for the weight you have. A good farm supply store is a good bet.

Did you pick up from the docs how the guy wires are brought from the anchor to the end of the gin pole? That can be tense if a breeze comes up. It only takes about 5 minutes to lower or raise the tower, but I spend an hour double checking everything before hand.  Also, always do a dry run first with your new tower.