Lattice Tower Questions

[brokengun]

I am currently working on putting up a 7 foot diameter homemade turbine. A 30 foot lattice tower was donated to me by a local airport. I've read a lot about putting up towers made from pipe with a jin pole design but I'm not sure that is best for this tower. The tower is triangular and each side is about 16 inches long, it is pretty sturdy and I expect it to have no problem with my size windmill.

I was thinking about putting a hinge on two of the feet and then using a jin pole to get the rest of it in the air. Once the tower was upright, we would put the third foot into a hole and put a bolt through it. This would take some construction.

My other option is to just put some pins in the concrete base and stack on each new section as it comes. I would have to use a crane or a scissor lift or something but it could be done. I am just worried about the machine over-speeding or getting trashed to bits in high winds if we can't take the tower down in a short period of time.

Does anyone have experience with smaller lattice towers like mine? What method did you find works best to put it up both for safety and easy of construction.

Thanks!

[jonas302]

a story with some pics

http://www.fieldlines.com/story/2008/8/1/22321/42776

try google search for tiltover towers there are a few interesting ones

[scoraigwind]

If you like climbing, and you can be safe, then bolting this tower onto a big concrete base is the best way to go and then climb up and work at the top.  But if you want to tilt a tower down then a guyed waterpipe is the lightest and simplest.  Then you stay at ground level which is dull dull but  much easier and probably a safer place to be.  If it doesn't fall on you.  First time you put it up on its own without the turbine.  Make sure the guys at the sides are the right tension throughout the lift.  Correct placement of anchors is important there.  Use a gin pole at right angles to the tower to minimise the strain on things.

As for stopping the turbine in strong winds, you can usually do this easily with a short circuit.

If you plan to work at the top of a fixed lattice tower with heavy parts then a small temporary pole up there with a pulley on top is handy for lifting parts into place.  Wear a harness and tie yourself on and make sure nobody walks around below you.  Best to have a second pulley at the base of the tower also, and pass the rope through that and away to the person(s) who pulls if you have one/some in a safe place.

have fun but watch out!

[Reno]

Hinge the bottom and then run a cable to another vertical structure like a pole or strong tree. Then you are pull from the top of the opwer and the cable is supporting the tower so it will not buckle. Same as a gin pole put there no need to design an attachment point.

I use an existing pole, connect the pulley to the top then cable back down to the tower mid way up (equal the height up the pole) then winch it up.

[Rover]

I have a derrick rigged tower, meaning that there is a center pole. It is about 30'  high with about a 4 x 4 footprint. My base (concrete is a must), extends down about 3' , tappering from the outside to the inside. I estimate3 I have roughly a 1 1/2 tons of ballast below the tower (20 80 lb bags). I have two 6" conrete filled pipes ( about 3' above surfece, and need really to be about 8') that sandwich the main 2" center pipe. I have a 3/4" rod going through the 6" pipe and the center pipe, acting as an axle. I can lower the entire tower with a 1700 lbs 12v winch when needed but not for the faint hearted (which is why I need my lever to start at 8 ft, rather than 3 ft).   ..

hope this helps,

Rover

[zenpi314]

Hi Rover,

Do you have pictures of this setup?

I'm working on something similar.

Zenpi314

[Ungrounded Lightning Rod]

If you want to make a tilt-up out of a lattice tower you may need to make a base for it to brace the three legs to a constant spacing.  In a normal installation the tower may get this bracing from the ground mount.

Look at the bottom:  If it doesn't have a really solid triangle of three horizontal cross-braces just above the base joint you'll want to provide that bracing by mounting the tower on a hinged base, rather than hinging two of the tower's legs.

(You may want to do the hinged base anyhow, even if it does have the cross-bracing.  The stresses on the tower that is raised with its full load installed are worse when tilting it up than when it's in place.  So you don't want to have the structure of its base support flakier when raising it than when it's up unless you have a tower that's far overstrong for the load, giving you a big safety margin to whittle away.)

[Rover]

Yep, I'll try to post some today

[Rover]

Here ya go, I will be raising my pivot point to 8', however by removing some of the front lattice work I can bring her down now. The winch bolts down to the concrete in front of the tower and connects to the center pole.

The legs are on raised concrete with rebar. The tower itself uses 3/4" galv pipe for the legs and 1/8" steel for the lattice for the legs. The legs tie back to the center pole 5 times

[Shadow]

I have two tilt over lattice towers using this gin pole method. It takes about 15 minutes to raise or lower. More pics in my files.

[Rover]

now that is a nice looking tower