Tower Question

[wind4Reg]

I was thinking that a tower that hinged in the middle might be a good idea. Perhaps a hydraulic piston could be used to operate the hinging. So for any servicing the tower would basically fold in half and the top of the tower would be upside down at ground height. If you ever had to climb the tower you would only have to climb half way up. Does this sound possible or has anyone attempted or built something like this?

[SparWeb]

Only about a month ago, someone was writing on this forum about a Rohn fold-over tower.  Try searching for that...  I think a drawing was posted, too (bonus!)

[SmoggyTurnip]

Follow this link for some nice hinged towers:

http://www.northeastwindenergy.com/index.html

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[Hoskald]

This is all I could find on the fold-over Rohns on the board.

http://www.fieldlines.com/story/2006/6/12/141627/117

Hos

[jimovonz]

Why complicate things with hydraulics etc? If the tower pivots in the middle then why not extend the top section down past the pivot point for a nice big lever to lower/raise it using a rope?

[antw]

I'm not sure if I have asked this before but how far into the ground do the two side posts go, and how much concrete (if any) do they have around them?

[asheets]

When my father was a teen and digging post holes for the REA for spending cash, the perscribed depth was 1 foot down for every 2 foot exposed.

[jimovonz]

The 8m side poles are 2m into the ground. The pole in the middle is 10m. The engineer at the local lines company told me that a standard 8m power pole embeded 2m into the ground was rated for a 6kN lateral load at the top. This seems a lot to me and I think his specs relate to a guyed pole (probably using the standard screw anchor). I have three guy wires/screw anchors on this pole and I don't think anything short of a  hurricane is gonna move it. I've tited it up/down by myself with over 200Kg on the end with no drama (used a come-a-long and a 200l drum filled with water on the short end as ballast)

[Walt]

If I remember a 30 footer is set 6 feet deep and a 40 is set 8 feet in the ground. Hope is helps.

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[Ungrounded Lightning Rod]

GREAT!

Instead of a hoist, use a water pump to fill the bucket when it's up until just overbalances, and a block-and-tackle to let it up gently.  Jack it DOWN by prefilling the bucket then siphoning water out until it just goes the other way.  Meanwhile the bottom of the tilt-up serves as a counterweight so you only need to lift the difference in weight, not the whole thing.

(Won't work on a tilt-up with a gin-pole, though.  Would run away once you got it off the dime.  I'll have to look into whether there's a way to fix that...)

[Ungrounded Lightning Rod]

What are you using as a pivot?

How did you get the swing pole up initially?

[jimovonz]

The pivot is a 40mm steel rod drilled through all three poles with large wasahers and pins on the end.. As for putting it up, my mates 20 tonne excavator comes in handy... I think it would be quite a job to do by hand!

[wind4Reg]

Why complicate things with hydraulics? Because I don't have a buddy with a 20 ton excavator to put it up for me. I need to be able to do this easily, preferable by having just me remove the safety pins/latches and then push a button and watch it lower or raise. I suspect the simple hydraulic power units from a car hoist would do the trick.

[thefinis]

While I am a big fan of hydraulics having played with it most of my life on the farm I don't quite see how this will make it easy. Your tower will have to be safety pinned on the side opposite from the hinge to be safe as a hydraulic piston isn't safe to use as a holding support. You would need to climb half way up to pull pins and put them back.

I think that hinging at ground level would actually be a better way but would require more engineering and heavier duty construction. If by car hoist you mean a car jack for changing tires then no I don't think that will work. Since you say push a button I am thinking of one of the units like operate a lift gate on a truck and yes that might work with the right valving, cylinder and holding tank.

The hinged with counterbalance sure looks nice. If you want to push a button a good 12 volt winch should work well with it and is probably cheaper than hydraulics plus being more portable. I know I keep looking for a good enough reason to buy one that will convince the wife.

How do you plan on building the tower as that would help give more of an idea on how to do this?

Finis

[jimovonz]

I have seen a number of lattice towers with a single support that hinge in a similar fashion. I only used poles because I worked in forestry (and had a friend with large machinery . The poles would have cost me around $US1500 alone so obviously not an option for everyone. It was the counterbalanced pivot concept I was suggesting, not the use of large heavy poles.

[thefinis]

They have a pic of a hinged counterbalanced tower that looks to be hydraulicly lowered and raised. Here is the link: http://www.northeastwindenergy.com/towers.html

Finis