Tower Time

[windspeed]

I would like to know if the following is good practice

my goal is a 40 ft tower for a 17 or 20 ft genny, I want to arrive there in two stages

stage one is to erect a 20 ft tower with a 10 ft genny on top with the four anchors placed at 25 ft radius (to suit 40 ft guying)

the first stage tower of 20 ft is 3 1/2" internal thin wall pipe

when I go to stage two this will make the top half of the 40 ft tower

I would appreciate any ideas on gin pole length and winch anchors, tower pivot attachment

also guy ring and eyes

and stepping down to accept yaw tube

much appreciated

[wpowokal]

Tower questions are dificult to be specific on as there are many site variables as well as litergation lunatics.

But to your questions, 25' radius for a 40' tower would suit, the greater the distance the stronger the tower will ultimatly be. The most importand guys are the tops two sets and they ironically have the most acute angel rendering them least effective of all sets.

The pipe you mention I would be happy using for a 10' unit but definatly no a 17-20' unit.

Gin pole length should be just less than guy radius for easiest errection, draw your tower to scale on graph paper, draw in the guy wires then a line from base to a point about 3' above indicated ground as your gin pole and measure the length. Using this arangement allows the guy wires to remain connected to the gin pole and you then anchor the gin pole. I use light steel cable from mid point of gin pole to each side anchor, this stops the gin pole from bending sideways during raising and lowering. (Back anchor is the one the tower is lowered towards, front is the pull up or gin pole anchor)

Anchor points is a grey area because your ground(soil type frost etc) and wind conditions are not known. Tower to gin pole piviot look at DanB 17' artical and copy his arangement.

Stepping to yaw tube, I achieve by welding a plate to the tower top, another to the bottom of the yaw tube and bolt the two together.

I cement in 2" galv angle as anchor point and atach to that with a "D" shackle- turnbuckle-"d" shackle-cable with 3 cable grips. Tower side I weld pieces of 1 1/2" flat bar with holes drilled in for "D" shackle, use thimbles on the steel cable. The tower base must have a line of site through the piviot point to the guy wire anchor point for each side anchor. This keeps side cables in correct tension during raising and lowering, oh and when you get that far tie the turnbuckles so they can not rattle undone.

allan down under

[windspeed]

thanks for your comment

i intend using the 3 1/2" pipe on the upper half of my planned 40 ft tower in stage 2

cant quite get your explanation of the anchored gin pole (good plan )

can you explain

 "Gin pole length should be just less than guy radius for easiest errection, draw your tower to scale on graph paper, draw in the guy wires then a line from base to a point about 3' above indicated ground as your gin pole and measure the length. Using this arangement allows the guy wires to remain connected to the gin pole "

thanks again

windspeed

[wpowokal]

Perhaps a pic will help

allan down under

[windspeed]

is the gin pole not at 90 degrees to the tower

does the gin pole stay off the ground all the time

windspeed

[wpowokal]

The gin pole is not at 90 deg. I do sugest not less than 80 deg because when the tower is lowered it is necessary to hold tension on the gin pole or it will go "over centre" and lay down on the tower then you need a gin pole to raise the gin pole. Can explain if required but trust me millions don't.

It stays off the ground as showen in the pic, how much is not critical just a matter of what is practical and suits you.

Follow this link to Bergey some good info,

http://www.bergey.com/Products/XL1.Tilt.IM.4.pdf

Please keep asking question if necessary.

allan down under

[windspeed]

what is the detail at the joint between gin pole and tower that allows it to lay down on top of the tower when lowered

if the gin guys are shorter radius than the others how does it affect stability

and how much is allowed

windspeed

[alancorey]

Take a look at http://www.otherpower.com/otherpower_wind_towers.html which might help.  At least there are pictures.

> that allows it to lay down on top of the tower

I don't think it does.  Gin pole seems to be a very generic term.  This is the third sort of gin pole I've heard of.  One being a smaller tower just slightly over 1/2 height of the main one, another being a pole about 1-1/2 times the height of a section of Rohn-type tower that you hook onto what's currently the top section for hauling the next one up.  This type seems to attach near the base at almost a right angle and just stay there if it's not in the way.

The link above is on our hosts' site.  There's a lot of good stuff, but some is hard to find.  Here's another page: http://www.otherpower.com/otherpower_wind.html

  Alan

[wpowokal]

OK as usual I have caused confusion, not hard for me. If you made your base as showen by Dan's the gin pole could no lay down, the way I do it it can. So some pics may help.