Wind tower base/ anchors

[Volvo farmer]

The backhoe guy is moving dirt around on my property. I need to build a base for a tilt-up ~40ft wind tower to fly a DanB 10' turbine. The tower will be built from 2 7/8" oilfield pipe. I chose a spot for the tower about 70' from my power shed and have an old Kenmore washing machine frame (baically a sheetmetal box that's open on the top and bottom) that I want to use for the base form. It's 36"(tall)x29"x28", so about a cubic yard of concrete. I told him to dig a hole for it and backfill it. Do you think this is enough concrete for a base? the soil here is very clay-like and 36" is deep enough here to avoid frost heave.

I'll need to do anchors for the guy wires as well. Can anyone help me lay these out? I have a lot more of these washing machine frames and could bury four more of them. I've also thought about trying to find some of those auger type anchors, which would be cheaper and easier than pouring 4 yards of concrete. If I do use the the washers, does a cubic yard buried at each anchor point sound like enough to take the wind stress on the wires?

I'm quite new to this tower building idea and could use some input here. I'm assuming that the top set of guy wires will be at about 30' on the tower so I'd want the anchors 30' from the base. Does this sound right?  Lastly, I should use 2 sets of guy wires for this thing right?  15' and 30' on the tower? and then anchor both of them about 30' away?

Sorry for all the questions but I can't think of a better place to ask then on this board. Thanks everyone.

[Victor]

 Assuming that the mill furls, what you have described is overkill (nothing wrong here except cost)

 A few points:

 With a 40' tower and a 10' diam. rotor I would place the top guys at 35' to minimize the moment and deflection. Just be sure to have them below the blade tips

 A 40' tower with a thirty foot guy radius is  conservative (nothing wrong here except taking up space, the extra cost of guys is insignificant.

 A guyed pole as you descibe is a soft structure and is usually "run" with somewhat loose guys.

Because of this, frost heave is normally not a concern. Many commercial towers in this size range are erected without any or with minimal concrete at the base. The only concern is the shear force when the tower is raised, I some times use a temperary cable to the far anchor to resist this force while pulling up the tower, if it is at all questionable .16" or so square will be plenty of bearing on the soil once it is up.

 A cubic yard at each guy is more than enough and allows you to have the top of the concrete flush with the ground. An anchor that was buried 3.5' to 4' could be 1/3 of this, however the rods bringing the anchor point to the suface then need to be galvinized.

Make the wind fun!

Aerofire Windpower

[Volvo farmer]

Victor, thanks for the information. That was very helpful.