Fabricator,
I'd like to make a few more comments regarding your tower situation.
I just got a quote from exmork that I can get a fifty foot tilt up monopole shipped to either Chicago or Detroit for a little over 4300 bux, that is not too bad
Is it a hydraulically operated tilt-up? Hope you checked to see what is included. I suspect that for that price they include the tower, the hydraulic cylinder (if its a hydrauluic tilt-up tower), the hydraulic cylinder base plate, the fourteen 1 1/4 diameter 89 inch long foundation bolts, and two "positioning boards" (mine were made out of ten pound plate). On mine, those cylinders are huge compound cylinders weighing about 400 pounds apiece, look like they fell off a D-10 CAT ripper. They cost $990, in China. If all that stuff isn't included, you need to shop some more, because that cylinder and those bolts will cost you boo-koo bucks here in the states.
Also, if the tower you got the quote on is rated for 10 kw turbines, as mine are, and you're only going to put a 5 kw turbine on it, you can add a bunch of height to it. Those towers are designed to withstand a certain amount of rotor thrust; turbine weight isn't the determining factor. If you're going to add to it, I'll be happy to run the calculations for you, but you should probably have them wet-stamped by an P.E. licensed in Michigan so they got somebody to sue if it comes down, which it won't.
Check out this website:
http:www.f-n.cn
It is for the Shenzhou Hangzhou tower company, the folks that built my towers. You can download a tower installation manual from that website. The manual gives all the structural specifications for their towers, dimensions, steel thickness, flange diameters, etc. I suspect they make towers for exmork, because when I asked exmork if they could send me a hydraulic tower, they referred me to that website above. You can verify this by asking exmork to email a tower manual to you, and comparing specs. If they are the same, you will be getting a well built tower. Or you can just ask James Ye if Shenzhou makes their towers.
according to Poco they are built very heavily and the exmork guy said they are hot dip galvanized
Just for fun, download the Skystream tower manual and compare it to the Shenzhou tower. Either the Skystream tower is way underbuilt (which I seriously doubt) or the Shenzhou is overbuilt. And yes, mine are hot-dipped. I think they leave them in the tank too long; never in my life have I ever seen such thick galvanizing. I had to grind some off to do some welding, and the zinc looked like it was about a sixteenth of an inch thick.
In case you can't tell, I really like my towers. It takes me less than a minute to remove the 22 one inch diameter flange bolts using an air impact wrench, then my Kubota tractor lowers the tower from full vertical to full horizontal in 25 seconds. Takes 45 seconds to raise it back up to full vertical. The cylinder and the hinge hold it while I put the bolts in. The Chinese even supplied a huge drift to align the bolt holes; crude but effective. I wouldn't even think of using any other type of tower, and without those towers I'm not sure I'd want any wind turbines. They'll spoil you rotten too.
You might also check with Pilot86, or maybe he will chime in here, but he recently bought a hydraulic tower and I think he got it directly from Shenzhou. He told me he had it shipped into Boston for less than $3 grand, cylinder and all. And by the way, he was having problems with the authorities too. Don't know if or how he resolved them.
poco