On Kurt's website he makes the following observation referring to a tower that is mounted on a pier with the equivalent of a ball socket mount: "Putting the tower on a free base connection has allowe
Hi All, Just to clarify a few things.... I think there may be potential for a bit of confusion about what various people mean when refering to "a pier pin" base. The text referred to here, was in the
There has been a lot of speculation that the downward forces on the base plate would prevent rotation about a pier pin. I know of one example where I'm sure there was enough torque to rotate about a
Makes me wonder if his guys were properly tensioned. Barry -- Barry Kutner, W2UP Internet: w2up@mindspring.com Newtown, PA FRC alternate: barry@w2up.wells.com List Sponsor: Are you thinking about ins
Seems to me that inserting a sheet of some engineering plastic material with a relatively low coefficient of friction between the bottom plate and the top of the concrete base might facilitate this s
Okay - I'll bite. What are the reasons? Cheers, Steve K7LXC Tower Tech List Sponsor: Are you thinking about installing a tower this summer? Call us for information on our fabulous Trylon Titan self-s
IF the Rohn flat plate were strong enough, one could simply place a small spacer, like a large nut, around the pin & under the plate. So the obvious solution would be to beef up the Rohn plate to an
As K3KO just pointed out to me, one might be concerned about the ability of the concrete base to support all that force and friction at one small point. A second thick plate, under the nut, should ta
Yes, a finger of his hand went into the open internal space of the tower leg that was encased in concrete. Yes, the TOWER Leg. The tower rotated, shearing off all three legs at the top of the concret
<< First, they use a flat bottom plate on the concrete. I doubt that these rotate at all to relieve the moment at the bottom.>> "The wide footprint on the pier may allow the tower to rotate about the
As Hank pointed out, both bases are pinned in a strict sense. The moment I was referring to is not developed by any fixivity to the footing, but by not having all three legs sharing the axial load. I
I mig weld 2"x1"x 3/16 thk square steel tubing from the outside edge of the plate under each leg (short side flat on the plate) to the center hole, with two pieces side by side under each leg. I wel
Hi Steve and All, The larger towers in the Rohn commercial catalogue use only a tapered base section and a bearing plate between the tower and footing that is machined so it has a small diamaeter und
Thank you folks! Interesting comments. A good summary of concerns regarding my original question can be found at: http://www.qth.com/ka9fox/pier_pin_vs_embedded_base.txt This was referred to me by an
Hi folks, I've seen quite a few installations being planned here starting out with the botton section of tower sunk in concrete. What I'm curious about is why a pier pin isn't used? On all my towers
There is a very full summary of the pros and cons of both systems on KA9FOX's web site. 73, Pete N4ZR No, no ... that's WEST Virginia List Sponsor: Are you thinking about installing a tower this summ
Agreed. It's cheaper, and it makes it much easier to plumb the tower. I've done three installations this way. My only concern has been to get the surface of the concrete base as nearly level as poss
Yes, a pier pin is a good choice and has been reported to allow for higher loads than a rigid (in concrete) base. But is it really Cheaper? Isn't the cost of base plate about the same as a straight s
Not quite but close, when I bought mine. Of course, if you have to move a tower all you leave behind is the pier pin. When I was looking into the choice, one knowledgeable engineer-type commented tha
on Huh? With 670# tension on the top 1/4" guys and 400# tension on the bottom 3/16" ones, how does the tower rotate? Can you actually see it move? I suggest that your guy tension is too low if you ca