[TowerTalk] LOOKING FOR A USED CRANK UP SELFSUPPORTINGTUBULARTOWER
w8car at buckeye-express.com
Wed Feb 1 13:54:21 EST 2006
My US tower anchor bolts which were installed about a year ago had two nots
locked against each other threaded onto the bottom of the straight rod and
the thread end was 'peaned' over. No welding in effect.
----- Original Message -----
From: "darrel" <darrel at vanbuer.net>
To: <rmoodyg at bellsouth.net>
Cc: <towertalk at contesting.com>
Sent: Wednesday, February 01, 2006 12:37 PM
Subject: Re: [TowerTalk] LOOKING FOR A USED CRANK UP
> It also shows straight bolts on their foundation drawings.
> But they DO have a nut and washer welded? on the end to keep it embedded.
> I have no idea whether epoxying a straight rod into a drilled hole has the
> same pullout resistance as a J-bolt or nut and washer (it's not enough
> the epoxy is stronger than concrete - it's adhesion to the bolt is
> critical -
> rebar is bumpy so that the concrete gets a good grip), but a couple of
> bolts do take the entire uplift force on the upwind side with a 70 foot
> lever arm (rough estimate 20,000 pounds per bolt, a good fraction of it's
> breaking strength).
> My guess (but I have no structural qualifications), is that the J bolt
> washered straight bolt) snaps long before you could pulverize enough
> to pull it out.
> As to the change - I'd guess the found the price of J bolts higher than
> current choice and either way pullout wasn't the first failure.
> Darrel AK6I
> --- "Richard M. Gillingham" <rmoodyg at bellsouth.net> wrote:
>> They're shipping straight bolts now. I just received mine a couple of
>> Gil, W1RG
>> ----- Original Message -----
>> From: "Jim McDonald" <jim at n7us.net>
>> To: <towertalk at contesting.com>
>> Sent: Wednesday, February 01, 2006 11:31 AM
>> Subject: Re: [TowerTalk] LOOKING FOR A USED CRANK UP SELF
>> > Doesn't US Tower require J-bolts, rather than straight bolts?
>> > Jim N7US
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