[TowerTalk] J Bolt Specifications

[k7lxc at aol.com]

> I have started digging the hole for installation of a used US Tower MA-40 with MARB Rotor Base. I contacted US Tower for a quote on four 3/4" X 27" anchor bolts but they say that is not a stocked item so lead time is 6 - 8 weeks.

>  If I wait 8 weeks to get the bolts then 28 days for the concrete to cure that means 3 months before I can get the 3 element SteppIR in the air.

>  Do any of you structual engineer guys out there know what specification J bolt is needed and a good source. Shipping will be to northern California.
>  I said J Bolt but I know US Tower is now welding two nuts and a washer to the end of the 27 " bolt. Don't know if that is a structual improvemet over a J bolt or just easier to manufacturer.
     Google a steel supplier and check on what's available elsewhere. You only need threads on one end of the rods - 8-12 inches should do it. Even if you have to have the rods threaded, it'll still be cheaper and faster than UST.
 
    You don't need a J-bolt. Just weld some nuts or pieces of metal to the bottom of the rods and you'll be good to go. The J or nutted bolts do the same thing - they add some more resistance to them pulling out.

    When you pour the concrete, use 4kpsi instead of the spec'ed 3kpsi. It'll cure up to 2-3kpsi in a couple of days and then you can install the MARB, etc. That should cut a couple of months off of your project!
Cheers & GL,Steve       K7LXCTOWER TECH -Professional tower services for amateur and commercial