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Re: [TowerTalk] Concrete in the ground! But...

To: <>, <>
Subject: Re: [TowerTalk] Concrete in the ground! But...
From: "Dick Green WC1M" <>
Date: Sat, 23 Sep 2006 10:36:55 -0400
List-post: <>
If the consensus is to bend the rod, then I'll try it by hand first. As for
the angle, we had a heck of a time lowering the downhill anchor much below
45 degrees. I think if we'd gone to spec, 42 degrees, the equalizer plate
would have ended up several inches below ground! Since that one came out at
45 degrees, we made the others the same.

Due to the steep slope of my hill, I couldn't make all three guys at all
three anchors match the Rohn specs for guy angles. The bottom guys on the
downhill anchor and the steepest uphill anchor are about 5 degrees off from
Rohn spec and about 10 degrees off from each other. In addition, I had to
place the anchors further out than Rohn spec to provide clearance for the
middle SteppIR. In the end, I made the angles for the top guys match each
other, figuring that was most important. The bottom angle for the top guys
came out at 45.9 degrees, so I figured a 45 degree rod angle would be OK.

73, Dick WC1M

> -----Original Message-----
> From: [] 
> Sent: Saturday, September 23, 2006 9:33 AM
> To:
> Cc:
> Subject: [TowerTalk] Concrete in the ground! But...
> GAC3455 anchor rods are not that heavy.  If it were me, I 
> would just bend the rod to the correct position by pushing on 
> it.  Also the anchor rods
> should be less than 45 degrees, more likely 41 degrees.   If I recall
> correctly, you only need about 5 yards of concrete for your 
> system, however the extra doesn't hurt anything except your wallet.
> GL,
> John KK9A
> To: "Tower" <>
> Subject: [TowerTalk] Concrete in the ground! But...
> From: "Dick Green WC1M" <>
> Reply-to:
> Date: Sat, 23 Sep 2006 01:16:29 -0400
> List-post: <>
> Hi all,
> At long last, the concrete is in the ground for my 110' Rohn 
> 55 tower! Whew, that was a lot of work. And a lot of concrete 
> -- 8 yards. I went with 4d anchor specs, which doubles the 
> hole size. Even then, we had some problems digging "small" 
> holes with an excavator and ran into some ledge and big 
> boulders. Took a lot of concrete to fix that. Some photos and 
> more details are posted on my website,, under 
> Big Tower Project.
> Here's the "But...". The base is level. All the anchors are 
> at 45 degrees and the equalizer plates are level. Two of the 
> anchors are pointing at the pier pin exactly on the compass 
> heading I had planned. But somehow one guy anchor is off 
> about five degrees or so in azimuth, so it doesn't point 
> directly at the pier pin. In fact, it points several feet to 
> one side of it.
> I'm pretty sure we had it right before the pour. It's 
> possible the rod shifted during the pour, but I checked it 
> several times and thought it was aimed OK. The last time I 
> checked it there was so much concrete in the hole I didn't 
> think the rod could move anymore. One possibility is that the 
> weight of the bucket loader we used to shuttle concrete to 
> the holes slightly shifted the ground around the anchor, 
> moving the whole section of earth and the anchor rod with it 
> (the bucket loader was positioned between the rod and tower, 
> fairly close to the rod.) Maybe the shift happened after I 
> checked the rod, when he dumped the last load of concrete. At 
> any rate, I didn't discover the angle error until the 
> concrete had set enough to prevent movement.
> For those of you wondering why the groove in the side of the 
> hole didn't hold the rod in place, this anchor is uphill from 
> the base. Consequently, the rod extends further above the 
> surface than it would on level ground, and only a very 
> shallow groove was needed to set the angle. Besides, if I'm 
> right about the effect of the bucket loader, a deeper groove 
> wouldn't have helped. BTW, the uphill rod in question is not 
> the one shown on my website.
> That one is OK. I'll post pictures of the rod in question 
> tomorrow if I get a chance.
> So, my question is... will 5-10 degrees of error in azimuth 
> cause problems?
> There's at least a yard and a half of concrete in that 
> 6'x3'x4' hole, maybe more. I don't think the slab is going 
> anywhere. Seems to me the anchor rod might bend a little. But 
> the GAC3455 rods are very beefy. Even if it bent a little, I 
> can't imagine it would be weakened enough to break. I'm using 
> 1/2"x12" eye-jaw turnbuckles. Could they be bent or damaged 
> by the angle error? Is this a problem, or am I just worrying 
> over nothing? Seems to me there's not a heck of lot I can do 
> about it at this point!
> 73, Dick WC1M


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