[TowerTalk] Equalizer plate dimensions

[David Aslin G3WGN]

Thanks Grant.
1) Yes, the tower is designed to be guyed.  I have the guy layout diagrams and the headload and windspeed ratings. All guys are shown anchored to a single point but there is no info about attachment to the ground.  What I have available is buried 2-ton concrete blocks with 10-ton breaking strain lifting chain attached.
2) You raise a valid point.  Do I need a fixed equalizer, pivoting equalizer or no equalizer?  Any experience or relevant engineering knowledge out there?
73, David G3WGN  M6O


-----Original Message-----
From: Grant Saviers [mailto:grants2 at pacbell.net] 
Sent: 02 August 2018 22:35
To: David Aslin G3WGN <david at aslinvc.com>; Tower Talk <towertalk at contesting.com>
Subject: Re: [TowerTalk] Equalizer plate dimensions

Two comments from my perspective,

1. Are you sure the crankup you have is designed for guys?  The UST crankups with guys have mechanical locks when each section is extended.  
They must be released to lower the tower.  The UST HDX-589 provided PE calcs and done by my PE show slim (IMO) safety margin in the hoist cable, so guying it above the bottom section would be a bad idea.  The sum of all the vertical components of guy tensions (9 guys for your
tower) plus the tower dead load must be within the cable and pulley assembly load capacities at the maximum rated wind speed.  A tall order IMO again.

2. Each tower is different but pivoting equalizers are not used on all towers.  The Rohn R65 concrete anchors guy attach plates are welded to the rods that go into the 4x6x2' buried concrete dead men.  In that case the rods are set at a specific angle w.r.t ground and each guy then pre-tensions equally.  There is little tension interaction since the plate can move only by bending the rod.  Not so with a pivoting equalizer.  It isn't clear to me why a pivoting equalizer is good for the tower in high winds.  Can other tower-talkians explain how?

Grant KZ1W

On 8/2/2018 13:43 PM, David Aslin G3WGN wrote:
> Hi Towertalkians,
> I have a pair of telescopic towers that are similar in size to a US Tower HDX-589.  The manufacturer specifies guying at 3 levels, but does not provide equalizer plates.  I'm mindful of the Towertalk prime directive, but as the manufacturer is no longer in business, I can't consult them on this topic.  Seems to me that equalizer plates are a wise precaution at this high wind location, but I'm open to the wisdom of the Towertalk crowd.
> In order to fabricate some 3-way equalizer plates I need dimensions of, for example, the Rohn equalizer plates.  Would any kind soul care to measure theirs or provide a specsheet that shows plate thickness, hole sizes and placements? The Rohn catalog is silent on the key points!
> 73, David G3WGN  M6O
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