[TowerTalk] Using Mastrant rope guying Rohn 45

[Lux, Jim]

On 7/31/23 10:01 AM, Tom Hellem wrote:
> Mark-
> The Rohn book specifies guying at 3 levels for 100' of R45.
> Top guy called out at 1/4" EHS, and other two at 3/16" EHS.
> I think you could safely assume that if you used Mastrant product equal in
> working load capacity to the EHS you would be OK. I would definitely defer
> to the
> tower erection experts on this group, though.
> Don't know about deterioration from sunlight, weather, etc.
> And I sure wouldn't use it at the bottom end where it would be subject to
> damage
> from critters, humans, fires, etc.
> FWIW.
>
> Tom
> K0SN
>
> On Mon, Jul 31, 2023 at 6:19 AM Mpridesti via TowerTalk <
> towertalk at contesting.com> wrote:
>
>> Anyone here have experience using the heavy duty Mastrant rope and all the
>> necessary accessories for guying a Rohn tower to 100 ft?
>>
>> Looking at the M-type rope perhaps 8-10-12 mm size.
>>
>> Regards,
>>
>> Mark, K1RX


I would want to do some analysis (or have someone analyze) the effect of 
the rope being much stretchier.  Failure load isn't the only thing. If 
nothing else, stretchier will change the distribution of loads among the 
guys, relative to steel.  With multiple guys, it's potentially a complex 
analysis (because the tower bends too) - N7LV had some nice analyses, 
maybe one could pull the model from that and run it with different guy 
properties.  His website is archived somewhere, and I believe he used 
GRAPE as the tool.

Wind induced vibrations might also be an issue (different mass/length 
and stiffness).  You don't want to be inadvertently building a 100 foot 
aeolian harp.