----- Original Message -----
From: "Bill Aycock" <billaycock@centurytel.net>
To: "Bill Winkis" <kc4pe@mindspring.com>
Sent: Tuesday, November 17, 2009 1:22 PM
Subject: Re: [TowerTalk] Cable working load/breaking strength...///
> Bill-
> If you re-read this from AMTEC carefully, they are not saying that they
> recommend a safety factor of 10. They used it as an example. Admitted, it
> gives that impression. It would be interesting to pin them down to a
> number. Such a selection should be a variable, dependant on the
> characteristics of the application, and not on their insurance rate.
> Bill--W4BSG
>
> ----- Original Message -----
> From: "Bill Winkis" <kc4pe@mindspring.com>
> To: <noddy1211@sbcglobal.net>; <KJ6Y@aol.com>
> Cc: <KJ6Y@aol.com>; <towertalk@contesting.com>; <jimlux@earthlink.net>;
> "Bill Winkis" <kc4pe@bellsouth.net>
> Sent: Tuesday, November 17, 2009 12:54 PM
> Subject: Re: [TowerTalk] Cable working load/breaking strength...///
>
>
>> *Here is what the folks at Amtec are saying... I use there cable grips...
>> *
>>
>> *The broad application of AMTEC Grips on a wide variety of objects
>> requires that adequate safety factors be used to establish a safe
>> working load. The ratio of the listed approximate breaking strength to
>> the normal working load is the safety factor. As an example, a safety
>> factor of ten (10) would then mean that the working load is established
>> by dividing the catalog listed approximate breaking strength by ten
>> (10), or it can be stated that the working load is 1/10 of the catalog
>> listed approximate breaking strength.*
>>
>> *Now read below....
>> *
>>
>>>> *My blueprint of my LM70 clearly states that the pull/down cable shall
>>>> be
>>>> ..3/16..7X19 and have a WORKING LOAD of 1400 pounds....most cable sold
>>>> advertise a BREAKING STRENGTH ... the best I have found is 4200
>>>> pounds....or a working load of 420 pounds..a far cry from the 1400
>>>> pounds asked for on my print...
>>>>
>>>> As above....I am told the Working Load is 1/10th of the Breaking
>>>> Strength...
>>>>
>>>> If this is true ..where in the world can you find a 3/16 cable with a
>>>> breaking strength of 14,000 pounds..???
>>>>
>>>> Or am I missing something....*
>>
>>>> * -Bill*
>>>>
>>
>>>
>>>
>>> Maybe you're thinking of guy tensioning recommendations: 1/10th of rated
>>> capacity?
>>>
>>> For a hoist application, the mfr may have different recommendations.
>>> Engineering such things is a bit different (what design factors do you
>>> use for where the cable runs over a sheave or pulley? what about dead
>>> weight vs live weight.)
>>>
>>> Maybe LXC's directive is applicable here.. ask the mfr what they mean.
>>>
>>>
>>> _______________________________________________
>>>
>>>
>>>
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>>>
>>>
>>>
>>
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>>
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>
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