As usual, I'm coming in late on a discussion of a lot of good points about skinny rope. Here is a picture of use of small diameter line in a recreational situation, that is not covered by ANSI. Due to bulk, half inch rope does not work in this single rope technique (SRT) application because it is a 400' length, carried across steep country and hoisted with a throwline over 150'-200' high limbs. But we're here to talk about arborists.
The authorities feel arborists should read Z133. It mandates 1/2" rope with the exception that smaller diameter rope may be used in SRT techniques and in climbing situations when it can be demonstrated that it doesn't pose a hazard to the climber. It also requires the rope to be a minimum 5,000 lb. test.
The split references in the two categories--standards & definitions, and the distinction between Standard Operating Procedure and exceptions, make it harder for me to absorb. I do need to catch up on the intent & letter of the law.
My state's OSHA organization has adopted ANSI, making it, in effect, a law. My job is to comply,
in my opinion, not whine about someone else telling me about how to do my job. The ANSI committees are not someone else, the members are arborists who have stepped up to the plate, while I go steppin' out. I thank them for tackling this task for our safety & productivity.
I was a tech for the last two ITCC competitions: in Milwaukee on the Belayed Speed Climb, and here in Seattle on the Throwline events. This limited experience has given me a glimpse of the role of the governing bodies. The interaction of these two committees (ANSI & ITCC) seems to have a tremendous cumulative impact on what happens out in the field.
With the introduction of 'FLY' rope, things will be heating up in regard to use of smaller diameter rope by arborists. This was illustrated at the post gear-inspection meeting of the ITCC committee in Seattle. The discussion centered around Mark Chisholm's use of Fly rope. I didn't understand how the distinction of its use in the qualifying events was made from its use in the Masters Challenge. Or how rope-type restriction in the footlock or aerial rescue event would encourage homogeniety among the competitors scores.
A point was made that it was Mark alone that was using Fly; it may have been a fairness issue since it may have been a prototype, rather than a production item, and therefore, unavailable to the other climbers. The reference to it meeting the specifications of ANSI was moot--the ITCC committee stated their decision to approve or reject a tool supercedes that of ANSI for the purposes of the competition.
The manufacturers specs say specifically that it is designed for arborists use in particular. The entire manufacturers statement was read at this meeting for clarity (so it would be entered into the minutes of the meeting, I spose). This last criteria seemed to be what became the crux-that the manufacturer would assume the ultimate product liability, since it has deeper pockets than the ISA.
One other official regulation that may provide some insight into the relationship between grip strength and rope diameter is that of the timber sports sanctioning body, the U. S. Axeman's Association. The lanyard used in the pole climb event must be of a very large diameter (
at least 7/8", with a steel core), for the purpose of the hand being able to grip it. Can you imagine how cumbersome our lives would be if we had to use fatter ropes, not thinner?
Arboreally yours,