GWG wrote:Rick,
The quick links that are found at the anchors, are these the standard quick links you find at your local Home Depot store? If not, where do you get the ones you are using?
It would be nice to have a few of these available to donate to the cause whenever I head down and climb there.
Geoff
These quicklinks are better quality than the stuff found at big box stores. They are from MacMaster Carr (part # 8947T18), and you probably cannot buy from them unless you have a business account. They are $1.82 each in quantities of 100. Their cross section is 3/8 inch, and they have a working load limit (WLL) rating of 2200 pounds. That is about 10 kiloNewtons.
Now, here's where a lot of confusion occurs.
It is important here to clarify some very important terms. I believe all climbers should know these differences. There is a big difference between WORKING LOAD LIMIT (WLL) AND ULTIMATE STRENGTH ratings.
The ultimate strength ratings for climbing gear exist to give you information about the limitations of the equipment. Without exception, the strength rating of all climbing gear indicates the maximum load the gear endured prior to destructive failure using standard testing procedures. Under no circumstances should strength ratings be interpreted as a safe working load value. For example, a FIXE ring anchor has a strength rating of 26 kiloNewtons. At this load the piece is a hair breadth away from total failure.
Now, the quicklink that I referred to earlier does not come with an ultimate strength rating, but rather a working load limit rating (WLL) of 2200 pounds (about 9.7 kiloNewtons.) This quicklink will ultimately fail at a significantly higher load -- a value that the supplier does not provide. It is probably rated somewhere in the neighborhood of gear made by Petzl, Fixe, and others. Read "probably."
The term safe working load, (SWL) was the cornerstone of engineering, particularly with regard to load carrying equipment, for many years. It was generally considered to be the breaking load of a component divided by an appropriate factor of safety giving a ‘safe’ load that could be lifted or be carried.
About 20 years ago, however, the U.S. ceased using this term, because of legal implications. The European and ISO Standards followed suit a few years later. However, while this was a clean-cut move, for some time there has been indecision as to exactly what replacement terms could be used.
Over the past few years, both the Americans and Europeans have agreed that working load limit (WLL) should replace safe working load (SWL) in describing the capacity of items such as hooks, slings and shackles etc.
A general definition of WLL was: "the maximum mass or force which a product is authorized to support in general service when the pull is applied in-line, unless noted otherwise, with respect to the centreline of the product."
So, where are we going with all this technobabble?
The bottom line: The quicklink I referred to above is not offered by its manufacturer to hold up human beings. The Fixe, Petzl, etc. gear IS offered to hold up human beings, and is therefore much more expensive.
YOU, and you alone, must judge the safety of the hardware you are hanging from. This information is provided to you so that you can better understand the ratings and decide accordingly.
Most of the chains and quicklinks found on anchors in the Red are NOT designed specifically for human loads. Most of the 3/8-inch, grade 40 hardware store chain you see on anchors down here has a working load rating of about 5400 pounds. Because you shouldn't be taking a fall (dynamic load) on an top anchor system, you should be mostly concerned about the static load applied. The ratings on these chains and quicklinks seem to indicate that they should be able to sustain very high static loads. But, again, you must be the ultimate judge and be willing to accept responsibility for the risk you are taking in this crazy sport.
Finally, remember that in many cases, this Corbin Sandstone stuff we flail around on will blow out long before any hardware will fail. The rock itself is, indeed, the weakest link in many cases.
Rick