In the process of doing some recent tower work I learned something about
carabiners that I didn't know before. This may be common knowledge to many
here, but worth passing along nonetheless.
I recently purchased a handful of Black Diamond Ovals from the climbing
department of REI to replace some lost over the years. A couple of them had
the manufacturer's instructions stapled to them. Buried in the fine print is
the sentence: "Carabiners are stamped with a strength rating that describes
their failure load -- the force under which the carabiner will break when it
is properly loaded." Guess my simple mind figured that the rating stamped on
a device like this would be the **safe working limit** not the point at
which it fails. Seems to be a departure from how some other devices we use
are labeled, but given how they are used in climbing this makes sense.
Complicating matters is the fact that they are rated in force (mass x
acceleration) with units of kilonewtons. One kN is about 225 lb-force.
If you do any tower work and don't own a half dozen of these you don't know
what you are missing. They are extremely handy and some of the non-locking
variety are only about $6 each. Just don't use the type that are intended
for key chains that can be found at checkout lanes of the big box stores.
They aren't rated for loads.
BTW, the pronunciation of the word is kar-uh-bee-ner (with the accent on the
"bee"). The word has French and German origins from the words meaning
"carbine hook", as they were used to attach carbines to bandoleers. Probably
more than you ever wanted to know.
Larry Burke K5RK
Brazoria County Texas
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