I’m setting up a bunch of lowering stations on sport routes. I’m a cheap-assed do-it-yourselfer. What type of chain should I use for my rig?
—Buddakahn via rockandice.com
For some folks, the mere thought of using hardware-store chain for a life-or-death application is a laxative as natural and effective as a large bowl of
steamed prunes. To be clear, however, we are not even thinking about the dinky metal braid you’d use to stake out Fido and Fifi. We are only talking
about industrial-strength, welded chain, the stuff they use at tractor pulls and to subdue Jeffrey Dahmer types.
Carbon steel, 5/16-inch Grade 30 chain, which you can get at the hardware store, is the anchor-maker’s stock in trade. This size chain has links large
enough to clip, and will accept a 5/16-inch locking quick link, which you can use to attach the chain to the bolt hanger. Ace/True Value and their
zombie clones charge $6/foot for the chain and they don’t even have the courtesy to use lube. Order it for $1.20/foot (plus shipping) from tulsachain.com.
For those of you who fret that two pieces of welded steel chain will break before cancer or a car wreck gets you, relax. Grade 30 5/16- inch chain has
a typical breaking strength of 7,600 pounds. Erring on the side of caution (and why not?), you can purchase Grade 43 high test for $1.33/foot.
This chain has a breaking strength of 11,700 pounds.* To compare, most carabiners break between 5,000 and 6,000 pounds, and most 3/8-inch bolts including
the Power Stud and the Power Bolt, have breaking strengths of 4,000 to 7,000 pounds.
In a typical anchor situation where the bolts are no more than a foot apart and level with one another, I use four chain links per bolt, and attach the
chain to the hanger with a quick link. On the rope-clip end, I use regular aluminum carabiners, but steel biners would last longer and I intend to
use them just as soon as I find the lost treasure of Jesse James up at the crag.
5/16-inch chain has nine links in a foot, so you can buy 12 inches, cut out the middle link and get two pieces, or one station’s worth of chain, for each
foot of chain. Be warned, however, that cutting steel chain requires a … chain cutter! (Make the bot at Ace/True Value chop it up for you—they
love it when you buy lots of chain, four links at a time.) Using four chain links per bolt makes the entire system, counting the quick link and the
carabiner, about a foot long. This lets the bottom carabiners touch as long as the bolts are no more than 12 inches apart, and minimizes rope twisting
when you lower. Cost for the chain and links is about $8 per anchor. Add $3 for the hangers, $3 for the bolts and $12 for the carabiners, and the station’s
total sets you back $26.
The weak link in this system is the quick link. This has a working load limit of 1,760 pounds and a breaking strength of just under 6,000 pounds.
This might seem adequate until you read the label, which says, “Do not use to support human weight.” What’s up with that?
It could be that lawyers with experience in the tobacco industry wrote that to keep their clients from assuming any responsibility for any action including
(but not limited to) intentionally or unintentionally crippling or killing you. Or the tag could mean exactly what it says. If this bothers
you, get the brand Maillon Rapide ($10), which is meant for personal safety, or use carabiners to attach the chain to the hanger. Next!
* Note: Chain and quick links are labeled with a Safe Working Limit (SWL) or Working Load Limit (WLL). This is different from the Breaking Strength rating that you see on climbing gear. The Working Load Limit is typically 1/3 a product’s breaking strength. By industrial manufacturing standards, Breaking Strength is the average force at which the product has been found by representative testing to break under controlled laboratory conditions, and is not included on the product labels. For this article I use only Breaking Strength, which you can research online by product, since that is how climbing-gear strengths are presented.
This article was published in Rock and Ice issue 207 (January 2013).