Ropes for climbing are each certified for 1, 2, or 3 different designations. Each of these designations requires passing separate tests. Knowing your ropes is key to climbing big routes on rock, snow, or ice. When teaching clinics for the American Alpine Club Craggin’ Classics, we hear many questions about ropes. Here’s one that recently came up on Mountain Project:
Q: I have climbed on routes in a team of 3 people where there is a traverse. I sometimes clip both half ropes into the protection to prevent a large pendulum fall for both of the followers. Does this increase the force on the gear I have placed? Could this be a problem if there isn’t a lot of rope out in the belay and I have marginal gear only rated to 5-6kn?
A: If you are clipping a marginal or small piece of protection with half ropes, but want to have both ropes attached to the piece to help prevent either follower’s pendulum, clip the two ropes with different length slings. For example, one rope could be clipped directly (or to a short runner) on the cam, and the other could be on an extended 60cm sling. Used in this way, a fall will only weight one of the two ropes (the one with less extension) which is the way half ropes are designed. To understand the extra forces produced with both ropes catching a fall, consider what would happen with a hypothetical 3 or 4 ropes clipped to a single piece. With each additional rope, the total rope stretch becomes less, the fall becomes more impactful, and the force on the gear is greater. In reality, most good protection clipped when you’re not just above a belay will withstand these forces, but it’s better to stack the deck in your favor when possible.
- Single Ropes are the standard for most climbing, and are designed to be used with just one rope clipped to all pieces of protection by the leader.
- Double Ropes (AKA Half Ropes) are designed to be used two in tandem, with the leader belayed on both ropes at once. However, each piece of protection is only clipped to one of the two ropes. Generally one of the two ropes is clipped to protection on the left side of the pitch, and the other is clipped to protection on the right. Clipping both ropes into a single piece of protection will put more force (and less rope stretch) on this piece of protection than the system is designed for, if a fall occurs onto this piece of gear.
- Twin Ropes are designed and tested to be used together when clipping all protection. Treat both strands as a single rope when leading, but clip in to belays by clove hitching yourself in to a powerpoint using either of the two strands you’ll be tied in to.