Ice Screw Placement on Multi-Pitch Climbs
by Michael Powers, IFMGA
AAI Senior Guide & Director for Staff Development
From the April 2008 edition of AAI's E-newsletter
On a multi-pitch ice route, when would the lead climber place a directional ice screw for an upward pull? Would you also explain why one piece as a directional may be is placed instead of two or three pieces like in an anchor scenario? Also, is it ever appropriate or safe to tie a sling directly to an ice screw hanger in lieu of clipping a carabiner in the ice screw hanger and attaching the sling to the carabiner?
- Lisa Jensen (Boulder, CO)
Generally, ice screws are multi-directional in that if placed horizontally, they also hold for an upward pull in addition to the downward pull. However, because the weight of the belaying climber is sufficient to hold an upward pull on the anchor, it's rare that I protect anchors specifically for upward pulls. There are a few exceptions. For example, when the weight difference of the lead climber and the belayer is substantial I might protect specifically for an upward pull. Or, if there are features on the route that with an upward pull might force the belayer to loose control of the belay (brake) strand of the rope, I might also design an anchor that protects an upward pull.
One reason that only one screw may be used for a multi-directional placement, (if indeed it is placed at all) is that the upward force is generally smaller. This occurs because the belayer's body weight is already in the system holding the screw down. However, there may be times when you are belaying a leader off the anchor (and not off your harness) when a multi-screw placement would be more suitable that a single screw placement.
It is important to note that each ice climb has its own objective hazards, like falling ice and rock. For this reason, it's impossible to generalize about the extra time and effort needed to place more screws at anchors.
Personally, I don't think I have ever placed an extra additional ice screw at an anchor solely for the purpose of protecting for an upward fall -- since the ice screw is already somewhat multi-directional and the risk of an strong upward pull can be reduced in other ways.
You also asked if it is appropriate to clip a sling into a screw hanger as opposed to using a biner. Generally I would say no. The screw hanger is somewhat sharp and will reduce the strength of the sling. Also, it is slower to set up and break down if you are not using a biner. However, it is possible to tie a sling into a screw hanger -- I would only do that if I could justify it somehow. For example, I might tie a sling if I was out of biners and had no other choice, or if I was belaying off my harness and the load placed on the anchor were minimal.
- Mike Powers
Click the link to return to "Ask A Guide" Letters.