A critical skill to master and practice before a mountaineering trip is building a secure anchor. While we don’t anticipate needing them often on our spring expedition, sturdy anchors are crucial when rappelling, protecting yourself while crossing a dangerous slope, and when performing crevasse rescue. Because we will be on a glacier, almost all of our protection will use snow or ice for construction. This gives us several options for types of anchors:
Snow picket: one of the easiest and fastest anchors to place is a snow picket, given the right snow conditions. It is essentially a large T-shaped tent stake that can be driven vertically into the snow as a reliable anchor. However, for a picket to be a good anchor when placed vertically, the snow must be firm enough for you to hammer the stake into the snow; if the picket can be placed vertically by only using your hand or foot, it is better to place it horizontally (deadman anchor explained below). To effectively place a vertical snow picket, hold the picket 90 degrees to the slope with the pointed end of the picket facing downhill, then tip it another 15 degrees upslope and hammer it in. Drive the picket into the snow until the top hole is level with the snow surface or until the picket won’t go any deeper (must go further than halfway in). Place the carabiner that will connect to the weighted object in the hole closest to the snow surface, and voila! A quick and sturdy anchor.
Fluke: another tool that helps build a quick anchor is a snow fluke. It performs best when used in wet and heavy snow, and when placed correctly, will actually dive deeper into the snow when weighted. When incorrectly placed, however, it is easy for it to be deflected and pull out of the snow. To correctly place a snow fluke, the picket needs to enter the snow pointed about 45 degrees below parallel to the slope with both wires taught and the load coming from straight out in front of the fluke. If the fluke is tipped too far forward or back, the load is not lined up correctly, or one of the cables gets caught on a hard snow layer and is no longer straight, the fluke can be pulled out of the snow when loaded. For this reason, they are best used in a uniform yet heavy snowpack.
Deadmen: these are great anchors because you can use almost anything to build them; pickets, backpack, ice axe, stuff sack filled with snow…rumor has it you can even use something as small as a snickers bar if the snow is firm and you bury it deep enough. To build a deadman anchor, first imagine where the direction of pull will be coming from; the anchor will be buried uphill and perpendicular to that direction. Dig a trench big enough to fit your item and about one and a half feet deep, as well as T-slot for the runner. Place a girth hitch around the deadman with a sling, place it in the bottom of the trench, run the sling through the slot (make sure the T-slot is deep enough to reach where the sling leaves the deadman), and then fill in the trench and the slot with the uphill snow. A few tips to make your deadman anchor even better:
Especially when the snow is light, it helps to “work-harden” the snow between the anchor and the weighted object. To work-harden the snow, stomp on about three square feet of snow below where the trench is.
For a picket or an ice axe, it helps to undercut the bottom of the trench and help nestle the deadman into the work-hardened snow so it doesn’t get pulled back out the top of the trench.
Once you have decided on which type of anchor you will be using, it is helpful to follow the acronym ERNEST when evaluating your anchor:
Equalized: build two anchors that distribute the weight of the load equally between the two.
Redundant: always be redundant when building an anchor system; instead of counting on just one anchor to hold the load, build two solid anchor points…or even better, build three. Be certain to place the two (or three) anchors that are to be connected as close together as possible without overlapping. As the angle between the slings of the anchors increases, the amount of force exerted on each anchor also increases.
No Extension: in the event that one of the anchors in your system fails, make sure the other anchor doesn’t suddenly extend. This could not only cause harm to a person that is hanging from the anchor, but also puts a sudden and large amount of force on the remaining components of the anchor system that may cause them to fail as well.
Solid: make sure every piece of the system is as stable as possible (knots, carabiners, deadmen, etc)
Timely: while it is important to have a solid anchor, you should be able to build them in a timely manner. If you are building an anchor for crevasse rescue, minutes may matter to the person on the end of the rope.
And lastly, always double-check your system and safely test it before going over the edge! Once you weight the anchor(s), you will quickly see where the system can be improved.