There are a few mental tools that we use when we instruct people how to climb safer and better. One of these is the use of acronyms to remember the components of safe anchor systems. Fortunately, these are becoming part of the average climber's vocabulary. The two that are most commonly used are SERENE and ERNEST. Here's what they stand for:
Solid (or strong)
Solid (or strong)
Both of these acronyms have the basic components that make a safe, reliable climbing anchor. I'll go over each component individually:
Solid. This means that each individual piece that makes the anchor (i.e., nuts, cams, ice screws, pins) are solid enough on their own. See Jason's 12/4 post on "The 12-Point Anchor System" for a great way to quantify how solid pieces are. Ideally, you want multiple pieces that are all capable of holding a significant fall.
Redundant. There should be more than one piece for the anchor. Common anchor examples are two bolts, three pieces of rock gear, etc. One exception is a single rock or tree - the BFT (Big freakin' tree) and the BFR (Big freakin' rock) - that can be counted as sufficiently reliable on its own.
Equalized. Each piece in the anchor should share the load of the anchor force equally. If there is slack to any single piece, that means that that piece is not loaded, and the anchor is not equalized.
No Extension. This means that if one piece should blow out of the anchor (and become useless), there will not be a shock-loading of the anchor as a result. If there is slack to one piece and the others blow out, there will be a severe load directed onto that piece - a shock loading. Prevent against this. Note that the "Magic X," also known as a "self-equalizing anchor" must have load limiting knots to prevent shock loading.
Timely or Efficient. These terms relate to the common adage "speed is safety." While speed is not the only important element, it is quite important to make your anchors in a timely manner. If it takes 20 minutes to make an anchor, that can add up to a LOT of time on a long multi-pitch route. The faster you can make an excellent anchor the better. Absolutely take the time you need to make a good anchor, though, a quick but weak anchor is no good!
SERENE and ERNEST are basically equivalent. Some climbing schools teach it one way, and some the other way. I'm sure there are other anchor acronyms out there, but these are the two that stick in my head the best. Hopefully they can help you when you are assessing your own anchors on your next climb!
--Mike Pond, Instructor and Guide