Carabiners are those handy little loops of aluminum used to clip things together. To those unfamiliar with the sport of climbing, the nomenclature around 'biners can be quite confusing. This little article explains some of those naming conventions.

Many Carabiners A = Large Autolock HMS B = Large Screwlock C = Mini HMS Screwlock D = Small Screwlock E = Medium Screwlock F = Medium Autolock

First, the name: Carabiner. In the USA, this is usually shortened to 'biner (pronounced bean-er). In the UK, it becomes crab.

Second is Locking vs. Non-locking (or regular). Locking biners have a metal or plastic sleeve that prevents the gate from opening. Why would we want the gate locked closed? Simple - when your life depends on it, a locking biner is used to MAKE SURE the carabiner stays closed, and those things that should be inside the carabiner stay inside. Things like the sling securing you to the cliff, or the rope you are rappelling on.

Locking Carabiners: A = Large HMS Autolock B = Mini HMS Screwgate C = Medium D-shaped Autolock D = Small D-shaped Screwgate

Climbers use non-locking carabiners for clipping the rope to protection pieces. Where climbers depend on one piece, such as clipping into a belay and for belaying and rappelling, they use locking carabiners.

In canyons, there is no real use for non-locking biners. Use a non-locking carabiner for anything you are willing to lose. Even hanging stuff on your harness with unlocked biners is hazardous - bumping against walls and downclimbing chimneys will often knock non-locking (and unlocked lockers) off your harness.

This article concentrates on locking carabiners ("lockers").

Autolock vs. Screwgate

There are two kinds of locking devices in common usage. An Autolock uses a spring of some kind to automatically close the locking sleeve. There are many variations on this theme, each company having its own design or designs. For the most part, the complex mechanism tends to clog up with the fine sand found in the desert, and Autolocking carabiners should be shunned by canyoneers.

Screwlock lockers use a simple threaded sleeve to lock the gate. The canyoneer must take the effort to spin the lock closed each time it is used. The simple mechanism of the screwgate resists clogging better than autolockers, but they still jam up on a regular basis.

Munter Hitch on a Mini HMS Screwgate

Belay Lockers vs. Utility Lockers

Lockers can be divided into two classes by how they are used. Belay Locking Carabiners are used for belaying and rappelling. While any locker can be used for these critical functions, a larger, rounder carabiner is easier to use and makes for faster travel.

In canyons, we use belay carabiners for rappelling and belaying, as well as for biner blocks and munter hitches. For ATC-type belay devices, it is handy to have two belay carabiners to put "under the device" for more friction. For adding friction while on rappel, a munter-hitch belay biner on the leg loop can be clipped through for added control. When really needing help, a munter hitch can be added on the leg loop.

For carabiner blocks, the larger diameter rod of the belay biner holds the clove hitch better.

Utility Locking Carabiners are useful for doing other things, like clipping yourself to an anchor or guide-line and clipping your pack below you when rappelling. For these functions, the greater size, weight and cost of a belay biner is not useful, so smaller, lighter carabiners can be used.

HMS vs. Non-HMS Belay Biner

Belay Biners come in two flavors:
HMS or Munter Hitch Biners and
Non-HMS or regular.

If you have not become friends with the Munter Hitch, perhaps you should. It is a handy knot to know for belaying and rappelling, and can be very handy in emergencies. Certain belay biners are designed with smooth lines to work better with the Munter Hitch - and are called Munter Hitch Biners, or "HMS" biners for short. HMS biners come in two sizes: full-size and mini. Of course, the "mini" size is still pretty big, basically "medium" on the general scale of carabiners.

To further complicate matters, HMS biners can be symmetric or assymetric. The symmetric ones are optimized for using the Munter Hitch, while the assymmetric are function-compromised to get a higher strength rating. Go for the symmetric - the extra strength rating is a marketing gimmick.
 

Now that you are fully versed in the arcane art of biner nomenclature, I can recommend exactly two types of carabiners for your canyoneering pursuits:

A: Symmetric mini-hms screwgate belay biner. Great for belaying, rappelling, munter hitches and biner blocks, the () is the basic workhorse of canyoneering. The Petzl Attache biner and the Trango Mini-HMS Screwgate are the best versions of this on the market. Carry at least four of these, perhaps as many as six.

B: Assymetric small screwgate utility biner. Light, inexpensive, small - something for clipping in stuff and not much else, it does not need to be fancy. The Black Diamond Quicksilver Screwgate is my favorite. Carry two to six of these.

Not-Carabiners

Before we conclude this discussion, we should discuss some things that look like carabiners, but are NOT. Little "toy carabiners" come with some waterbottles or may be purchased seperately.

They are called toys for a good reason, are NOT carabiners and should not be used in canyons, even for mundane tasks like holding your waterbottle or clipping off your pack. They are WEAK, WEAK I say: very, very weak and unpredictable. You may consider dropping your waterbottle while rappelling a minor inconvenience, but your former partner below might disagree. Did I mention always to wear a helmet?