Locking carabiners are an integral part of the climbers kit. In this post we are going to take a close look at the notable differences in styles, shapes, and mechanisms along with making suggestions as to where in the climbing system certain models are best suited for both convenience and greater security.

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Screwgate Locking Carabiners

The most common style of locking carabiner is the traditional screwgate. This style has a “sleeve” on the gate that can be twisted until the sleeve is over a potion of the carabiner reducing the chance of the gate opening in any situation. A common error for beginning climbers is to screw this sleeve to tightly when locking the carabiner and finding it difficult to unscrew after the carabiner has seen load. Best practice is to simply screw the sleeve to where it stops easily turning then stop. Do not give it that “extra” turn. Then perform a quick “squeeze” test to verify the carabiner is locked. These carabiners are suitable for any use in the climbing system from belaying and anchoring to creating a top-rope master point. I prefer a screwgate as my personal anchor carabiner while multi-pitch climbing since auto-locking styles do not facilitate tying a clove-hitch on to the carabiner as smoothly as a screwgate that you can leave unlocked until you want to lock it. You can see that process in this quick video:

I also think a pair of the Petzl Attaches is the best choice for a top-rope master point and I carry two dedicated to this use. The reason these excel at this use is Petzl designed some grooves in the sleeve that interlock with the forged ribs of a reverse and opposed Petzl Attache. When used in this configuration the slightest of load basically eliminates the ability for these carabiners to unlock by vibration or even intentional hands. If you’ve ever arrived at a top-rope anchor to discover a locking carabiner has become unlocked during your session you’ll appreciate this added security feature in addition to the more well known “unlocked” red indicator, a nice visual clue that the carabiner is not locked.

Another screw gate carabiner I carry is the Petzl OK Locking Carabiner.  This carabiner is in a symmetrical oval shape which makes it ideal for use in both aid climbing and big wall climbing with the Petzl Ascension Handled Ascender. For improvised rescue (both multi-pitch trad and glacier travel) it pairs perfectly with the Petzl Tibloc. For use in a self-belay top-rope system (or a more robust rescue system) it pairs perfectly with the Petzl Micro Traxion Pulley pictured above.

I do carry one larger Petzl William Locking Carabiner shown above which has a few advantages over the smaller locking carabiners I have already mentioned. If I need to lower someone with a Munter-Hitch the wider “rope end” shape of the carabiner offers smoother lowering even when using thicker ropes. There are also some situations where a large locking carabiner can make a convenient easy-to-use “master-point” at the anchor when climbing in parties of 3 or more. I also find this carabiner to be a convenient way of keeping my quick-draws and alpine draws organized before or after the climb.

One final thought on screwgate carabiners… it has been noted that these mechanisms can be less prone to “gunking up” in dirty environments. For ice climbing I have not found them to be less prone to getting iced up then any other style of carabiner. See the maintenance section near the end of this post for tips on prevention.

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Twist Lock Carabiners

The next style we are going to look at is a locking mechanism that requires some care to be safely used. Twist Lock carabiners have a spring loaded sleeve that self-rotates into the locked position when the gate is closed. The advantage is the carabiner locks itself quickly. Popular models in this category are the Black Diamond Twistlock Carabiner, the Petzl Am’D Locking Carabiner and the Petzl Sm’D Locking Carabiner (both available in other locking styles). There is potentially less security in this style in the event of moving rope or a wrongly clipped belay loop that could press across the locked gate unlocking and opening it in an alarming fashion. This is best shown in a quick video clip:

 

While there are not many documented cases of this style failing there are a few incidents where this style might have contributed to a climber becoming disconnected from their rope system. Details are sparse enough that it could be fairly considered rumor. Regardless these carabiners are best used within the climbing system where there will not be moving rope going through them and their position can be monitored to ensure no unintended “unlocks”.

Some examples of where I would discourage their use:

• Rappelling with a tube style (Black Diamond ATC/Petzl Verso) device. It is conceivable that the carabiner could rotate into a position where either the climbing rope or the belay loop of the harness could press against the spring loaded sleeve in a manner that could cause it to open like demonstrated in the video above.
• Anchoring in on multi-pitch climbs, especially if in a larger climbing party. For starters it is a little less smooth tying a clove-hitch on to the carabiner when the carabiner looks itself when ever the gate closes. Also any moving rope, cordage, or slings above your anchor carabiner run a risk, however small, of passing over the gate in a potential fashion to open the gate.

Some examples of where they would be appropriate:

• Rappelling with a figure-8 style device. While not very common in rock climbing circles these devices are still preferred for caving, spelunking, canyoneering, and rescue. The difference between this and a plate style device is the moving rope does not pass through the carabiner greatly reducing the chance of it coming into any contact with the gate. Care should still be used when loading the system that the belay loop is not twisted and the carabiner is in position to be loaded properly along its main axis.
• Belaying with a brake assisting device like the Petzl GriGri2 or GriGri+. Since the climbing rope does not go through the carabiner with these devices the risk of unintended opening is almost nil. Care should still be used when loading the system that the belay loop is not twisted and the carabiner is in position to be loaded properly along its main axis.
• Added security at static points in a climbing system. For example to secure one leg of a multi-leg static top-rope anchor. Once the system is set up and loaded there is virtually no risk of anything coming in contact with the sleeve. Essentially Twist Lock carabiners are best used in places where they will not be exposed to much moving material.

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Triple Action Locking Carabiners

This category offers a fair amount of extra security over Twist Lock carabiners. While there are some variations within this category essentially a Triple Action carabiner requires three “actions” to unlock and open. In comparison it could be argued a Twist Lock under the right (or wrong) circumstances only requires one action to unlock and open (see video above). Popular styles include:

Petzl William Locking Carabiner: Available in Ball-Lock and Tri-Act Lock

Petzl Am’D Locking Carabiner: Available in Ball-Lock and Tri-Act Lock

Petzl Sm’D Locking Carabiner: Available in Ball-Lock and Tri-Act Lock

Petzl OK Locking Carabiner: Available in Ball-Lock and Tri-Act Lock

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Let’s look at the main difference between Petzl’s two Triple Action options. The following is from Petzl.com:

BALL-LOCK

ERGONOMICS

Advantages:

• Rapid auto-locking

• Visual locking indicator

Disadvantages:

• Sleeve must be unlocked each time the carabiner is opened

• Tricky sleeve operation, especially with gloves, requires practice. System is less “ambidextrous” than the others

• Two hands needed to insert a device into the carabiner

SAFETY

Advantages: 

• Security of triple action locking (excluding rubbing and external pressure)

• Rapid auto-locking

Risks:

• Chance of improper locking when the carabiner closes (e.g. sling caught between the nose and the gate). The user must verify that the carabiner is properly closed and locked, even when using an auto-locking system

TRIACT-LOCK

ERGONOMICS

Advantages:

• Rapid auto-locking.

Disadvantages:

• Sleeve must be unlocked each time the carabiner is opened

• Tricky sleeve operation, requires practice

• Two hands needed to insert a device into the carabiner

SAFETY

Advantages:

• Security of triple action locking (excluding rubbing and external pressure)

• Rapid auto-locking

Risks:

• Chance of improper locking when the carabiner closes (e.g. sling caught between the nose and the gate). The user must verify that the carabiner is properly closed and locked, even when using an auto-locking system

• Sensitivity to mud or other foreign objects that can impede auto-locking

This style of carabiner is an excellent choice for dedicated belay/rappel carabiners, plate style belay devices, and brake assisting devices like the Petzl GriGri2 and GriGri+ (review here).

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Some other Triple Action options

DMM Big Boa HMS Carabiner: Available in “Locksafe” option

DMM Aero HMS Carabiner: Available in “Locksafe” option

DMM Rhino Carabiner: Available in “Locksafe” option

Mad Rock Hulk HMS Carabiner: Available in “Triple Lock”

CAMP USA Guide XL Carabiner: Available in “3Lock”

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Magnetic Auto-Locking Carabiners

While a small category in the industry this is my most favored style of auto-locking carabiner. Namely the Black Diamond RockLock Magnetron Carabiner. This innovative style uses a magnetic system to lock the carabiner the moment the gate shuts. To unlock the carabiner one must pinch both sides of the gate. This motion is quickly mastered with either hand making this a very easy style to operate (yet next to impossible to create a scenario where the rope or a belay loop could mimic this pinch). After three winters of use I’ve had no issues with the mechanism getting iced up. Essentially I find these to be the fastest and most secure option in two places in my climbing system. First I use one for my main belay/rappel carabiner. Zero chance of forgetting to lock this important attachment and while it seems trivial the few seconds saved at every transition can add up. Second I use two on my plaquette style belay device.

Pictured here is my KONG GiGi but the popular Petzl Reverso 4 and Black Diamond ATC Guide would be a common substitute. Since some may ask about the GiGi I’ll add here that I typically am guiding with two clients so often I belay two ropes simultaneously. This can trash a guide’s elbows and shoulders over decades of yarding up rope and the Kong GiGi helps by having less resistance when pulling slack. I do also carry a Petzl Reverso 4 for rappels and as a “back-up” should anyone drop their belay device on a multi-pitch climb.

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Maintenance

Depending on the environment you climb in you may need to do some light maintenance to keep your locking carabiners functioning properly. In the Northeast I don’t find my locking carabiners needing much attention and probably give them a tune up every 3-5 years if they haven’t incurred enough wear to be retired. Climbing in soft dusty deserts might require a more regular maintenance cycle. Luckily it isn’t that hard. If a gate or sleeve is sticking or feels “gritty” wash the carabiner in a warm soapy wash. An old toothbrush can help if they are really gunked up. Rinse well. Apply a quality lube like Metolius Cam Lube. I’ve also had great results with Teflon based bike lubricants. DO NOT use WD-40 as this spray really attracts dust and dirt and you’ll find yourself back in the kitchen sink pretty quickly.

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My Kit

After reading all this you might be wondering how many locking carabiners I carry. I see quite a few newer climber carrying an excess of locking carabiners on their harnesses. If you think carefully about your climbing system you can streamline it which will help make you a more efficient all-around climber. Here’s exactly what I carry for multi-pitch traditional or alpine climbing:

Black Diamond RockLock Magnetron Carabiner paired with my Petzl Reverso 4

Black Diamond VaporLock and RockLock paired with my Kong GiGi

Petzl Attache dedicated to being my anchor carabiner, doubles as my third-hand back-up during rappels

Petzl William Locking Carabiner for racking my draws, munter-hitches, master-points

If we will be top-roping I add two Petzl Attaches per top-rope system I’m setting up.

So that’s only 5 locking carabiners with specific jobs for multi-pitch climbing and another 2 for top-roping. As always if you find yourself short a locking carabiner somewhere you feel you need one you can use two non-locking carabiners with gates reversed and opposed.

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Related

Tying a Clove-Hitch on the Carabiner

Tying a Munter-Hitch on the Carabiner

Gear for Top-Roping

Improved Belay Checks

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Summary/Giveaway

Hopefully this post has been informative and will help you optimize the amount and style of locking carabiners you spend your money on. There are so many options out there these days and it is helpful to recognize where one style may more more convenient, or even more secure, than another style. Drop a comment below on anything related to this post and your name will be entered into a drawing for a brand new Petzl Am’D BallLock Carabiner! Drawing will be held on October 31st at 12 PM EST and winner announce here and contacted via email.

See you in the mountains,

Northeast Alpine Start

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