Key takeaways
- An HMS carabiner is a pear-shaped locking carabiner with a wide, rounded top.
- It's designed for belaying, rappelling, and the Munter hitch.
- The wide end fits belay devices, knots, and multiple rope strands, and lets a Munter flip smoothly.
- 'HMS' is German for Munter-hitch belay (Halbmastwurfsicherung) — the standard belay carabiner.
German Halbmastwurfsicherung — 'Munter hitch belay'.
What an HMS carabiner is
An HMS carabiner is a pear-shaped (asymmetric) locking carabiner with a wide, rounded top, designed for belaying, rappelling, and use with the Munter hitch. The broad end fits belay devices, knots, and multiple strands of rope.
What HMS stands for
HMS comes from the German Halbmastwurfsicherung — ‘Munter hitch belay.’ The name reflects its origin: it was shaped with a wide, smooth pear form so the Munter hitch (a friction hitch used to belay or rappel directly on the carabiner) can flip back and forth smoothly as the rope direction changes.
Belaying a follower at an anchor, a climber clips their belay device into an HMS carabiner — the wide pear top giving room for the device and rope to sit cleanly — and knows that if they drop the device, they can belay with a Munter hitch on the same carabiner, which flips smoothly in its rounded top.
Why the pear shape is useful
The wide, rounded top accommodates a belay device with the rope, fits bulky knots and multiple strands, and gives a Munter hitch the smooth surface it needs to flip without jamming. That versatility makes the HMS the go-to locking carabiner for belaying and rappelling.
The bottom line
An HMS carabiner is the standard belay carabiner: a pear-shaped locker whose wide, rounded top fits belay devices, bulky knots, and multiple rope strands, and lets a Munter hitch flip smoothly. The name is German for 'Munter hitch belay,' reflecting that origin. If you belay or rappel, a pear-shaped HMS locker is the carabiner for the job.
Frequently asked questions
What is an HMS carabiner?
An HMS carabiner is a pear-shaped (asymmetric) locking carabiner with a wide, rounded top, designed specifically for belaying, rappelling, and using the Munter hitch. Its broad upper end gives room for belay devices, knots, and multiple rope strands, making it the standard choice for the belay/rappel connection.
What does HMS stand for?
HMS comes from the German word Halbmastwurfsicherung, which means 'Munter hitch belay' (literally 'half clove hitch belaying'). The name reflects the carabiner's origin: it was designed with a wide, smooth, pear shape so the Munter hitch — a friction hitch used to belay or rappel directly on the carabiner — can flip back and forth smoothly as the rope direction changes.
Why is the pear shape useful?
The wide, rounded top accommodates a belay device along with the rope, fits bulky knots and multiple strands, and provides the smooth, broad surface a Munter hitch needs to flip without jamming. This versatility is why HMS carabiners are the go-to locking carabiner for belaying and rappelling, and why most climbers carry at least one or two.
Sources
- Carabiners & belaying — American Alpine Club
- Equipment standards — UIAA