【Deep Dive Essays】Rappelling: Practical Techniques and the Fight Against Human Error

Part 1: The Danger of Rappelling — Why So Many Accidents Happen

Rappelling in open air off Ichinokura Eboshi-iwa

What the Statistics Show

Rappelling is the single largest cause of death in climbing. Roughly 25% of climbing accidents occur during rappelling, and the fatality rate is extremely high.

The core risk is simple: failure almost always means a fatal fall. Because rappelling happens away from the anchor and often at height, any failure translates instantly into a fall with no margin for recovery.

The Reality of Human Error

Most accidents stem from human error. The main causes, along with real incidents, are as follows.

Anchor-related

• Anchor failure (insufficient strength, corrosion, misjudged rock quality)
• Poor anchor selection (overestimating the strength of dwarf pine, or haimatsu)
• 2019, Mt. Maehotaka: A climber used haimatsu as the sole anchor; it broke, resulting in a fatal fall.

Rope-related

• Two ropes not properly joined, causing them to pull apart
• 1999, Matsuki-zawa; 2004, Mt. Tanigawa; 2000s, Fudo-iwa: A poorly dressed figure-eight knot came undone, leading to a fatal fall.
• 2009, Nishi-Joshu (West Joshu): A climber failed to notice the ropes were uneven in length and began rappelling without tying off the ends (fortunately caught the error partway down).
• 2014, Futago-yama, Saitama: While rappelling a cliff longer than the 50m rope reached, the rope end slipped through the device, resulting in a fatal fall.
• 2019, Mexico: Renowned climber Brad Gobright died when the rope pulled through the device during a simultaneous rappel.
• Rope too short (the end doesn’t reach the ground)
• Forgetting to tie a stopper knot in the rope end (rope slipping through the device)

Device-related

• Device set up incorrectly (carabiner gate open, or the device loaded backward)
• Dropping the device
• Threading the rope through the self-belay carabiner by mistake

Other

• Clothing or a towel caught in the device
• Failing to clip a self-belay to the anchor
• Descending without a backup and letting go of the rope

What these causes have in common is that they’re all “small mistakes.” Even experienced climbers make them under fatigue, time pressure, bad weather, or simple haste.

People make mistakes. Risk management starts from that premise — building a system where one mistake doesn’t immediately mean a fatal fall.

Part 2: The Basic Sequence — Building in Certainty

The Standard Rappelling Sequence

1. Self-belay
Clip a self-belay to the anchor using a sling and carabiner. This is only removed once every step of setup is complete.

2. Thread the rope through the anchor
For a single rope, thread the midpoint through the anchor. For two ropes, join both ends with a double overhand knot (a standard overhand plus a stopper knot). A double fisherman’s bend also works, but watch closely for tying errors.

3. Flake and divide the rope
For a single rope, tie both ends together with a double overhand knot. Split the rope into two halves — the end side and the anchor side — and drape the end-side half around your neck. For two ropes, confirm which color you’ll pull to retrieve the rope.

4. Set the backup
Set a friction hitch (such as a Prusik or Klemheist) below the belay device. Use roughly a 7mm × 150cm cord, wrapped 3-4 times.

5. Set the belay device
Set the belay device at the midpoint of your lanyard. A device rated for direct belay is recommended.

6. Start the descent
Release the self-belay. One hand feeds the rope below the friction hitch, while the other hand releases the backup as you descend.

7. At the next anchor
On reaching the next anchor, clip in a self-belay immediately. Then pull the rope down and prepare for the next rappel.

Building Certainty Into the Sequence

Running through a checklist out loud is the key to a reliable rappel sequence.

Before each rappel, confirm out loud:

• Is the self-belay on?
• Are the rope ends tied off?
• Is the backup set?
• Is the belay device set correctly?
• Is the carabiner gate closed?

TOM

Self-belay, check! Ends tied, check! Rope down!

Backup, check! Device, check! Gate, check! Going down!

Saying it out loud forces you to observe your own actions objectively — and it lets your partner check you too.

Part 3: Comparing Devices — Choosing for the Situation

ATC-Style Devices

The ATC (Air Traffic Controller) style device is the most common rappelling device.

Advantages

• Light and compact
• Simple to operate
• Works with two ropes
• Doubles as a belay device

Disadvantages

• Lower braking friction (can slip with thin or wet rope)
• Prone to twisting the rope

Best suited for

• Short rappels (1-2 pitches)
• Dry rock
• Rope in good condition

Guide ATCs and the GriGri

Guide-mode ATCs (such as the Mega Jul or Reverso) and the GriGri are devices with an auto-locking function.

That said, for rappelling they’re normally used in standard mode, clipped to the harness belay loop. Direct belay mode (clipped straight to the anchor) isn’t generally recommended, since the device can’t be retrieved afterward.

In standard mode, the auto-lock function doesn’t engage — so a backup is just as necessary as with a plain ATC.

Advantages

• Higher braking friction
• Auto-lock available when belaying
• Some models work with two ropes

Disadvantages

• The GriGri is relatively heavy
• Requires a backup during rappelling, since it’s used in standard mode
• Takes practice to operate smoothly

Best suited for

• Longer rappels (3+ pitches)
• Wet or thick rope
• Multi-pitch climbing (using one device for both belaying and rappelling)

The Figure-8 Device (Eito-kan)

The figure-8 device is a classic rappelling tool.

Advantages

• High braking friction
• Simple and durable
• Heat-resistant

Disadvantages

• Heavy
• Twists the rope significantly
• In alpine climbing, less suited to belaying than a Guide ATC

Best suited for

• Longer rappels (5+ pitches)
• Rescue work (lowering heavy loads)
• Situations where it’s the only device on hand
• Stream climbing (sawanobori)

The Munter Hitch

The Munter hitch is a rappel method using only a carabiner. Plenty of beginners drop their device at some point — everyone should be able to rappel this way as a fallback.

Advantages

• No device required
• Useful in emergencies

Disadvantages

• Lower braking friction
• Twists the rope significantly
• Puts extra strain on the carabiner

Best suited for

• Having dropped your device
• Device malfunction
• Short rappels (1 pitch only)

My Own Selection Criteria

For multi-pitch climbing, I favor a Guide ATC — the auto-lock function adds real safety margin when belaying.

When teaching beginners, I start them on an ATC-style device with a backup. Once they understand the fundamentals, they can move on to more advanced devices.

Part 4: Anchor Building and Human Error — Judgment That Saves Lives

Choosing the Anchor

Anchor selection for rappelling matters even more than for a belay station, because during a rappel you’re away from the anchor — if it fails, the fall is immediate and fatal.

Good anchors

• Bolts (in good condition)
• Thick pitons (driven in solidly)
• Trees (trunk at least 20cm thick, alive)
• Rock horns (not sharp-edged, rounded)

Anchors to avoid

• Corroded bolts
• Loose pitons
• Shrubs (such as haimatsu, with unclear strength)
• Sharp rock edges (risk of cutting the rope)

Overestimating the Strength of Haimatsu

The 2019 rappelling accident on Mt. Maehotaka is attributed to using haimatsu (dwarf pine) as the anchor. The strength of the haimatsu was overestimated, and using it alone, the anchor broke and the climber fell to their death.

The countermeasure: as a rule, only use a living tree at least as thick as your arm, and test it before relying on it — always in combination with another anchor.

If haimatsu must be used, bundle 2-3 stems together, and combine it with a bolt or rock horn wherever possible.

Human Error in Anchor Building

The most common human error in anchor building is failing to check the anchor’s condition.

Is the bolt corroded? Is the piton loose? Is the tree alive? Skipping these checks before starting a rappel raises the risk of anchor failure significantly.

When I check an anchor, I go through the following:

• Bolt: Is it rusted? Does it spin?
• Piton: Pull on it like you’re testing with a hammer, and tap it — a high, clear ring means it’s sound, a dull thud means it’s loose.
• Tree: Shake the trunk to check the root condition.
• Rock horn: Is it sharp? Will it abrade the rope?

Give Anchor Building Time

Anchor building deserves unhurried attention. A rushed anchor carries a much higher risk of error.

Even in bad weather or with nightfall approaching, take care with the anchor above all else. Five extra minutes can save a life.

Part 5: Backup Systems — Surviving a Single Mistake

Why a Backup Matters

Letting go of the rope mid-rappel happens more often than you’d think.

• A falling rock strikes the hand gripping the rope
• Clothing or a towel gets caught in the device
• Fatigue causes a hand to slip
• Panic causes someone to let go
• The body collides with rock
• The rope is too short, or doesn’t reach the landing point

Without a backup, any of these situations means an immediate fall. With a backup, a single mistake doesn’t have to be fatal.

Backing Up With a Friction Hitch

The most common backup is a friction hitch — a Prusik, Klemheist, or Autoblock (Machard) hitch.

Use a roughly 7mm × 150cm cord, wrapped 3-4 times below the belay device. Under load, it bites into the rope and locks.

Placement: Set it below the belay device. Placed above, it can leave you unable to move once loaded.

Number of wraps: Three wraps is standard, though this varies with rope diameter and cord diameter. Always test it under tension before descending to confirm it locks reliably.

When to Release the Backup

Keep the backup active throughout the rappel. Only release it once you’ve reached the next anchor and clipped in a self-belay.

Never release the backup mid-rappel. If you need to briefly let go — to untangle a snagged rope, for instance — shift your weight onto the backup first.

Auto-Locking Devices Still Need a Backup

Even with an auto-locking device like a GriGri, a backup is essential for rappelling.

These devices auto-lock when belaying, but during a rappel they’re used in standard mode (clipped to the harness), so the auto-lock function doesn’t engage (solo-climbing systems are an exception). Direct belay mode (clipped straight to the anchor) generally isn’t used, since it can’t be retrieved.

In standard mode, braking friction is high, but letting go still means falling. Without a backup, it carries the same risk as a plain ATC.

Whatever device I use, I require a backup whenever rappelling first as the lead. Regardless of device, building a system that survives a single mistake is what matters.

Part 6: Judgment by Terrain — Rock Faces vs. Stream Gorges

Rappelling on Rock

Rappelling on a rock face is relatively straightforward. Anchors are usually fixed bolts or pitons, and retrieving the rope is easy.

Points to watch

• Condition of fixed anchors (corrosion, looseness, strength of any fixed sling/webbing)
• Rope length (does the end reach the ground?)
• Throwing the rope down (avoiding snags on rock horns)
• Rope retrieval (dealing with snags if they occur)

Rappelling in Sawanobori (Stream Climbing)

Rappelling in a stream carries its own set of challenges, distinct from rock climbing.

Uncertain anchor quality
Streams have few fixed anchors, so trees or rock horns are used more often. When using shrubs, bundle several together where possible.

Everything is wet
A wet rope reduces a device’s braking friction. ATC-style devices tend to slip, so a Guide ATC or figure-8 device is preferable.

Risk of rising water
Streams are prone to sudden weather changes and rising water levels, which demands a quick rappel.

Difficult rope retrieval
In gorge sections, the rope easily snags on rock horns or waterfalls. Throw the rope down carefully.

Anchor-Building Adjustments in Streams

When rappelling in a stream, I keep the following in mind:

Use multiple anchors wherever possible
Two or more anchor points — two trees, for instance.

Protect the rope
Check carefully that the rope won’t rub against a sharp rock edge.

Flake the rope for easy retrieval
Throw the rope down in a way that avoids the waterfall’s current.

Part 7: Ascending the Rope — Self-Rescue for the Unexpected

Why It’s Necessary

Sometimes you can’t confirm from the anchor whether the rope reaches the ground. Partway down, you may reach the rope’s end only to find it doesn’t touch the ground.

Without the ability to ascend the rope (nobori-kaeshi), you’re left hanging with no way to move. Extended suspension raises the risk of harness hang syndrome — a form of shock caused by blood pooling in the legs, which can be fatal.

The Basic Sequence

Ascending is done using a friction hitch.

1. Temporarily lock off the descender
Lock off the descender — for example, by wrapping the rope repeatedly around your leg, or using a mule hitch.

2. Attach a friction hitch above the descender
Attach a Prusik or Klemheist above the descender.

3. Transfer your weight to the friction hitch
Step down on the rope on the friction-hitch side to shift your weight onto it.

4. Slide the descender upward
Slide the descender up and transfer weight back onto it. Repeat this cycle.

Ascending Skills Are Non-Negotiable

If you’re going to rappel, you need to know how to ascend the rope. A party that can’t ascend has no business rappelling.

When I teach courses as a guide, I always cover ascending technique. Students practice it in a safe location until they’ve genuinely mastered it.

Summary: The Fight Against Human Error

Rappelling causes more climbing deaths than any other single technique, and nearly all of those deaths trace back to human error.

Poor anchor selection, unfinished knots, device setup mistakes, missing backups — these are mistakes that even experienced climbers make.

There are two ways to guard against them.

First, execute the sequence with certainty. Run through the checklist out loud. Have your partner confirm it too.

Second, build a system that survives a single mistake. Set a backup. Use multiple anchors. Give yourself time.

Rappelling is as much a test of judgment as it is a technical skill. I want to train climbers who can adapt to the situation in front of them, not just recite a memorized sequence.

As a guide, what I tell my clients is this: rappelling should scare you. That fear is what keeps you careful — and care is what keeps you alive.

◆ The Danger of Rappelling

• Roughly 25% of climbing accidents happen during rappelling
• Most accident causes trace back to human error
• Anchor failure, rope pull-through, device mistakes, missing backups

◆ The Basic Sequence

1. Self-belay
2. Thread the rope through the anchor
3. Flake the rope, tie off the ends
4. Set the backup
5. Set the belay device
6. Begin the descent
7. Self-belay at the next anchor

◆ Comparing Devices

• ATC-style: lightweight, simple, lower braking friction
• Guide ATC/GriGri: auto-lock, heavier, requires practice
• Figure-8: high friction, heavy, twists the rope
• Munter hitch: emergency use, no device required

◆ Anchor Building and Human Error

• Check anchor condition (bolts, pitons, trees, rock horns)
• Use haimatsu only as a tested, living anchor combined with others
• Give anchor building unhurried time

◆ Backup Systems

• Friction hitch below the belay device
• 7mm × 150cm cord, 3-4 wraps
• A backup is recommended even with auto-locking devices

◆ Judgment by Terrain

• Rock: check fixed anchors, throw the rope carefully
• Streams: multiple anchors, wet rope, rising-water risk, difficult retrieval

◆ Ascending the Rope

• A required skill for anyone who rappels
• Shift weight to a friction hitch, then slide the descender up
• Extended suspension carries a fatal risk (harness hang syndrome)

◆ Risk Management

• Run the checklist out loud
• Build a system that survives a single mistake
• Give yourself time
• Recognize that rappelling should feel dangerous

北村智明

登山ガイド

日本山岳ガイド協会認定登山ガイドステージ2。ガイド歴10年。東北マウンテンガイドネットワーク及び社会人山岳会に所属し、東北を拠点に全国の山域でガイド活動を展開。沢登り、アルパインクライミング、山岳スキー、アイスクライミング、フリークライミングと幅広い山行スタイルに対応。「稜線ディープダイブ」では、山行の記憶を物語として紡ぎ、技術と装備の選択を語る。