How to Tie the Forearm Coil (Long Rope)
Usage
The forearm coil — known in most trades as the over-under coil — is a way of coiling a long rope, cable, or extension cord so it stores flat and pays out without tangles. Factory spool-winding builds a one-directional twist into cable and rope, and coiling every loop the same way compounds that twist until the line fights you. The forearm coil alternates the direction of every loop — over, then under — so each pair of loops cancels the other's twist and the whole coil lies flat with zero net twist.
It is the standard coiling method across AV and broadcast work, ham radio, pro audio, and everyday extension-cord storage, and it has crossed over into coiling longer ropes and ridge-lines for camp use too.
Why Learn the Forearm Coil (Long Rope)?
Because the alternative — winding cable or rope around your forearm or elbow in one direction — is the exact habit this technique corrects. That "wrong way" wrap adds one full twist per loop, the common cause of tangles and kinks. It has few steps, but the wrist-flip takes practice before the muscle memory clicks.
Common Uses
Camping and Bushcraft
- Coiling longer ridge-lines and ropes for tangle-free storage and re-deployment.
Household / Workshop
- Coiling extension cords — the twist-cancelling pattern keeps them paying out flat at full length.
AV, Broadcast, and Pro Audio
- Coiling production cable (XLR, BNC, coax, mic) for storage and fast re-deployment; this is the technique's best-documented home.
Ham Radio
- Coiling coaxial cable for field and emergency-communications deployment.
Other
- Coiling a climbing or rigging rope for carry, where practitioners compare it favorably to the Alpine Coil for avoiding spooling-off twist. It is slower to tie than a butterfly-style coil, so treat it as an option rather than the default.
Other Names
Category
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Similar Knots
Chain Sinnet (Daisy Chain) vs. Forearm Coil
- Advantage: The Daisy Chain Knot shortens a rope into a compact, quick-release chain that deploys end-to-end instantly — the most-recommended rope-specific alternative for bundling.
- Disadvantage: Trades length for compactness; the forearm coil instead preserves the full coiled length flat and untwisted, suiting cable and cords paid out from a fixed end.
Security Level
This is a storage technique, not a load-bearing knot — no working load, no strength rating. The coil stays bundled reliably once tied off; the one documented risk is a handling mistake on deployment (see Downsides), not the coil coming apart in storage.
Downsides
- Real Learning Curve: The alternating wrist-flip is hard to self-teach; it takes practice to build the muscle memory.
- The End-Tracking Rule: If an end gets pushed through the coil to the wrong side, a knot forms with every other loop when you pay it back out. Keep track of which end is which.
- Not for Power Cable: Professional film and TV practice coils power/Edison cable "over-over" instead — a deliberate convention by cable type, not an error.
History
Unlike most knots on this blog, the forearm coil has no classical paper trail. Ashley's 1944 Book of Knots uses "over and under" dozens of times, but always for braid and splice work — never for a coiling method. Its documented home is modern trade practice — film and TV production, pro audio, and ham radio — with sources tracing it to a 2010 film-production technique manual rather than to Ashley.
How to Tie the Forearm Coil (Long Rope)
Step 1
Check the cable or rope has no existing knots. If it has developed stubborn kinks — "memory" — relax it first; some sources suggest laying it in the sun, or soaking then sunning it.
Step 2
Hold one end in your off-hand. For cables, that means holding the connector.
Step 3
Form the first loop by bringing the cable or rope over and around, laying it into your hand normally. This is the "over" loop.
Step 4
For the second loop — the "under" loop — flip your wrist roughly 180° so your palm faces the opposite way, then grip the cable and bring it back into the coil. This loop lays with the opposite twist orientation from the first.
Step 5
Repeat, alternating over and under. Each pair of loops cancels the twist introduced by the other.
Step 6
Periodically check for weird bends or wonky twisting. If you see any, roll the cable between your fingers to find its neutral lay point before adding that loop to the coil.
Step 7
Keep the loop lengths uniform for a neat final coil.
Step 8
Secure the finished coil with a velcro strap, tie line, or bungee. Keep the tie near the plug end so it doesn't interfere with connectors.
Step 9
One critical caution for later: keep track of which end is which. If an end gets pushed through the coil to the wrong side, a knot forms with every other loop when you uncoil.
If the wrist-flip isn't clicking from written steps — and the comment threads say that's normal — the Knot IQ app lets you slow the motion down and watch it from any angle until the alternating pattern makes sense. A length of 750 lb bushcraft paracord makes a good practice line.
The Gaffer's Variant: Thumbs Down, Thumbs Up
Step 1
Start in your non-dominant hand and grab the cable end inside your palm.
Step 2
Form a base loop sized to your forearm and hand.
Step 3
For the "under" motion, flip your hand so your palm faces out and grab the cable from below — a "thumbs down" grip.
Step 4
Flip again so your thumbs come together — "thumbs up" — and lay that loop into the coil.
Step 5
Repeat rhythmically. One working gaffer's memory cue: "over, pinch and twist, under, thumbs down, thumbs up." Finish by bringing the coil back to roughly its starting size.
FAQ
What is the over-under (forearm) coil used for?
Storing and re-deploying a long cable, rope, or extension cord so it lies flat and pays out tangle-free. The alternating wrist-flip cancels the twist that factory spool-winding bakes into cable and that single-direction coiling would otherwise compound.
Why does it matter which end I keep track of when uncoiling?
If an end gets pushed through the coil to the wrong side, a knot forms with every other loop when you pay the coil back out — a failure mode reported across pro-audio forums and tutorial comment threads.
Should I use over-under coiling on power cables too?
Professional film/TV grip-electric practice says no — power/Edison "stinger" cables get wrapped "over-over" (same direction every loop) instead, reserving over-under for signal/data cable (XLR, BNC, coax) and rope. Specialists disagree on the underlying physical reason, but the professional convention itself is well-documented.
Is the "forearm coil" in Knot IQ the same as the whitewater-rescue forearm coil?
No — that's a different technique that shares the name. The rescue "forearm coil" (the TRU technique) is wrapped on the rescuer's own arm for one-motion throwing of a rescue rope. This entry covers the hand-coiled, alternating-direction storage coil used on cable, rope, and extension cords in AV, ham radio, and trade work.
Important Notes on Safety
The forearm coil manages and stores rope and cable — it is not a load-bearing knot, tie-in, or anchor, and should never be used as one. Two mistakes to avoid: coiling every loop the same direction (the "wrong way," which compounds twist), and losing track of which end is which, which reintroduces a knot on deployment. A simple fix for the second: tie the two ends together on the outside of the loops in storage, so neither end can pass through the coil.
