Instructor Tutorial: How to Tie a Flat Overhand for Joining Rappel Ropes
In this tutorial, Corey, an ACMG Apprentice Alpine Guide with Mountain Skills Academy and Adventures, demonstrates how to tie, dress and tighten a flat overhand for joining rappel ropes.
A flat overhand is a joining knot formed by tying two rope ends together in a single overhand knot. Corey’s demonstration focuses on leaving adequate tails, tightening each strand separately and checking that the finished knot is compact and firm. Suitability for rappelling depends on the specific ropes, manufacturer instructions and complete rappel system.
Step 1: Prepare the Rope Ends
Corey begins with two ropes and feeds a rope through the anchor before bringing the ends together.
Leave enough spare rope to finish with at least 30 cm of tail on each rope after tightening, as demonstrated in the video. Follow any longer tail requirement specified for your equipment.
Step 2: Tie the Flat Overhand
Hold the two rope ends together and tie a single overhand knot using both strands, following Corey’s demonstration.
Keep track of both tails as you form the knot so that neither becomes too short during tightening.
Step 3: Dress the Knot
Arrange the strands neatly and remove slack from within the knot.
Dressing means organizing the rope into the intended knot shape before tightening it fully. Check that the strands sit neatly together and that the knot matches the demonstration.
Step 4: Tighten All Four Strands Individually
Corey demonstrates four separate tugs. Tighten each of the four strands individually: the two standing strands and the two tails.
Follow this with the two pushes shown in the video, working the knot together from both directions. The finished knot should feel compact and firm.
Step 5: Recheck Both Tails
Once the knot is fully dressed and tightened, check the remaining tail on each rope.
Confirm that both tails still meet the demonstrated minimum of 30 cm, or any longer requirement specified by the manufacturer. If either tail is too short, retie the knot with more rope available.
Final Check
Before using the knot, confirm that:
- The knot is correctly formed and matches the demonstration.
- The strands are neatly dressed, with no loose sections.
- All four strands have been tightened individually.
- Both tails meet the required length after tightening.
- The rope combination, joining method and complete rappel setup are suitable for the intended use.
A firm knot is one part of this check; it does not establish that the entire rappel system is suitable.
Safety Note: Rope Compatibility and Qualified Instruction
Corey mentions joining a 9 mm rope to a 6 mm rope in this video. Diameter alone does not establish whether that combination is suitable for rappelling. Petzl’s guidance advises against using a single flat overhand to join ropes of different diameters.
Confirm the requirements for the exact rope materials, rope models, joining method and rappel system with a qualified climbing professional. Do not assume that any 6 mm cord can serve as a rappel rope.
This tutorial is a companion to practical instruction. Practise under the supervision of a qualified climbing professional and follow the manufacturer’s instructions for all equipment in the system.