How to Pass a Knot on a Lower Through the CLUTCH Using the Tie-Off Method // CMC Pro Tip


This Pro-Tip video demonstrates a knot pass on a lower thru a CLUTCH using the tie off method.


Passing a knot through a system is an important skill for a Rope Rescue Technician. In addition to extending the rope’s length by tying two or more ropes together, a knot can be used to isolate a short section of rope that is damaged by an edge, etc. in order to complete a rescue without having to stop and swap out the lifeline in the midst of the operation. The Alpine Butterfly is a great knot to use to isolate a damaged section of rope by ensuring the damaged section is in the unloaded loop created by the knot. Once a knot is in the system, a Rope Rescue Technician must be prepared to deal with it.


In this series we will demonstrate multiple methods to pass a knot through raising and lowering systems. The Tie-Off method should only be used in a Dual Capable Twin Tension Rope System (DCTTRS). The Tie-Off method shown in this video is the fastest and most efficient way to pass a knot that we teach in CMC School courses. It can be used when you are using dual CLUTCHes, MPDs, I’Ds, etc. It is critical that the knot being used as the tie-off, either Figure-8 on a Bight or an Alpine Butterfly, be attached to a separate carabiner on the anchor so that the potentially load-bearing carabiner attached to the CLUTCH, MPD, I’D etc is never opened (if required) until properly backed up. Stay tuned for more upcoming knot pass videos.


These videos are intended to be an adjunct to competent hands-on instruction. For more information about open enrollment or customized contract Rope Rescue and Confined Space Rescue classes please visit the CMC School Website at:


Step by Step:

1. Stop lowering when the knot is 18 inches or 1/2 a meter from the CLUTCH.

2. Lock off both CLUTCHes.

3. Tie a Figure 8 on a Bight or an Alpine Butterfly about 3 feet or 1 meter behind the knot.

4. Attach that knot to a separate carabiner on the anchor.

5. Check the system.

6. Lower the knotted rope until all of the load is on the second rope.

7. Remove the knotted rope and rig the rope so the knot is in front of the CLUTCH.

8. Make sure the CLUTCH side plate is fully closed.

9. Lock off the CLUTCH

10. Disconnect the knot from the anchor and untie it.

11. Unlock the second CLUTCH and lower until the load is equalized on both lines.

12. Unlock the CLUTCH with the knot in the rope and continue lowering.