How to Pass a Knot on Lower Through the CLUTCH Using an AZTEK // CMC Pro Tip


This Pro-Tip video demonstrates a knot pass on a lower through a CLUTCH using an AZTEK.

The AZTEK is an extremely versatile tool to complete a knot pass through a system. The AZTEK can be used for a knot pass on a raise or lower and can be used on a Twin Tension Rope System (TTRS) or a Dedicated Main/Dedicated Belay (DMDB). In this video we demonstrate how to perform a knot pass using an AZTEK on a TTRS lowering system with dual CLUTCHes.

The AZTEK is what is referred to as a piggyback haul system. A piggyback haul system or “pig rig” is an independent rope system that attaches to the main line. While this video demonstrates using an AZTEK for the knot pass, a built on-site or other pre-rigged mechanical advantage system can be used if there is a progress capture on the piggyback system that is used. A 3:1 with a progress capture built with a separate rope or a CSR2 Pulley System would be examples of this. It is important that the AZTEK or any other piggyback haul system be attached to 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.

This video is 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 CLUTCH on the knotted rope.

3. Extend the AZTEK approximately 12 inches or 1/3 meter.

4. Tie a separate prusik hitch in front of the CLUTCH and attach the AZTEK.

5. Attach the other end of the AZTEK to the anchor.

6. Check the system.

7. Continue lowering with the CLUTCH on the knotted rope until the AZTEK has taken the load.

8. Unlock the CLUTCH, remove the knotted rope and rig the rope so the knot is in past the CLUTCH.

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

10. Lock the CLUTCH.

11. Lower with the AZTEK and second rope until the CLUTCH on the knotted rope is loaded.

12. Disconnect the AZTEK and additional prusik from the system, unlock the CLUTCH.

13. Continue the lower with both ropes.