Mechanical Advantage Piggyback Knot Passing

Written By: Lance Piatt

mechanical advantage system - piggy back knot passing

The Mechanical Advantage Piggyback Method is an advanced rigging technique used in rope rescue operations to manage and pass knots effectively, especially in scenarios involving mechanical devices like the Clutch or MPD. This method utilizes an additional mechanical advantage system, such as an AZTEK, to facilitate the maneuvering of knots past critical points in the rope system. Here’s a detailed breakdown of how to execute this method step-by-step:

Step 1: Initial Setup and Positioning

  • Begin by raising the load until the knot is positioned just below the Clutch. At this point, rotate the Clutch handle to ‘Stop’ to secure the rope temporarily.
  • Connect the piggyback system to a solid anchor point. Using a Prusik hitch, attach this secondary system directly to the rope. This setup is crucial as it prepares the secondary system to take over the load momentarily.

Step 2: Manipulate the Knot

  • Continue to raise the load using the piggyback system until there is enough space to maneuver the knot to the other side of the Clutch. Ensure there is sufficient space between the piggyback system and the knot to safely install and operate the Clutch.
  • Carefully remove the rope from the Clutch and re-rig it so that the knot is positioned past the Clutch. After repositioning the knot, remove any slack from the system and rotate the Clutch handle back to ‘Stop’.

Step 3: Transfer Load and Continue Operation

  • Utilize the piggyback system to gently lower the load until the tension is transferred back onto the Clutch. This step is critical as it ensures the primary system is correctly loaded and ready to continue the operation.
  • Once the load is securely on the Clutch and the system is stable, remove the piggyback system entirely from the rope.
  • Continue to raise the load using the Clutch, now that the rope system is free of knots and correctly configured.

Advantages of the Mechanical Advantage Piggyback Method

  • Efficiency in Knot Handling: This method provides a seamless and safe way to handle knots during rope rescue operations, ensuring that they do not interfere with the functionality of the Clutch or other descent control devices.
  • Enhanced Safety: By employing a secondary system, this method allows for greater control over the load, especially in critical phases of knot transfer.
  • Flexibility: Suitable for various types of mechanical advantage devices, the Mechanical Advantage Piggyback Method adds a layer of flexibility to rescue operations, adapting to different types of equipment and scenarios.

This technique ensures that rope rescues are conducted with a high level of safety and efficiency, enhancing the overall effectiveness of the operation. By mastering this method, rescue teams can improve their operational capabilities and ensure a smoother execution of rescue missions involving complex rope systems.

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