Understanding Resultants in Artificial High Directionals

In the world of technical rope systems, understanding and controlling resultants is critical for ensuring the stability of artificial high directionals (AHDs). At its core, a resultant is a vector—a measure of force and direction. When applied to rigging, resultants determine whether a high directional system remains stable under load.

The Role of Resultants in Stability

Resultants are formed by the forces acting through the head pulleys of an AHD, such as a tripod or multipod. These forces exert compression, which stabilizes the frame. For the system to remain secure, the resultant vector—the combined directional force of these individual components—must fall within the footprint of the AHD’s base.

In systems with a single pulley at the head, the resultant aligns with the centerline of the pulley. For example, with a properly set up tripod, the resultants from multiple pulleys should converge and land directly in the center of the footprint, providing maximum stability.

Managing Movement and Adjusting Guying Systems

While the goal is to keep resultants within the footprint, real-world conditions can shift these forces. For instance, when performing edge transitions, an attendant moving forward can pull the lines and cause the resultant to swing towards the front. This shift necessitates careful management to maintain system integrity.

A properly tensioned guying system counteracts these movements and keeps the structure stable. In the setup described, three guying points are spaced 120 degrees apart around the frame, creating a balanced and secure structure. Various systems can be employed, including:

• Petzl Jag System: A simple set of 4s, ideal for creating tension quickly and effectively.
• Transport Hitch (Voodoo Hitch): A self-adjusting system offering easy tension management.
• Non-Working 3:1 System: Provides friction for stability but requires manual adjustment for re-tensioning.

Adapting to Different Configurations

The principles of resultants apply across different AHD configurations:

• Tripods: Offer a large footprint for resultants to land within, ensuring excellent stability.
• Monopods/Gin Poles: Require resultants to fall closer to the single pole, necessitating precise tensioning and alignment.
• Directional Frames: May involve leaning frames or gantry poles where resultants extend outside the footprint, requiring strong oppositional forces or compression legs for counteraction.

Key Takeaways

For any AHD setup, the stability of the system hinges on ensuring the resultant remains within the footprint of the frame. This involves not only proper setup and tensioning but also the ability to adapt to changes in load or movement. By understanding these principles and applying effective guying techniques, teams can ensure safety and reliability in any rigging scenario.

Gear & Equipment Used in This Setup:

• CMC Arizona Vortex 2 Multipod
• Rock Exotica Omni-Block 1.1″ Single
• Petzl Rollclip
• Petzl Tibloc Ascender
• Petzl Jag System
• Petzl Axis 11mm Rope
• Petzl Sm’D Carabiner

Explore these tools and techniques further through Rigging Lab Academy’s comprehensive training courses and resources.

Peace on your Days

Lance