Pre-Plan the Working Line for Efficient Haul Systems

All too often, teams rig their haul systems without pre-planning the layout of the working or haul line. A common scenario involves placing the progress capture device (ratchet) at a forward directional anchor located right in front of the mechanical advantage (MA) system.

While this might seem practical in the moment, this position typically results from a lack of planning and can lead to significant inefficiencies, risks, and anchor stresses during the operation.

The Root of the Problem

When teams begin rigging for a lowering system, they often position the braking system at the anchor most aligned with the fall line. This anchor, however, is often too close to the edge, offering minimal throw for the eventual haul system.

To compensate, the team must look for another anchor that provides a longer throw or better hauling field, typically further back or to the side.

This creates a cascading problem:

1. Hot Change-Over: Transitioning from lowering to raising under tension leaves only one viable location for the ratchet—at the original anchor near the edge.
2. Forward Position Ratchet: When the ratchet is placed forward of the MA system, several issues arise:
   • Slack rope during re-sets, leading to inefficient hauling.
   • The ebb and flow of tension at the directional anchor causes back-and-forth movement.
   • This dynamic tensioning risks overloading the directional anchor.

Why Is This Problematic?

The placement of the ratchet at a forward directional anchor introduces significant risks:

1. Anchor Integrity: During a raise, forces at the directional anchor increase dramatically.
   • The static weight of the load during the haul can be 141% greater than during the lowering phase.
   • A poorly planned directional anchor may not withstand this stress, especially with constant tension changes.
2. Force Multiplication at the Edge:
   • If the rope makes a 90-degree turn over a rough edge (like sandstone or granite), friction can triple the weight of the load at the edge.
   • Using a high directional mitigates this, but pre-planning the working line is still essential.
3. Dynamic Forces: The back-and-forth motion of the directional anchor caused by tension fluctuations further weakens anchor integrity. The continual shifts in force vectors magnify the potential for failure.

The Simple Solution: Pre-Plan Your Haul System

To eliminate these risks, pre-planning your working line and haul system is essential. Here’s how:

1. Strategic Braking Device Placement
   • From the outset, position the braking device for lowering at the location where the ratchet will eventually reside.
   • This anchor must allow for an efficient throw and proper alignment for the future haul system.
2. Anchor Selection
   • Choose a directional anchor strong enough to withstand the forces generated during the raising phase—not just the lowering phase.
   • Factor in edge friction and consider using a high directional to minimize additional force at the anchor.
3. Plan for the Transition
   • Anticipate the change-over from lowering to raising and design the system accordingly.
   • Avoid building systems that require re-rigging under tension.

Why Pre-Planning Matters

Pre-planning the working line layout offers several key benefits:

• Efficiency: Eliminates re-rigging and reduces slack during resets.
• Safety: Ensures the directional anchor can handle the full forces of a raising system.
• Stability: Prevents dynamic tensioning that compromises anchor integrity.

Edge Friction: A Critical Factor

Always consider the friction profile of your edge:

• 90-degree turns over rough rock surfaces (e.g., sandstone or granite) add massive loads to the system—sometimes 3x the static load.
• Using a high directional dramatically reduces edge friction and ensures better load management.

Final Thoughts

The key to a safe and efficient haul system lies in pre-planning the working line. By positioning the braking device and ratchet at the optimal location from the beginning, teams can eliminate the risks associated with forward directional anchors, dynamic tensioning, and poorly designed transitions.

Take the time to pre-plan—your anchors, your team, and your system depend on it.

Peace on your days,
Lance

Explore More at Rigging Lab Academy:

• In-Depth Review of Mainline Systems
• Hauling Systems and Force Vector Management
• High Directional Advantages in Technical Rescue

Peace on your Days

Lance