Types of Anchors in Rigging and Rescue

1. Single-Point Anchors: Utilize a solitary, robust anchor point, such as a sturdy tree or a securely installed bolt. These are straightforward but depend entirely on the strength and stability of one point.
2. Multi-Point Anchors: Combine multiple anchor points to distribute the load, enhancing stability and redundancy. Common configurations include:
   • Load Sharing Anchors: Distribute the load among multiple points, though not always equally.
   • Load Distributing Anchors: Adjust to share the load equally among anchor points, even if the direction of the load changes.
3. Natural Anchors: Incorporate existing environmental features like boulders or rock formations. While convenient, their reliability must be thoroughly assessed.
4. Artificial Anchors: Involve man-made devices such as bolts, pitons, or anchor plates. These are often used when natural anchors are unavailable or unsuitable.

Anchors Overview

Anchors are the foundation on which we build our rescue systems. Rescuers must quickly decide on an appropriate anchor system for a given rescue situation. Usually, anchors need to be in place before other aspects of the rescue can proceed. Determining where anchors should be built and beginning their construction early are critical steps in timely rescue operations. Here’s a quick review of anchors and related keywords we’ll cover throughout this course:

Anchor
An Anchor is a general term for the combination of everything combined. Single connection point (e.g. tree, boulder, camming device, etc.).

Anchor Point
An Anchor Point is a single object or component used either alone or in combination with others to create an anchor system capable of withstanding a significant force.

Anchor System
An Anchor System is one or more anchor points connected in order to provide a secure connection. Multiple anchor points rigged together creating a redundant system.

Deviation
Redirects the natural fall line of the rope on the rock face. A deviation point may or may not to be subjected to the same force as the primary rig point.

Directional
Rigging technique to change the natural line of a rope with a carabiner or pulley attached to an alternative anchor.

Focal Point
A location, floating or fixed, where all rigging is directed for anchor points. This concept disciplines rescuers to construct rigging which joins together at an efficient point, rather than unwittingly resorting to wherever the knot that joins all anchor points ends up due to the length of material used; the latter can result in an awkward spot to manage rope handling tasks.

We will always try to engineer our anchor systems with housekeeping in mind. Though a single “bombproof” anchor may be strong enough to support an entire rescue system, including multiple load bearing lines, we may still build a second anchor for convenience and cleanliness and to allow more workspace for rescuers. Rescue systems are often more efficient and easier to operate with redundant load bearing lines rigged on separate anchors.

E – Equalized
In a system with multiple anchor points or multiple strands of anchor material, the various components of the anchor system should bear roughly equal parts of the load. Self-equalization is not required. Pre-equalize the anchor for the anticipated direction of pull.

R – Redundant
Failure of any one component of an anchor system should not lead to complete anchor failure. For example, construct the anchor system so that if one strand of software is severed, at least one additional strand capable of supporting the load will remain intact.

N – Non–Extending
Failure or shifting of one element in the anchor system should not cause significant movement of the load. This is why we fix and focus our multi-point anchor systems and why we generally avoid self-equalizing anchors. The location of anchor points relative to one another is also a factor in this stage of anchor system analysis. Failure of one anchor point should not result in excessive swinging of the load toward the remaining anchor point or points.

S – Solid
Choose the strongest available anchor point. If no single anchor point seems strong enough then combine multiple anchor points until you are confident your anchor system is strong enough. Build your anchor with materials at least as strong as the weakest point in your system.

T – Timely
Balance the need for strong anchors with the need to reach your patient as quickly as possible. Simpler is usually better.

Single Point Anchors

Within a Single Point Anchor, there are two types of connections:

1. Indirect for webbing, cord, and other such material.

2. Direct which uses the actual working or belay lines themselves.

Multipoint Anchors

Often, single point anchors are either non-existent or marginal, thus necessitating the need for multipoint anchor systems.

• Rigging a backup or secondary connection to a separate anchor.

• Available anchor points are not exactly where they need to be.

• A directional shift is possible during the evolution

Four Types of Multipoint Anchor Systems:

1. Slack Anchors Systems: These are non-tensioned systems are more for backups.

2. Tensioned Anchor Systems: These utilize some form of tensioned mechanical advantage rope system between anchor points. PreTensioned back-ties, non-working 3:1 MAs, AZTEKS, Munter Mule are examples.

3. Load Sharing Anchor Systems.

4. Load Distributing Systems.

Theory of Anchors

Anchors are the most critical component of any rope rescue system. The entire rescue is in jeopardy if the anchors are not reliable. Anchor systems are made up of two major elements:

1. Choosing the best anchor (i.e. boulders, vehicles, trees, and bolts), and

2. Rigging the anchor

Key Considerations for Anchor Selection

• Strength and Stability: Ensure each anchor point can withstand anticipated loads with an appropriate safety margin.
• Redundancy: Incorporate multiple anchor points to prevent system failure if one point fails.
• Load Distribution: Aim for equal load sharing among anchor points to maintain balance and reduce strain on individual anchors.
• Angle Management: Keep angles between anchor legs as small as practical to minimize additional forces on the anchors.
• Environmental Impact: Choose anchor points and methods that minimize damage to the surrounding environment.

For a comprehensive guide on rescue and rigging anchor systems, refer to the RLA – The Foundations of Rescue and Rigging Anchors Systems – eBook.

By meticulously selecting and constructing anchors, professionals can ensure the integrity and safety of their rigging systems, thereby safeguarding both personnel and equipment.

Peace on your days…

Lance