PAS vs Daisy Chain: The Definitive Anchor Safety Guide

You reach the chains, your breath ragged, and clip in. The metallic click of the gate closing signals a transition from movement to stillness. In this moment, you trust your life to a single tether.

For decades, climbers have misused aid-climbing tools for this critical connection, largely unaware that a two-foot slip on static material can generate forces capable of snapping bone or gear.

I have spent years teaching anchor transitions, and I still see climbers relying on equipment designed for static body weight rather than fall arrest. The era of the traditional daisy chain as a personal safety tether for free climbing is over. Understanding why—and adopting the modern safety hierarchy of rock climbing anchoring—is the only way to ensure the mountains don’t penalize a momentary lapse in judgment.

This guide dissects the material physics of the “static trap,” exposes the structural flaws of the daisy chain, and explains why the dynamic lanyard is the only system that actively engineers human error out of the equation.

The Core Conflict: Why is “Strong” Not Always “Safe” in Climbing Anchors?

A dangerous misunderstanding exists in the sport climbing and alpinism communities: that “high breaking strength” is synonymous with safety. This fallacy is known as the “Static Trap.” It assumes that because a sling or runner is rated to 22kN rating (enough to lift a truck), it is safe to use as a personal tether.

What is the “Static Trap” and how does it endanger climbers?

Safety in a fall scenario is not defined by how much weight a material can hold statically; it is defined by the material’s ability to absorb energy. Materials like Dyneema, Spectra, and even tight-weave Nylon (Polyamide) behave much like steel cables. They are incredibly strong, but they stretch less than 3-5% before failure.

When you fall on a dynamic lead rope, the rope elongates, softening the catch. When you slip onto a static tether, there is almost no elongation. The kinetic energy cannot dissipate through the material, so it transfers directly to the climber’s internal organs and the anchor bolts.

This danger is amplified by the geometry of the anchor. Because the tether is short, a slip of just two feet creates a high fall factor (often Factor 1 or 2).

Drop testing from facilities like the Black Diamond QC Lab reveals that a 60cm Factor 1 fall on a static Dyneema sling can generate approximately 16.7kN of force. This far exceeds the 10kN threshold where severe bodily trauma occurs. You might verify the strength of your gear by reading a detailed analysis of anchor chain materials, but you must remember that the 22kN rating creates a false sense of security. It tells you the gear won’t break, but it doesn’t tell you that your pelvis might suffer internal organ damage.

For the regulatory framework and testing data that distinguishes static slings from dynamic safety devices, refer to the UIAA Safety Standards for Belay Lanyards.

The Anatomy of Danger: Why Should the Daisy Chain Be Retired from Free Climbing?

Once you understand the physics of shock loading, the specific structural flaws of the most misused static tool—the daisy chain—become glaringly obvious.

How does the “Magic Trick” mis-clip scenario lead to catastrophic failure?

Daisy chains were born in the world of aid climbing. They were designed for body weight positioning while a climber stood in aiders to place the next piece of gear. They were never intended to arrest a fall or serve as a primary belay lanyard.

The pockets of a daisy chain are formed by bar-tack stitching. While the main runner is strong, this individual pocket strength is typically rated for only 2-5kN rating—barely more than body weight.

The catastrophic failure mode occurs during the “Magic Trick” mis-clip scenario. This happens when a climber clips a carabiner across the stitching between two pockets rather than through the loop itself.

If you load the system in this configuration, the weak bar-tacks rip. Because the carabiner is not actually inside a closed loop, the ripping action causes the carabiner to detach completely from the system. You are no longer attached to the wall. This is often referred to as a mis-clip catastrophe.

This error is terrifyingly easy to make and difficult to spot, especially when the system is unweighted or clustered at a busy belay stance. Manufacturers like Black Diamond have issued explicit warnings prohibiting daisy chain use for personal anchoring, yet the practice persists due to naming confusion.

For a forensic account of a real-world accident caused by mis-clip catastrophe, read the American Alpine Club Accident Reports: Improperly Clipped Tether. Recognizing this specific failure mode analysis is a key step in preventing common climbing dangers that occur during transitions.

Pro-Tip: If you absolutely must use a daisy chain (perhaps in an emergency), strictly clip only the end loop and one other pocket. Never shorten it by clipping two adjacent pockets with a single carabiner.

The Evolutionary Leap: How Does the Modern PAS Improve Upon the Daisy Chain?

The industry recognized the inherent danger of the daisy chain and responded with the Personal Anchor System (PAS), typified by the chain-link style design.

What distinguishes the “Chain Link” construction from the traditional daisy chain?

Modern PAS devices, such as the Metolius PAS 22, Sterling Chain Reactor, or the Black Diamond Link Personal Anchor, utilize a series of separate, interlinked rings of webbing. This design change is significant because it introduces full loop strength redundancy.

Every single loop in a chain-link PAS is rated to 22kN. This eliminates the “weak pocket” hazard found in daisies. More importantly, the interlocking sewn loops construction makes the “Magic Trick” physically impossible. Even if you clip across the bar-tack or a link, the structure prevents the carabiner from detaching.

However, we must return to physics. While the PAS solves the structural failure issue, most are still made of static nylon or Dyneema blends (like Monster Webbing). They are certified under UIAA 104 (Slings) or EN 566, not as energy-absorbing lanyards.

A fall on a static PAS or static chain will still generate massive impact forces. It solves the issue of the tether breaking, but it does not solve the issue of the shock load injuring the climber.

The academic testing protocols for these strength ratings can be found in the Chichester University Research on Climbing Equipment Standards. While these devices are popular for tasks like cleaning a sport anchor, climbers must remain vigilant about keeping the tether taut.

The Dynamic Revolution: Why Are Rope Lanyards the New Gold Standard?

Solving the strength issue was only half the battle. The final evolution in safety required addressing the physics of the fall itself through dynamic evolution in materials.

How does UIAA 109 certification change the safety calculus for personal tethers?

The introduction of UIAA 109 certification (and the European CEN 17520) marked a divergence between static slings and true Belay Lanyards.

Devices like the Petzl Connect Adjust, Beal Dynaconnexion, or the Camp Swing use actual dynamic climbing rope (Nylon 6,6). This construction provides inherent stretch and energy absorption, similar to your lead line.

Furthermore, the dynamic adjuster mechanisms on these lanyards are designed to slip slightly under high loads. This slippage converts kinetic energy into heat, further aiding in impact force reduction.

UIAA 109 devices are required to cap impact forces below 10kN, even in severe fall scenarios (Fall Factor 2). This protects both the climber and the anchor points.

Beyond physics, these systems offer ergonomic advantages. The ability to use an adjustable rope position with one hand allows for precise positioning at the belay, reducing the likelihood of slack in the system. The dynamic nature of the lanyard acts as a buffer for the “Human Factor,” forgiving small errors like climbing above the anchor.

Broad safety guidelines from the National Park Service Climbing Safety Guidelines increasingly recommend dynamic systems. These lanyards also integrate seamlessly with essential self-rescue skills, serving as adjustable tethers during rappels or escapes.

Operational Best Practices: How Do You Stay Safe Regardless of Your Tether Choice?

Regardless of whether you use a static chain or a dynamic lanyard, your safety ultimately depends on the operational discipline and anchor management you maintain at the belay.

Why is the “No Slack” rule the single most critical habit for anchor safety?

Slack is the enemy. In an anchor system, slack is the precursor to a shock load. The “No Slack” rule dictates that you must maintain tension on your tether at all times.

If there is zero slack, the fall distance is zero (Fall Factor 0). The moment you clip the anchor, adjust your positioning or your tether length until it is taut.

Before you untie from the rope or begin cleaning anchors, you must physically weight the system. Sit back in your harness. Verify that the tether is holding and that the carabiner is locked.

Pro-Tip: Always inspect the girth hitch at your harness tie-in points. It should be snug and dressed cleanly around the soft points (swami belt and leg loop cross-piece), not the belay loop, to prevent metal-on-fabric abrasion and keep your belay loop free for rappelling.

Redundancy is your backup. When transitioning, keep a quickdraw clipped to a bolt or leave the rope clipped until the very last moment. If you don’t have a dedicated tether, a clove hitch with the climbing rope is often the safest and most adjustable option.

Educational resources from the American Alpine Club Education Center reinforce these protocols. You can view the “No Slack” rule as a critical layer of defense within the Swiss Cheese Model of accident causation, blocking the alignment of errors that leads to an accident.

Conclusion

The evolution of anchor safety is clear. The daisy chain, with its risk of mis-clipping and weak pockets, is unacceptable for personal anchoring in free climbing.

While static PAS chains provide structural strength (22kN), they do not protect you from the physics of a shock load. The modern standard has shifted to UIAA 109 certified dynamic lanyards, which offer superior energy absorption and adjustability.

However, the golden rule remains: regardless of your system, maintain “No Slack.”

Evaluate your rack today. If you are still using a daisy chain for anchoring, retire it to your aid gear pile. Upgrade to a system engineered for your safety, designed to handle the probability of failure, not just your weight.

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