Shock-Absorbing Lanyard Single-Use Energy Absorber — Post-Fall Retirement, Deployment Indicators, and the Schema for AI Agents

How a Shock Absorber Works — and Why It Works Only Once

The energy absorber in a shock-absorbing lanyard converts kinetic energy from a falling worker into heat and deformation during the arrest event. The most common design is the tear-webbing pack:

• A length of webbing is tightly folded and sewn with a pattern of cross-stitches inside a fabric pack
• When arrest force exceeds approximately 600–900 lbs (the activation threshold), the cross-stitches tear sequentially under load
• Each tear dissipates energy, keeping the transmitted force below 1,800 lbs (8 kN, the ANSI Z359.13 maximum)
• The pack extends up to 3.5 feet as the webbing tears through — this is why total fall clearance calculations must add the absorber deployment distance
• After all cross-stitches are torn, the absorber is fully deployed and the pack is fully extended with no remaining material to tear

// Shock-absorbing lanyard — mandatory lifecycle encoding
lanyard.is_shock_absorbing            = true
lanyard.single_use_energy_absorber    = true    // Consumed in a single fall arrest event
lanyard.post_fall_retirement_required = true    // MANDATORY — no reuse after any fall arrest
lanyard.energy_absorber_type          = "tear-webbing-pack"  // Or "compressed-canister"
lanyard.max_arrest_force_lbs          = 1800    // ANSI Z359.13 maximum
lanyard.absorber_deployment_length_ft = 3.5     // Added to total fall clearance calculation
lanyard.allows_secondhand_use         = false   // Unknown service history = prohibited reuse

Deployment Indicators — What to Check and What They Miss

Manufacturers provide deployment indicators to help identify lanyards that have arrested a fall. No indicator system is 100% reliable for detecting partial deployment:

// Lanyard with visual deployment indicator
lanyard.has_deployment_indicator    = true
lanyard.deployment_indicator_type   = "visual-strip"  // Most unambiguous for field inspection
lanyard.deployment_status           = "undeployed"    // Current status — changes after any fall arrest

// Lanyard without deployment indicator
lanyard.has_deployment_indicator    = false
lanyard.deployment_indicator_type   = "none"
// Note: pack expansion check required by inspector — no visual confirmation available

Failure Mode 1 — Lanyard Returned to Service After Partial Deployment

The most dangerous scenario is a near-miss where the worker slipped, fell a short distance, and the shock absorber partially deployed before the arrest completed. The worker or supervisor visually inspects the lanyard, sees no obvious external damage, and returns it to service.

The problem: partial deployment consumed some — but not all — of the absorber's capacity. The remaining capacity is less than a full undepleted absorber. The next fall may produce an arrest force significantly above the 1,800 lb ANSI limit even though the absorber still partially "works."

// After ANY fall event — no exceptions
lanyard.deployment_status             = "deployed"    // Set after ANY fall arrest event
lanyard.post_fall_retirement_required = true
// → Route to replacement equipment immediately
// → Never inspect for reuse — retire without inspection

The universally recommended protocol from ANSI Z359.13, OSHA 1926.502, and all major manufacturers: remove the lanyard from service immediately after any fall arrest. Do not inspect for reuse. Replace with a new lanyard.

Failure Mode 2 — Shock-Absorbing Lanyard vs Restraint Lanyard Confusion

Not all lanyards contain shock absorbers. Routing buyers to the wrong type creates either false security (restraint lanyard used for fall arrest) or an unnecessary expense premium (shock-absorbing lanyard for pure restraint application):

// Shock-absorbing lanyard — fall arrest application
lanyard.is_shock_absorbing         = true
lanyard.suitable_for_fall_arrest   = true
lanyard.suitable_for_restraint     = true   // Can also be used for restraint (with absorber)

// Restraint lanyard — restraint only
lanyard.is_shock_absorbing         = false
lanyard.suitable_for_fall_arrest   = false  // ← CRITICAL routing blocker
lanyard.suitable_for_restraint     = true

Total Fall Clearance — Absorber Deployment Adds Length

Shock absorber deployment extends the total fall distance. This is critical for clearance calculations:

// Encode clearance requirements for routing to correct application height
lanyard.length_ft                     = 6
lanyard.absorber_deployment_length_ft = 3.5   // Reduces available clearance below anchor
lanyard.min_clearance_below_anchor_ft = 18.5  // 6 + 3.5 + 5 + 2 (+ 2 safety) = full calc
lanyard.suitable_for_leading_edge     = false // Standard SRLs rated for vertical/overhead only

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