Minimum Clearance Distance in Fall Arrest Systems with Energy Absorber Lanyards.

Area of Science:

• Occupational Safety and Health
• Materials Science
• Mechanical Engineering

Background:

• Falls from height are a leading cause of workplace fatalities.
• Fall arrest systems (FAS) are crucial for preventing severe injuries by safely arresting falls.
• Energy Absorber Lanyards (EALs) are key components of FAS, but their performance and required safety clearances are not well-documented.

Purpose of the Study:

• To determine the minimum clearance distance (MCD) required below an anchorage point for safe fall arrest using EALs.
• To investigate the real-world deformation and elongation of EALs during fall arrest.
• To assess the reliability of manufacturer-provided MCD data and compliance with safety standards.

Main Methods:

• Dynamic behavior tests were conducted on ten EAL models from six international manufacturers.
• Image processing techniques were employed to measure the total elongation (elastic and plastic) of the EALs.
• Comparison of experimental results with the elongation predictions from EN 355:2002 standard.

Main Results:

• Maximum plastic elongation of EALs could be reduced by up to 29%.
• The EN 355:2002 standard underestimates EAL elongation by as much as 70% for certain products.
• 20% of tested EALs exceeded the maximum allowable arrest force (Fm) specified in EN 355.
• Manufacturer-provided MCD data was found to be unreliable and incomplete.

Conclusions:

• Current manufacturer data for MCD is insufficient and unreliable for ensuring fall arrest safety.
• There is a critical need to strengthen quality control for EALs to ensure compliance with EN 355 standards.
• It is recommended to increase the MCD beyond calculations based on EN 355, suggesting a minimum of 1 meter clearance.