조원제  장성은  김화일

Vol. 40,  No. 2, pp. 19-25, Apr.  2025
10.14341/JKOSOS.2025.40.2.19

safety belt anchor point lanyard type shock absorber

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This study measured the deceleration distance of the shock-absorbing device in safety harness lanyards through real-world fall experiments to verify whether the theoretical calculation method for the lowest point of the safety harness, as proposed in previous studies, is appropriate. Falls account for about 40% of workplace fatalities, with falls from heights less than 5 meters accounting for approximately 50% of all fall-related fatalities. Therefore, calculating the lowest point of the safety harness is crucial when considering its use. Previous research assumed that the shock-absorbing device in the lanyard of the safety harness would decelerate fully. Prior studies recommend the lowest position of the safety belt to be 5 meters (Korea) or 17.5 feet (US). Applying these lowest point standards may lead to situations where the lowest point of the safety harness is not maintained during falls from heights under 4 meters, potentially resulting in serious injuries. In the fall experiments, a human-shaped dummy (170 cm tall, weighing 50 kg) was outfitted with a safety harness and dropped from a height of 4 meters. Three different attachment points for the safety harness (30 cm above the head, D-ring position of the safety harness, and below the knee level) and three types of lanyards (elastic, webbing, and rope) were tested. The results showed that both the attachment point of the safety harness and the type of lanyard had a significant impact on the deceleration distance of the shock-absorbing device. Thus, the necessity for a change in the prior method of determining the lowest point of the safety harness, which ignored the attachment point, was identified. This study confirmed that the attachment point is important when calculating the lowest point of the safety harness. Furthermore, it found that a suitable connection point could secure the lowest point of the safety harness, even at low altitudes below 4 meters. Future research should collect more data from experiments conducted under various fall conditions and using different lanyard types to improve the accuracy of safety harness lowest point calculations. These findings are expected to contribute to preventing severe accidents during low-altitude work under 4 meters.