Validation of the energy balance approach for design of vertical lifeline systems

To ensure that vertical lifeline systems (VLLSs) are well designed, calculation methods are required to estimate the extension of a personal energy absorber (PEA) (x_PEA) and the total fall distance (h_TFD). Thus, the authors conducted 28 tests to validate the accuracy of the energy balance approach for estimating x_PEA and h_TFD of VLLSs and propose suitable correction factors to improve the accuracy and safety of the estimated x_PEA and h_TFD. For 9 out of 19 tests with a PEA, the difference between the theorical x_PEA and empirical x_PEA was 25% or higher, indicating that the energy balance approach is not accurate for estimation of x_PEA. In contrast, theoretical values of h_TFD are more accurate. Linear regression equations for estimating x_PEA (R² = 0.81) and h_TFD (R² = 0.99) were developed. The regression equations can be used to improve the accuracy and conservativeness of estimations of x_PEA and h_TFD during the design of VLLSs.