ASCE Manual No.74 (2010) and the Electric Power Research Institute (EPRI, 1997) provide methods for calculating the unbalanced longitudinal loads on a transmission line due to a wire breakage. The calculated loads from the two are different. In this study, a simplified transmission line was created using the equivalent geometric properties of a detailed transmission line. Non-linear dynamic analyses of the 10-span simplified transmission line due to cable breakage events in the first span were studied using ANSYS. The analyzed longitudinal loads were found to vary for different S/S, S/I, and K’s as specified in the EPRI. An equation for the longitudinal load factor as a function of the S/S, S/I, and K was then formulated based on the analysis. The longitudinal load factors from the formulated equation were found to be almost double those given by the ASCE manual and comparable to those calculated using the EPRI formulation.

ASCE Manual No.74 (2010) and the Electric Power Research Institute (EPRI, 1997) provide methods for calculating the unbalanced longitudinal loads on a transmission line due to a wire breakage. The calculated loads from the two are different. In this study, a simplified transmission line was created using the equivalent geometric properties of a detailed transmission line. Non-linear dynamic analyses of the 10-span simplified transmission line due to cable breakage events in the first span were studied using ANSYS. The analyzed longitudinal loads were found to vary for different S/S, S/I, and K’s as specified in the EPRI. An equation for the longitudinal load factor as a function of the S/S, S/I, and K was then formulated based on the analysis. The longitudinal load factors from the formulated equation were found to be almost double those given by the ASCE manual and comparable to those calculated using the EPRI formulation.