Dynamic-model studies of overhead equipment for electric railway traction. Sagged stitched- and compound-catenary equipment and further tests on sagged simple-catenary equipment

An account is given of the use of dynamically scaled models for predicting the behaviour of overhead equipment for railway electrification at 25 kV. The effects of varying the contact-wire sag and other dimensions of model compound- and stitched-catenary equipments have been measured. The maximum permissible speeds on equipment with the optimum sag were found to range from 200 to 224km/h (125 to 140 mile/h) when a single, undamped pantograph was used. Tests on model sagged simple-catenary equipment have also shown that a speed of 160km/h (100 mile/h) is still permissible even when large errors exist in the conductor tensions or when the droppers are to some degree incorrectly set.