The development of and field tests on different types of high-voltage overhead traction equipment

With the increase in the high-voltage overhead-contact system of railway electrification throughout the world in the past 10 years it has become increasingly necessary to investigate in greater detail the problems associated with current collection, particularly with the lighter overhead equipment used in this system and the higher train speeds possible with electrification. These problems have been dealt with in connection with the 25 kV a.c. electrification schemes in British Railways by the design of overhead equipment to meet the particular requirements and also by the development by the London Midland Region of a specially instrumented high-speed test car capable of measuring all the factors influencing current collection.