25 kV trackside vacuum and SF6 switchgear on Britain´s railways

This paper examines the development and use of 25 kV single phase vacuum and SF₆ trackside switchgear on Britain´s Railways. 25 kV switchgear has been in use on the railway electrification system for more than 35 years. Initially this took the form of bulk oil switchgear but in the late 1960s there was significant interest in the potential use of new switchgear technology on the railway system. The author discusses the progression to vacuum switchgear, and then to SF₆ switchgear in the 1990s