Development in protection for 25 kV AC electrified lines on British Railways

There is little doubt that the protection equipment installed in the late 1950s and 1960s has stood the test of time, despite the harsh railway environment. This is a result of sound basic design and the continuous preventative maintenance of the equipment. Thirty years on, the implications are being considered of a strategy to replace life expired protection equipment or continue with the current maintenance programme and accept the ever increasing risk of failure and its consequences. This paper briefly describes some of the current issues affecting the British Railway´s protection system by discussing its history, its present state and what developments we can look forward to in the near future