25 kV A.C. conversion, Liverpool Street to Gidea Park E.R. current collection performance of a triple contact wire bridge arrangement and the Brown Boveri section insulator tested at Widmerpool May '77 (TM-ETR-98)

The Liverpool St.-Shenfield line was originally electrified in 1949 at 1 500 V d.c., using heavy compound fixed-termination overhead equipment. It was converted to 6.25 kV a.c. in 1960, retaining the original bridge arrangements except for larger insulators. The Gidea Park-Shenfield section, which has few bridges, has been converted to...