Starting in the late 1960s, British Rail also began experiments with its Advanced Passenger Train (APT) which pioneered the active-tilt concept, along with in-cab signalling, to permit High Speed Rail services on conventional tracks. The APT family used hydraulic rams on the bottoms of the carriages to tilt them, rotating them around their centre point rather than swinging outward. This had the advantage of keeping the carriage centred over the bogies, which reduced load on the rails, and could be turned off when navigating switches. Due to lengthy political delays, the APT did not begin service testing until 1979, entering limited scheduled service in December 1981, the media describing the initial revenue run as both fifteen years late, and the queasy rider; the sets only briefly entering full revenue operation in 1985, before being withdrawn and the associated technologies sold to Alstom / Fiat Ferroviaria. By this time, the Canadian LRC design had become the first active tilting train to enter full commercial service, starting with Via Rail in 1981.
Starting in the late 1960s British Rail also began experiments with its Advanced Passenger Train (APT) which pioneered the active-tilt concept along with in-cab signalling to permit High Speed Rail services on conventional tracks The APT family used hydraulic rams on the bottoms of the carriages to tilt them rotating them around their centre point rather than swinging outward This had the advantage of keeping the carriage centred over the bogies which reduced load on the rails and could be turned off when navigating switches Due to lengthy political delays the APT did not begin service testing until 1979 entering limited scheduled service in December 1981 the media describing the initial revenue run as both fifteen years late and the queasy rider; the sets only briefly entering full revenue operation in 1985 before being withdrawn and the associated technologies sold to Alstom / Fiat Ferroviaria By this time the Canadian LRC design had become the first active tilting train to enter full commercial service starting with Via Rail in 1981