The six half train Advanced Passenger Trains sets emerged in 1978-79 to undergo development running on the Euston-Glasgow route, the sets were a development of the gas-turbine powered APT and were constructed to test, refine and give passenger trials tilting train technology.
The six half sets, formed into three passenger rakes carried out a number of trial runs on the WCML but serious design faults with the train and cant system saw massive delays to the project. Eventually by the mid-1980s after some high profile media coverage of the train failing on its press launch train the project was eventually finished. One half set of APT vehicles, with two driving cars is now preserved at the Railway Age, Crewe.