Editing Advanced Passenger Train (section)

==Legacy==
Alan Williams<ref name= williams>Williams (1985)</ref> notes that work continued on a new variant, the APT-U (APT-Update). This was essentially APT-P with the tilt system made optional and the engines repositioned at either end of the train with power couplings running between them. That project was later retitled [[InterCity 225]] (IC225), perhaps to distance it from the bad publicity surrounding the APT-P. The [[British Rail Mark 4|Mark 4]] coach design that was introduced as part of the new IC225 sets for the [[East Coast Main Line]] electrification allowed the retrofitting of the tilt mechanism, although this was never implemented. The [[British Rail Class 91|Class 91]] locomotives that power the IC225s had design features "imported wholesale" from the APT-P power cars, including body- rather than bogie-mounted traction motors to reduce unsprung load, and having the transformer below rather than on top of the underframe to reduce the centre of gravity. Unlike the APT-P power cars, though, they were never intended to tilt.<ref>"The Design and Development of the Class 91 Locomotive", P J Donnison and G R West, Main Line Railway Electrification Conference 1989 - Proceedings of the Institute of Electrical Engineers, 1989.</ref><ref>"The design, manufacture and assembly of the British Rail Class 91, 25 kV 225&nbsp;km/h locomotive", M L Broom and G W Smart, Proceedings of the Institute of Mechanical Engineers Vol. 205, 1990.</ref>
 
In 1976 [[Fiat Ferroviaria]] built the ETR 401 trainset, a tilting train using an active system with 10 degrees of tilting that used gyroscopes to detect the corner in its early phases in order to have a more punctual and comfortable inclination: this is why the FIAT project has been successful since the '70s. In 1982 FIAT bought some APT patents that were used to improve their technology for the ETR 450 trainsets.<ref name=manufacturer>{{Cite web |url=https://www.smartrailworld.com/the-twisting-and-turning-tale-of-britains-tilting-trains |title=The twisting and turning tale of Britain's tilting trains. |access-date=25 October 2017 |archive-url=https://web.archive.org/web/20171026054400/https://www.smartrailworld.com/the-twisting-and-turning-tale-of-britains-tilting-trains |archive-date=26 October 2017 |url-status=dead}}</ref>

The introduction of the Squadron fleet designated APT-S did not occur as had been originally envisaged. The APT project succumbed to an insufficient political will in the United Kingdom to persist in solving the teething difficulties experienced with the many immature technologies necessary for a groundbreaking project of this nature. The decision not to proceed was made against a backdrop of negative public perceptions shaped by media coverage of the time.<ref name = potter>Potter (1987){{page needed|date=August 2012}}</ref><ref name = gourvish>Gourvish (2004), Chapter 3: ''Operations, Productivity and Technological Change''.{{page needed|date=August 2012}}</ref> The APT is acknowledged as a milestone in the development of the current generation of tilting high speed trains.{{citation needed|date=August 2012}} 25 years later on an upgraded infrastructure the Class 390 Pendolinos now match the APT's scheduled timings. The London to Glasgow route by APT (1980/81 timetable) was 4hrs 10min, the same time as the fastest [[Pendolino]] timing (December 2008 timetable).

In 2006, on a one off non-stop run for charity, a Pendolino completed the Glasgow to London journey in 3hrs 55min, whereas the APT completed the opposite London to Glasgow journey in 3hrs 52min in 1984.<ref>{{Cite news |url = http://news.bbc.co.uk/1/hi/scotland/glasgow_and_west/5369808.stm |title = Virgin train breaks speed record |work = [[BBC News]] |date = 22 September 2006 |access-date = 29 July 2012 |archive-url = https://web.archive.org/web/20120313133208/http://news.bbc.co.uk/1/hi/scotland/glasgow_and_west/5369808.stm |archive-date = 13 March 2012 |url-status = live}}</ref>

On 17 June 2021, a Pendolino named Royal Scot and operated by Avanti West Coast ran an attempt to beat the record but fell short of the record time by only 21 seconds.  The nine-carriage train travelled non-stop at an average speed of 103&nbsp;mph on the 401-mile route.<ref>{{cite news |title=Train fails to beat 36-year-old London-Glasgow record by 21 seconds |url=https://news.sky.com/story/train-fails-to-beat-36-year-old-london-glasgow-record-by-21-seconds-12335056 |access-date=19 June 2021 |publisher=Sky News}}</ref>

Continued analysis of the data collected during the project led to a better understanding of the causes of track wear and the need to reduce unsprung mass rather than reduce the overall weight of the carriage. This led to the development of the [[BREL P3/T3]] for the [[British Rail Class 365]] and [[British Rail Class 465]], which among other improvements featured smaller radius wheels. BREL further developed the concept to produce the [[Advanced Suburban Bogie]] which was a factor in [[ABB]] acquisition of BREL.<ref>{{cite web | url=https://zhuanlan-zhihu-com.translate.goog/p/55325165?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=en-US&_x_tr_pto=wapp | title=The Past and Present of ICE 4 (ICx) Trailer Bogies - A Brief History of B-5101 Typ Flexx Eco IC }}</ref>