As of May 2011, the H4 class became the longest-serving class of subway cars operated in Toronto, serving for more than 36 and-a-half years, surpassing the M1 cars and the Gloucesters. The class wasn't able to bask in this honour for long.

The Hawker Siddeley Canada H4 was a type of subway car built for the Toronto Transit Commission. They were classified as H4 by the TTC, but were based on the common Hawker Siddeley RT75 design of previous cars.

Toronto Transit Commission 5576-5663 were Hawker Siddeley Canada H4 subway cars delivered between September 1974 and December 1975. The cars were ordered for expansion to provide more service in the wake of the North Yonge subway extension opening.

With the arrival of the articulated TR trains in 2011, many T1-series trains were transferred from the YUS line to the Bloor–Danforth line. This allowed for the retirement of the H-4 cars, between the fall of 2011 until January 27, 2012, when the last H-4 train made its last run during the morning rush on the Bloor-Danforth line. [ 7 ]

In spring of 2011, the Toronto Transportation Society approached the TTC to do a farewell charter to the H-4 subway trains which were due to be retired by the end of 2011 with the Toronto Rocket subway trains entering service. The H-4s are the longest running subway cars on the TTC network running for 40 years!

With the arrival of the articulated TR trains in 2011, many T1 series trains were transferred from the YUS line to the Bloor–Danforth line. This allowed for the retirement of the H4 cars, between the fall of 2011 until January 27, 2012, when the last H4 train made its last run during the morning rush on the Bloor-Danforth line. [6]

2015年5月1日 · In June 2013, the TTC converted an H4-class car into a general work car, numbered RT-38 (purchased in 2011). It was mated with Arva Industries flatcar RT-39. Chris Edwards took this photograph at Davisville station on June 8, 2018.

2012年6月16日 · Upon receipt of the Toronto Rocket trains in late 2011, the H4 trains have gradually been replaced with the T1 series of trains, sent over from the Yonge-University-Spadina Line.

2019年4月27日 · Numbered 5602 and 5647, the two Hawker-Siddeley Canada H4 cars entered service in 1974 and retired in late 2011 — just a few months before the entire fleet was taken out of service in January...