Based on the 75 ft (22.86 m) M1, the early H-series cars improved on the design, notably by enlarging the operator's cab and using a single-handle controller.
Revisions were made to the designs, and each production model in the H series improved on the last.
The H5s were the first subway cars in the TTC fleet to use "chopper controls" and were also the first cars with regenerative braking and air-conditioning systems.
They had a brighter and more modern passenger interior.
Black vinyl seats were replaced by red fabric seats.
Individual seats replaced the padded bench seats used on previous models.
The interior colour scheme consisted of red floors, cream walls, yellow doors and panels, and brown simulated wood grain panels.
The H6s replaced the original red G-class cars and were used almost exclusively on the Bloor-Danforth line, with no further H-Series orders made.
The H6s were similar to the H5s, but had light brown floors, and orange doors and panels.
A prototype T-series car was built by UTDC in 1990–1991, and evaluated by the TTC.
By the time the TTC was ready to order new cars in 1992, UTDC had been sold to Bombardier.
Bombardier added new technology such as AC propulsion to a platform based on the predecessor H-cars.

48 cars based on the H1 model were built and used for the Expo Express in Montreal, Quebec for Expo 67.

108 modified H6 cars were produced for the Ankara Metro by Bombardier in 1996–1997.
Based on the 75 ft (22.86 m) M1, the early H-series cars improved on the design, notably by enlarging the operator's cab and using a single-handle controller. Revisions were made to the designs, and each production model in the H series improved on the last. The H5s were the first subway cars in the TTC fleet to use "chopper controls" and were also the first cars with regenerative braking and air-conditioning systems. They had a brighter and more modern passenger interior. Black vinyl seats were replaced by red fabric seats. Individual seats replaced the padded bench seats used on previous models. The interior colour scheme consisted of red floors, cream walls, yellow doors and panels, and brown simulated wood grain panels. The H6s replaced the original red G-class cars and were used almost exclusively on the Bloor-Danforth line, with no further H-Series orders made. The H6s were similar to the H5s, but had light brown floors, and orange doors and panels. A prototype T-series car was built by UTDC in 1990–1991, and evaluated by the TTC. By the time the TTC was ready to order new cars in 1992, UTDC had been sold to Bombardier. Bombardier added new technology such as AC propulsion to a platform based on the predecessor H-cars.
48 cars based on the H1 model were built and used for the Expo Express in Montreal, Quebec for Expo 67.
108 modified H6 cars were produced for the Ankara Metro by Bombardier in 1996–1997.
H series (Toronto subway)