Construction on Canada's first subway began in early September 1949. The 4.6 mile Yonge Street line, running south from Eglington Avenue to Toronto's Union Station on Front Street, officially opened March 30, 1954. 100 cars, in two-car married pairs numbered 5000-5099, were delivered in 1954 by the Gloucester Railway Carriage and Wagon Works (England). These cars were painted red. Six similiar cars of aluminum construction were delivered by the same builder later in 1954-55. These last six cars, 5100-5105, were not painted.

Cars 5098-5099 lead the officials train to open the subway line and are now at the Halton County Radial Railway, Milton, Ontario. Since it is not safe for third rail operation at the museum, a trolley pole was installed on the roof of each car.