They were used in service through the Mount Royal Tunnel in Montreal until retirement in 1995, operating for 76 years, 7 months and 12 days.

[1] They were classified as a Box-Cab model 0440-E-166-4-GE-228-A by General Electric, delivered new to the Canadian Northern Railway.

They were very similar to 6 units built for the Butte, Anaconda and Pacific Railway, as was the electrification system.

One unit, CN 6713, was retired in 1993 and was then cannibalized for spare parts to supply the remaining class Z-1-a locomotives.

[1] Another, CN 6712, was donated to the Town of Mount Royal, and was stored at that city's municipal garage pending selection of a suitable display site.