Sub-series consists of records created and/or maintained by Canadian Northern companies dealing with property equipment, telegraph and express services and other ancillary enterprises. Because of the speed with which the Canadian Northern expanded from a short prairie line to a transcontinental system it was necessary to construct or acquire all the facilities necessary for the successful operation of such a system in a comparatively short time. For financial, legal or administrative reasons it was often necessary to incorporate these enterprises separately.
To provide rolling stock for the rail lines under construction The Imperial Rolling Stock Company Limited (RG30-III-I-1) was incorporated, to be succeeded by Canadian Northern Rolling Stock Limited (RG30-III-I-2) after the system had been nationalized. Connections between Ontario and Minnesota lines were supplied by The Minnesota and Ontario Bridge Company (RG30-III-I-3) and Rainy River Bridge Company (RG30-III-I-4). Terminal facilities had to be provided in both large and small centres. The most ambitious of these terminals was in Montreal, where Canadian Northern Montreal Tunnel and Terminal Company Limited, later Mount Royal Tunnel and Terminal Limited (RG30-III-I-5) was responsible not only for the construction of a terminal but of a tunnel through Mount Royal. Canadian Northern System Terminals (Limited) (RG30-III-I-6) was responsible for providing terminal and hotel facilities across Canada. Facilities were particularly necessary at the Lakehead, and The Lake Superior Terminals Company Limited (RG30-III-I-7), Canadian Northern Railway Elevator Company (RG30-III-I-8), and The Canadian Northern Coal And Ore Dock Company, Limited (RG30-III-I-9) provided these at Port Arthur.
In addition to normal railway services, express services were provided by Canadian Northern Express Company (RG30-III-I-10) while transfer and cartage was the responsibility of The Canadian Northern Transfer Company, Limited (RG30-III-I-11). The capital stock of these two companies was held by The Canadian Northern Railway Express Company Limited (RG30-III-I-12).
The Canadian Northern operated a very extensive telegraph system. In addition to its own company, The Canadian Northern Telegraph Company (RG30-III-I-13) it acquired, in 1915, control of The Great North Western Telegraph Company of Canada (RG30-III-I-16). The latter company represented the Western Union system of the U.S. in Canada and had acquired, in the course of its expansion, control of other Canadian systems. These included one of the oldest Canadian telegraph companies, Montreal Telegraph Company (RG30-III-I-14) which, in its early existence had absorbed the Montreal and Troy Telegraph Company (RG30-III-I-15).
