Canadian Railway Hall of Fame -

Centralized traffic control is a means of controlling railway movements through signals and switches remotely controlled by a train dispatcher at a central office. The system is partially automated, in that only one train at a time can be given signal permission to occupy of a block of track, and that signals never permit operating over a diverging switch at an unsafe speed.

Centralized traffic control greatly increases the capacity and safety of a railway line, especially compared to the older system where trains were authorized by complicated time tables modified by written messages picked up by train crews at stations along their trip. However, the system was mainly a theoretical concept in the 1920s and 1930s, having been implemented only on a few short sections scattered around North America. It had never been installed on long stretches of mainline.

In the early years of the Second World War, the Dominion faced a transportation crisis. The United Kingdom was depending on vast shipments of food and matériel from Canada, and large numbers of Canadian sailors, soldiers and airmen were moving overseas as well. The activities of German submarines were threatening to block the Gulf of St. Lawrence and cut off the port of Montréal. Military personnel could not travel on the Canadian Pacific Railway to the Maritimes, as the line passed through the United States, which was neutral at the time. Canadian National’s line from Moncton to Halifax was becoming the narrow end of a nation-wide funnel, and the demands on it were starting to exceed its capacity. Something had to be done, quickly.

The railway had two ways to increase capacity. First, it could build a second main track. This would be almost as big an engineering challenge as the initial construction and would consume a lot of labour, steel and other matériel needed for the war effort; however, it was proven technology and would certainly alleviate the capacity problems. The second choice would be to install centralized traffic control. This would use less labour and steel, but the choice was fraught with risk. As no one had undertaken such a project before, no one could safely predict how long it would take, how well it would work or how much it would increase the line’s capacity.

Canadian National Railways undertook the risk, and through the diligent efforts of a dedicated team, centralized traffic control was installed on a 160 km section of the worst part of the bottleneck — Moncton, New Brunswick, to Truro, Nova Scotia — in only six months. The results were immediate: the capacity of the line improved nearly as much as what double tracking would have provided, but at only a small fraction of the cost and in a small fraction of the time. Trans-Atlantic shipping out of Halifax was able to meet the demands and keep the United Kingdom in the war until the tide was turned.

The success of this centralized traffic control project was a great contribution towards victory and the peace we have enjoyed for most of the last fifty years, and therefore we are pleased to induct centralized traffic control into the technology category of the Canadian Railway Hall of Fame.