Exercise Tocsin B | The Canadian Encyclopedia


Exercise Tocsin B

Exercise Tocsin B was a nationwide nuclear preparedness drill that lasted 24 hours between 13 and 14 November 1961. It was the last of three national survival exercises named Tocsin in 1960–61. It was also the largest and most widely publicized civil defence drill ever held in Canada. This Cold War exercise run by the Canadian Army simulated the impact of thermonuclear warfare in Canada. Its goals were to show how the state would warn Canadians of such an attack and how government would continue during the crisis. By raising popular awareness of the potential for a devastating nuclear attack, Tocsin B showed Canadians what was at stake in the Cold War.


Exercise Tocsin B was based on an imaginary bomber and missile attack by an unidentified enemy. The immediate effects of the nuclear blast would kill more than 2 million Canadians and injure another 1 million or more. In this scenario, five-megaton nuclear weapons hit 14 of Canada’s largest cities and destroyed six air force bases. Windsor, Ontario, was annihilated by a 10-megaton weapon aimed at Detroit.

While the public received some advance notice of Tocsin B, it did not know exactly when the drill would start. The sounding of air-raid sirens at 7:00 p.m. Eastern Standard Time on 13 November 1961 (a Monday) came as a great surprise to most Canadians.

Did you know?
The word tocsin, which dates back to the 16th century, refers to the alarm sounded by village church bells to warn of imminent attack.

Continuance of Government

Public survival was the ultimate goal of civil defence in Exercise Tocsin B. However, “continuance of government” was its immediate goal. This is because effective government was viewed as vital to public survival. To continue to govern after a nuclear holocaust, cabinet ministers and key officials at all levels would have to evacuate the target cities. The drill had them travel to remote emergency headquarters. From there, they could direct survival operations.

The federal Cabinet and deputy ministers relocated from Ottawa to Camp Petawawa. This army base became Canada’s capital for the next 24 hours. Each provincial government also moved from its capital to a secure headquarters. For example, Premier Robarts and Ontario’s Cabinet left Queen’s Park for Camp Borden. For the rest of the exercise, the federal, provincial and municipal governments of Canada were active. They attempted to run the country and operate all essential services from their remote headquarters. This also meant dealing with massive nuclear casualties and widespread destruction of buildings, transportation arteries and communications links.

Public Survival

By 1961, ballistic missiles were the most likely method of nuclear attack. These would be launched from submarines or bases on land. Unlike the piloted bombers feared in the 1950s, missiles could arrive with little warning. Thus, the evacuation plans of the 1950s gave way to blast and fallout shelters. Rapid response by civilians was essential to nuclear preparedness.

In this context, Tocsin B’s strategy to ensure public survival was to communicate an urgent message across the country. The message would reach communities both large and small, urban and rural. It had three components: air-raid sirens, public broadcasting and local initiatives.

To alert all within earshot, some 500 air-raid sirens across the country were to sound at the same time. This part of the drill had mixed results. The number of people frightened by the sirens surprised civil defence staff. In Toronto, the police and local Emergency Measures Organization staff received hundreds of anxious phone calls from people unaware of the exercise. Some sirens, including Oshawa’s, failed to sound. West Vancouver’s siren short circuited, causing a fire. Smaller centres such as Portage la Prairie did not yet have sirens. In Montreal, many complained that the sirens were inaudible.

Illustration showing an air-raid siren, a man delivering a radio broadcast, and people listening to the radio while taking shelter in a home

Illustration from a pamphlet titled 11 Steps to Survival, published by the Canada Emergency Measures Organization in 1969.

The novelty of a televised message from Prime Minister John Diefenbaker brought the gravity of the test into focus. His broadcast informed Canadians of what to expect in the case of nuclear war: “My fellow Canadians, you have just heard the siren sound the national alert. This is an exercise and a test. All of us pray that it will never be required as a reality. But if war comes, the alert warning would mean that the continental air defense system had detected and identified a likely attack on North America.” The exercise also included emergency broadcasts on all radio stations.

Local government was tasked with delivering basic services to Canadians. This is how 2,000 blankets would reach the homeless of Windsor, Ontario, for example, and how Cold Lake, Alberta, would treat its drinking water.

Federal government services were to reach each community through the post office network (see Postal System). Postal facilities had stockpiles of cards to help coordinate survival efforts. Ration cards would help manage food distribution. Blue change-of-address cards would help ensure that those whose homes were destroyed would still receive federal social services such as family allowance cheques. Pink notice-of-survival cards would reassure traumatized families and friends.

Reception and Impact

Most observers believed that Exercise Tocsin B was a successful measure of the enormous challenges that Canada would face in the wake of nuclear attack. The exercise showed some of the gaps in coverage by Canada’s network of air-raid sirens. Federal, provincial and municipal officials gained a vivid impression of the real challenges of maintaining intergovernmental coordination if a nuclear attack were to destroy much of the nation’s communication and transportation infrastructure.

The exercise was controversial, and the lessons learned were a matter of debate. Continuity of government prioritized the health and safety of politicians and bureaucrats. This priority seemed self-serving to a public concerned about survival in the aftermath of a nuclear holocaust.

In the days after Tocsin B, the press reported that Prime Minister Diefenbaker had refused to be evacuated to Camp Petawawa. Officials therefore changed the scenario to presume his death. (Governor General Georges Vanier was also “killed” in the attack on Ottawa.) At Camp Petawawa, Defence Minister Douglas Harkness became acting prime minister for the purposes of the exercise. In a debate months later, Judy LaMarsh of the Liberal opposition criticized Diefenbaker for “sitting with his dog on his lap and his wife’s hand in his hand, in his own home” during Tocsin B.

Judy LaMarsh
This postage stamp issued in 1997 commemorates Judy LaMarsh’s public service. As Minister of National Health and Welfare from 1963 to 1965, LaMarsh was faced with implementing the Royal Commission on Health Services’ recommendations when other priorities claimed government attention.
(Library and Archives Canada/e000008900)

Opposition leader Lester Pearson highlighted the differences in privilege that left Canadians with unequal safeguards for nuclear survival. Some homeowners could build their own fallout shelters. Many people who were less fortunate, however, would need access to collective shelters. Officials considered converting urban structures (e.g., the Toronto subway and underground parking garages) to public shelters. However, different levels of government remained stuck debating who should fund such projects. Further, Diefenbaker’s “death” in the bomb shelter he had built at 24 Sussex Drive led to doubts about the effectiveness of shelters. Governments stopped promoting the construction of home bomb shelters a few years later.

The Diefenbunker was completed soon after Tocsin B. It was a secure emergency headquarters for the federal government that was closer to Ottawa than Camp Petawawa. Less than a year after the drill, the Cuban Missile Crisis showed that Cold War tensions and the possibility of nuclear war were real. Other planning and administrative exercises followed, including the low-profile Tocsin ‘66 from 12 to 21 October 1966. However, civil defence was waning as a national priority. Tocsin B remains significant as the most widely reported of all the nuclear preparedness drills. It was the last time that air-raid sirens sounded their eerie warning from coast to coast.

Further Reading

External Links