15 The Halifax Explosion

Even though Canada is a fairly young country, it has had its share of disasters. From great fires to earthquakes to devastating tornadoes, Canada has seen many a tragedy. The Halifax Explosion, however, was so monumental it is hard to forget. In fact, it goes down in history as the worst human-made explosion before the dropping of the nuclear bombs on Hiroshima and Nagasaki in 1945. It is also considered the deadliest disaster in the history of Canada. On December 6, 1917 two ships collided in the Halifax harbour, with the resulting explosion and tsunami wiping out all of Halifax’s north end and killing close to 2000 people, seriously injuring 9000 people, and leaving 25,000 residents homeless (Kernaghan & Foot, 2011). The shock wave of the explosion was so powerful (moving through the ground at twenty-three times the speed of sound) that it would “crush a person’s internal organs, rupture eyeballs, and shatter eardrums. It [would] snap trees, lampposts, and telephone poles… and level buildings close to ground zero” (Cuthbertson, 2017, para. 12). In fact, the clap of the explosion was heard not only eighty kilometers out to sea by ships but also two-hundred and seventy-five kilometers away on land (Cuthbertson, 2017). The air temperature near the explosion rose to a blistering 5000 degrees Celsius, almost rivalling that of the sun (ibid). Ten minutes after the explosion, a black tar-like rain fell on Halifax. The most heartbreaking news, however, is that the collision itself was completely avoidable. It only occurred due to a number of factors – most of which were attributed to human error.

First and foremost, the cargo carried by one of the colliding ships – theMont Blanc– was highly dangerous. The Mont Blanc, a French freighter, was coming into harbour laden with 2925 metric tons of explosives destined for World War I (Encyclopaedia Britannica, 2020). Since Halifax was the closest North American port to Europe, it regularly saw traffic related to the transatlantic war (Maritime Museum of the Atlantic, 2019). In fact, the ship that the Mont Blanc collided with (the Norwegian Imo) was also on war duty. It was heading to New York to load up on food and clothing for occupied Belgium. At the time of the collision, however, the Mont Blanc was carrying 2300 tons of picric acid, 200 tons of TNT, 35 tons of high-octane gasoline, and 10 tons of gun cotton (History, 2019). Upon ignition from the collision, the cargo turned into a three-kiloton bomb resulting in a 52-foot tidal wave, destroying much of the Halifax harbour and parts of the city (NASA, 2013).

Ultimately though, the main cause of the disaster was human error. Firstly, there was no protocol in place, at the time, for ships to declare their dangerous cargo, so nobody in the harbour was aware of the incoming danger. Nor was there a protocol in place to allow such ships to travel alone through the narrows of the harbour to minimize collisions (Kernaghan & Foot, 2011). In reality, these protocols should have been in place but with the amount of traffic entering and exiting the harbour, it was considered an unrealistic expectation at the time. Furthermore, according to Kernaghan and Foot (2011), the Imo found itself in an awkward position in the narrows due to earlier maneuvers by otherships in the passage – indicating human error on their part as well. The pilot of the Mont Blanc, who survived the blast due to abandoning the ship, later claimed the pilot of the Imowas to blame for the collision, not only for his location in the harbour at the time (where the Mont Blanc should have had the right-of-way) but also for the ship’s excessive speed at the time (ibid). Add to this, the various forms of miscommunications between the two ships, and the disaster was inevitable (NASA, 2013).

The human-made disaster of 1917 in Halifax has not been forgotten – nor will it ever be. Besides numerous museums with exhibitions on the disaster, annual ceremonies, and numerous books written about the disaster, there are daily reminders of the tragedy in the city itself. One example is the time showing on the town hall’s clock tower – stopped forever at 9:05 am, the exact moment disaster struck over 100 years ago. Other reminders include the pieces of metal from the ship that are still being dug up in gardens in and around the Halifax harbour. Yet others include the finding of numerous shrapnel in the felling of older trees. The remains of this great human-made disaster are everywhere, reminding people to be more careful in the future. The question is, will we listen?



Cuthbertson,K. (2017). The Halifax explosion: Canada’s worst disaster. Retrieved March 27, 2020 from https://www.canadashistory.ca/explore/books/the-halifax-explosion-canada-s-worst-disaster

Encyclopaedia Britannica. (2020). Halifax explosion. Retrieved March 27, 2020 from https://www.britannica.com/event/Halifax-explosion

History. (2019). The great Halifax explosion. Retrieved March 27, 2020 from https://www.history.com/this-day-in-history/the-great-halifax-explosion

Kernaghan, L., & Foot, R. (2011). Halifax explosion. Retrieved March 25, 2020 from https://www.thecanadianencyclopedia.ca/en/article/halifax-explosion

Maritime Museum of the Atlantic. (2020). Explosion in the Narrows: The 1917 Halifax Harbour explosion. Retrieved March 27, 2020 from https://maritimemuseum.novascotia.ca/what-see-do/halifax-explosion

NASA. (2013). Kiloton killer: The collision of the SS Mont-Blanc and the Halifax explosion. Retrieved March 27, 2020 from https://sma.nasa.gov/docs/default-source/safety-messages/safetymessage-2013-01-07-ssmontblancandhalifaxexplosion.pdf?sfvrsn=d4ae1ef8_6


Comprehension Questions

Vocabulary Exercises

Academic Writing Exercises

Contextual Grammar Exercises






Icon for the Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License

Real Academic Essays: STEM Copyright © by Hilda Freimuth is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License, except where otherwise noted.

Share This Book