The Ships
SS Mont-Blanc was a 3,121-tonne French cargo ship, unremarkable in every way except for what she was carrying. On 6 December 1917, she entered Halifax Harbour loaded to the gunwales with wartime munitions: 2,366 tonnes of picric acid (used in armour-piercing shells), 226 tonnes of TNT, 62 tonnes of gun cotton, and 246 tonnes of benzol fuel stored in drums on deck. She was, in effect, a floating bomb.
SS Imo was a Norwegian vessel chartered by the Commission for Relief in Belgium to carry supplies to war-ravaged Europe. She was outbound from Halifax, heading into the Narrows — the slim channel connecting the inner harbour to Bedford Basin — at the same time Mont-Blanc was heading in.
The Collision
The Narrows was busy that morning. Through a series of miscommunications, course changes, and violations of the rules of the road, Imo and Mont-Blanc found themselves on a collision course. Mont-Blanc attempted to pass to starboard, Imo signalled she would not yield. At 08:45, Imo's bow struck Mont-Blanc's starboard side, penetrating the hold where the benzol drums were stored.
As Imo reversed engines and pulled free, steel scraped against steel, producing sparks. The benzol ignited.
Twenty Minutes
Imo strikes Mont-Blanc. Benzol drums rupture and catch fire. The crew of Mont-Blanc, knowing what their ship carries, immediately abandon her. They row frantically for the Dartmouth shore, screaming warnings that nobody on the Halifax side can hear.
The burning Mont-Blanc drifts towards Pier 6 in the Richmond district. Crowds gather along the waterfront to watch the spectacular fire. Schoolchildren press against classroom windows. A fire engine races towards the pier. The crew of the naval vessel HMCS Niobe sends a party in a steam pinnace to fight the fire.
Mont-Blanc detonates. The explosion is equivalent to roughly 2.9 kilotonnes of TNT. The ship is vaporised. A blast wave radiates outward at over 1,000 metres per second. The Richmond district — a neighbourhood of 6,000 people — is flattened in an instant. A white column of smoke rises over 6,000 metres into the sky. The blast is heard in Cape Breton, 350 kilometres away.
A tsunami surges through the harbour, rising 18 metres above the high-water mark on the Halifax side. The barrel of one of Mont-Blanc's cannons lands 5.6 kilometres away. Her half-tonne anchor shank flies 3.2 kilometres before embedding in the ground. The shock wave shatters every window in Halifax and damages buildings in Truro, 100 kilometres distant.
Vince Coleman
Vincent Coleman was a telegraph dispatcher at the Richmond railway station, 230 metres from Pier 6. When a sailor from Mont-Blanc ran past shouting that the ship would explode, Coleman and his colleague William Lovett began to flee. Then Coleman stopped. He knew that a passenger train from Saint John, carrying 300 people, was due to arrive at the North Street Station within minutes. He ran back to his telegraph key and sent his warning. The train was stopped at Rockingham, 6 kilometres away. Coleman was killed in the explosion.
The Aftermath
The devastation was almost beyond comprehension. Over 2,000 people were killed outright or died of injuries. More than 9,000 were injured. Roughly 25,000 were left homeless. The entire Richmond district was obliterated. Over 1,600 buildings were destroyed and 12,000 damaged. The explosion blinded hundreds of people — many of them had been watching the fire through windows that shattered inward.
The following day, a blizzard struck Halifax, dumping 40 centimetres of snow on the ruined city and hampering rescue efforts. Survivors were buried alive under collapsed buildings in freezing temperatures.
Relief efforts came from across North America. Boston sent a train loaded with medical supplies, doctors, and nurses almost immediately. The relationship forged in that crisis endures to this day: every December, the province of Nova Scotia sends a massive Christmas tree to the city of Boston as a gesture of gratitude. The tradition has continued unbroken since 1971.
Further Reading
- Wikipedia Halifax Explosion — Wikipedia
- Encyclopaedia Halifax Explosion — The Canadian Encyclopedia
- Encyclopaedia Halifax Explosion of 1917 — Encyclopaedia Britannica
- Museum The Halifax Explosion — Canadian War Museum