The Collision

On December 5, 1917 SS Mont-Blanc, a tramp steamer, arrived in Halifax loaded with munitions in her hull. Her cargo consisted of TNT, Benzole, guncotton, and picric acid. She was to meet up with a convoy heading to Bordeaux, France the next day.

At 7:30 am on December 6, 1917, Francis Mackey, an experienced harbor pilot, started moving the SS Mont-Blanc towards Bedford Basin keeping a close eye out for the ferries and other small boats. He first spotted the SS Imo when she was about 1.21 kilometers away and it too was outbound. The pilot became concerned as the SS Imo's path seemed to be heading towards the SS Mont-Blanc. MacKey gave a short blast on his horn, which meant that he had the right of way. The SS Imo gave two short blasts of its horn meaning the Imo would not yield her position. At this point the captain of the SS Mont-Blanc cut its engine speed to half and maneuvered slightly starboard towards the Dartmouth side of the narrows. The SS Mont-Blanc gave another short blast of its horn, but the SS Imo again replied with two short blasts of its horn. The two vessels were moving towards each other and both captains cut there engines, but too late. At 8:45 am the two ships collided. The collision, although slow enough not to breach the hull of the SS Imo did breach the hull of the SS Mont-Blanc and had enough force that barrels of Benzole on the deck were crushed and sprang leaks where it made its way below decks and over the side railings. As the SS Imo started to disengage from the SS Mont-Blanc it created sparks that caught the Benzole alight. The fire quickly spread and started to make its way into the hold of the SS Mont-Blanc. The captain gave the order to abandon the ship and for the next 10 to 15 minutes the SS Mont-Blanc drifted towards pier 6 near Richmond street where it grounded itself. Huge columns of thick black smoke could be seen and many people ran to their windows and outside to get a better view.

Their Fate Was Sealed

At 9:04:35 am the fire finally reached the explosives. The blast blew the SS Mont-Blanc apart in the largest non-nuclear explosion the world had ever seen. It was the equivalent of 2,400 metric tons or about 4,800,000 pounds of TNT!
The blast instantly killed 1,600 people and left another 9,000 maimed and injured. Parts of the SS Mont-Blanc landed miles away and molten metal rained down over the city. The shockwave travelled away from ground zero at 3,300 feet per second. The heat at ground zero reached over 9,000 degrees F and the pressure reached thousands of atmospheres. The ocean floor was exposed and a tsunami was created as water filled the void. 400 acres of the city was instantly demolished. The explosion caused a cloud of smoke that rose to over 11,000 feet in the air. Over 2,000 people lost their lives that day.

Almost every window in the city was shattered by the shock wave.

A Hero Emerges

Patrick Vincent (Vince) Coleman, who worked for the Intercolonial Railway, started to flee from his post near pier #6 when he remembered that a train was due in within minutes. He rushed back to the telegraph in his office and quickly sent out messages to stop the train: "Hold up the train. Ammunition ship afire in harbor making for Pier 6 and will explode. Guess this will be my last message. Good-bye boys." The train stopped and his actions saved 300 people aboard it.

The devastation in the aftermath

Part of the SS Mont-Blanc's anchor that landed 2 miles away!

Thanks to Wikipedia and to military.wikkia

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