HomeNova ScotiaThe Halifax Explosion of 1917

The Halifax Explosion of 1917

In many ways December 6th, 1917 was a typical early winter day in Halifax .  The sun was bright in a clear sky and the ground was clear of snow. A light haze hung over the harbor, but visibility was generally very good. But what started out as a typical day did not end that way.  That day became the most notorious day in the history of Halifax. That’s the day of the Halifax Explosion.

The Halifax Harbor is considered one of the finest and safest harbors in the world. It reaches far inland from the Atlantic Ocean.  The harbor is protected from the fierce ocean.  In times of war (in 1917 the First World War was still raging in Europe), it protected merchant ships from the marauding German U-boats. Because the war effort included shipping large amounts of material to Europe, and because of  its strategic location in North America, Halifax became the staging point for many trans-Atlantic convoys.

Halifax Harbor during Explosion of 1917

Halifax Harbor

One ship which arrived to the Halifax Harbor was the Mont Blanc.  She arrived from the New York Harbor too late on December 5 to enter the harbor that day. In the early evening the harbour-master raised a large chain across the mouth of the harbor to keep out U-boats.  At 07:30 on the 6th she raised anchor to sail inland.

At the same time as the Mont Blanc sailed in, a second ship – the Imo  prepared to leave port and head to the open ocean.

The Mont Blanc, a French steamer, was 330 feet long and 40 feet wide. Her cargo of explosives was bound for the fighting in Europe by way of Bordeaux, France. And what a cargo it was.  The manifest of the Mont Blanc reads like a chemistry experiment:

  • 2300 tons of wet and dry picric acid.
  • 200 tons of TNT.
  • 35 tons of benzol (stored on the open decks).
  • 10 tons of gun cotton.

You better believe that there were more than a few no-smoking signs on that ship!

Shipyard at Halifax Nova Scotia Explosion of 1917

Halifax Explosion 1917

The Imo, 430 feet long and 44 feet wide, was heading for New York after its trip from Holland. She traveled as a neutral vessel and had no explosive material or guns on board.

(You can read more about the details of why these two ships collided on that fateful day in December. Our role at Mysteries of Canada is to highlight the story not the details.)

Through a series of mixed signals, the Imo appeared to be sailing in the right-of-way of the Mont Blanc. The Mont Blanc gave a short blast of its signal whistle to let the Imo know that it had the right-of-way. The Imo, to the surprise of the Mont Blanc, signaled its intention to turn to port, putting it further into the path of the Mont Blanc. A flurry of more signals ensued and eventually the collision to place mid-stream right next to one of the busiest wharves in Halifax.

The collision ruptured the benzol barrels on deck and caused a leak into the hold containing the picric acid. A fire began, spewing thick black smoke into the clear sky.

Map depicting the location of Halifax Explosion of 1917

Map of Halifax Explosion

Knowing the fate of the Mont Blanc, the captain and crew abandoned ship and rowed to the Dartmouth shore. The Imo was only slightly damaged and, not knowing the cargo on the Mont Blanc, its crew remained with the ship.

At 09:05 the Mont Blanc exploded with the power of a volcano. 3000 tons of steel shattered and a mini-tidal wave fanned out from the spot. The explosion was so violent that a one of the Mont Blanc‘s guns flew over 3.5 miles before coming to rest in Dartmouth. An anchor, weighing 1140 pounds landed some 2 miles away at Armdale.

The toll of the Halifax Explosion was enormous with over 1600 men, women and children killed. An additional 9000 people were injured and  25,000 buildings spread over 325 acres were destroyed.

1917 Halifax Explosion image of destroyed ships and land.

Aftermath of the 1917 Halifax Explosion

Communications links with the outside world were destroyed by the explosion which made the relief effort even more difficult.

Telegram from the Halifax explosion of 1917


Many books have been written on the subject of the Halifax Explosion. There are miraculous stories of people whose lives were spared by strange circumstance and stories of individual and collective heroism in the face of the disaster.

We urge you to read about this great Mystery of Canada.

Especially read Black Snow by Mysteriesofcanada.com contributor, Jon Tattrie.

Jon Tattrie Black Snow

Jon Tattrie

The Halifax Explosion of 1917
Article Name
The Halifax Explosion of 1917
In many ways it was a typical early winter day in Halifax – that December 6, 1917. That’s the day of the Halifax Explosion.
Publisher Name
Mysteries of Canada
Post Tags -

Written by

Author of Mysteries of Canada

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.