The Halifax Explosion 1917

The explosion in Beirut should have reminded Canadians of our own tragedy, the great Halifax explosion which occurred December 6th, 1917. Wikipedia has a good detailed article which I will attempt to abstract and illustrate with maps from several sources https://en.wikipedia.org/wiki/Halifax_Explosion.

Halifax was a major stopping off point between Europe and New York. The harbour was relatively safe as submarine nets protected it at night and were lowered to allow ships in and out in daylight. The inner harbour, Bedford Basin, was the main anchorage where merchant convoys were put together. The Narrows separated Bedford Basin from Halifax Harbour. 

Ships navigating the narrows were to keep to the right with the oncoming ship to their left. Speed was limited to 5 knots or 9.3 kmph. Ship traffic was very high and rules were sometimes ignored in the name of speed. The Harbour Master informed the authorities that he could no longer guarantee the safety of ships in the harbour.

Map of Halifax Harbour, the Narrows and Bedford Basin

The SS Imo was a Norwegian ship headed for New York to take on relief supplies for Belgium. Anchored in the Bedford Basin, she did not finish loading coal until after the submarine nets had been raised on December 5th and was stuck there until morning. The SS Mont Blanc was a French ship taking explosives from New York to France via Halifax. She carried 2,925 tonnes of explosives—including 62 tonnes of guncotton, 246 tonnes of benzol, a highly flammable liquid, 250 tonnes of TNT, and 2,367 tonnes of picric acid. She arrived too late to enter the harbour December 5th. No one was aware of the load she carried and though she asked for special protection, it was not given. 

Why the collision occurred

When the Imo was given permission in the morning to leave Bedford Basin, she set out fast to make up time but was forced to her left by oncoming boats. The incoming Mont Blanc, moving slowly signalled the Imo to move over but was initially refused. The Mont Blanc swerved hard left to avoid a collision just as the Imo also swerved right. The two ships collided and sparked ignited the spilled benzol. Firefighters rushed to control the flames, not knowing of the danger and 20 minutes after the collision at 9:05 am, the Mont Blanc exploded.

The area totally destroyed by the explosion

The explosion killed at least 1950 people and injured another 9,000. Thousands of people had stopped to watch the ship burning in the harbour. The explosion destroyed the north end of Halifax, left 6,000 completely homeless and 25,000 with insufficient shelter in damaged homes. A raging blizzard the next day helped put out the fires but hampered rescue efforts. 

Help came by train from all over Nova Scotia and elsewhere. Damages were estimated at $31million and about $30 million was raised from a number of sources including $750,000 from the Commonwealth of Massachusetts.

One story I read some time ago, not mentioned in the Wiki article, was of a telegraph operator who stayed at his station frantically trying to reach the night passenger train from St John which would be pulling into Halifax at this time. He managed to stop the train just short of the damage zone but lost his life in the explosion.

Halifax was rebuilt and international rules about identifying dangerous cargo were strengthened. In 2000, my late wife and I visited Halifax and saw some of the markers commemorating the explosion, a rather sobering experience.