How Did This Small Collision Cause The World's Biggest Pre-Nuclear Explosion? 

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The train dispatcher of the Halifax train station, when he heard news of the burning ammunition ship, directed all inbound trains to stop in their tracks immediately, and back away if possible, signing his message off by saying he is not going to make it out alive.

Vince Coleman was an On Duty Train Despatcher for the Canadian Goverment Railways. On finding out a explosition would occur, he remained at his post rather than escaping and chose to warn those along the line that the incoming passenger train would be in harms way. This was his final message : "Hold up the train. Ammunition ship afire in harbour making for Pier 6 and will explode. Guess this will be my last message. Good-bye, boys." R.I.P Vince Coleman, heroic railwayman who should be better remembered for his sacrifice on that fateful day.

My favorite anecdote from the Halifax blast is how one of the Mont Blanc sailors saved a Micmac mother and child. As the crew was heading for safety on the far side of a ridge, there was a woman sitting on her porch with her baby who would be directly hit by the blast. The language barrier prevented the sailor from explaining the unfolding disaster, so, time being of the essence, the sailor grabbed the child and ran. The confused mother ran after the sailor and both were saved.

For a perspective, I've read the Halifax explosion was "equivalent of more than 3,000 tons of TNT, nearly four times higher than the Beirut explosion estimate", and the Beirut one looked absolutely devastating

As a Canadian, I'm fairly familiar with this explosion. However, I think you're the first person I've come across that explained WHY the SS IMO was on the wrong side of the channel.

My dad was in his cradle about two miles from the epicentre. That AM my grandmother had noticed that the rising sun was in his eyes, so she closed the leather hood. When the blast came my aunt was blown down the stairs and all the windows blew out. My aunt was fine, so she ran upstairs to find that the leather hood on dad's cradle had been pierced by dagger like shards of glass. He was fine. Dad lived to be 97 and when he died, he was one of only a handful of survivors still alive. Now go read about the 1945 Bedford magazine explosion, when it almost happened AGAIN! Dad survived that one too out in a lake in a boat as debris rained down all around him.

Used to live there for years. It hits differently to hear this great retelling of the story, knowing the place. Of interesting note, Boston sent relief by train almost immediately. In 1918, Halifax sent a Christmas tree to express their thanks. The tradition was resumed in 1971 and continues to this day. 🎄

When the atomic bombs where dropped the newspapers reported that the blast was equal to 14 Halifax explosions.

The other really unfortunate thing about this explosion was, it was in December in Canada. There was a nasty snowstorm that hit Halifax the next day, and the residents no longer had a roof over their heads. Just an awful situation all around. But one worth remembering.

The SS Imo increased her speed above the harbor limit. The SS Clara was on the wrong side of the passage. The Stella Maris should have been farther starboard as well. The Mont Blanc was the only ship following correct procedure. Yet the Captain of the Mont Blanc was the first to be blamed.

Based on your explanation, I'm surprised that the Imo wasn't found to have the larger portion of the blame... Why does it seem like their mistakes not receive much scrutiny compared to the Mont Blanc who seemed to have been put in an impossible position by factors outside their own control?

I live near Halifax now, and if your from Canada you usually know about it. It's probably the defining moment in the history of this city. Thanks for covering it.

It's worth remembering the Mont Blanc was a French ship with a French speaking crew they tried to warn bystanders when they got to shore, but lacked the words to do so. Some are said to have picked up children and run away from the ship to try to get people to follow them, though I can't confirm this.

Not so fun fact: The SS Imo was formerly called the SS Runic, which once belonged to the White Star Line, the same company which operated the SS Atlantic and RMS Titanic. Atlantic and Titanic both sank near to Halifax and had a substantial amount of their victims' bodies buried there. Coincidentally, White Star Lines biggest rival, Cunard Line, was founded in Halifax. White Star Line always had a part to play in their rival's hometown's worst 3 maritime disasters.

I grew up in Massachusetts so every year we would hear about this story around Christmas time. Boston sent a lot of aid to Halifax after the disaster and every year Halifax supplies Boston with its Christmas tree as thanks.

I live in Canada and the main reason I know of this is because every year as part of our French class we had to choose a topic to do a speech on(increasing in length each year), and every single year this one guy chose this as a topic. Each year he would add a few extra sentences that would pad out the time to meet the new minimum length.

This is the first time I've heard the Imo had already passed two ships on the "wrong" side and didn't have the capacity to turn back. I've always wondered why the didn't want to yield, but this puts things in a totally different perspective for me.

It's one of those things where you have to go to Halifax to really understand how big this explosion was. I remember being there and getting further and further away from the water thinking surely I would have been safe at this distance, but no, I would have most likely died. The Maritime Museum has exhibits on the explosion and one of the largest collections of artifacts from the Titanic since recovered bodies were buried in the city.

Haligonian here! This is easily one of the best summaries of the Explosion I've ever seen on this site. Errors are few and far between, and you present the subject with the candor and grace it deserves. Amazingly well done!

"Not well known"? I guess, if you aren't Canadian... My great-grandmother was quite a ways from the harbour, washing my infant great-uncle in a bassinet near the kitchen door that day, but of course facing the front window wondering what was going on. When the ship exploded, she lost an eye to a shard of the shattered front window. But my great-uncle was unscathed, as the explosion tore the front door off its hinges... landing directly across the bassinet, effectively forming a shield for him. Luckily for my existence, her husband was working on the railroad away from home that day!

“We’re about to cause the biggest non-nuclear explosion!” “What’s a ‘nuclear’?” “No idea! But we’re gonna almost be close to it!!!”

Fire and Flame by The Longest Johns tells the story of the Mont Blanc in the style of a sea shanty, it’s very well done.

The Motherhouse for the Sisters of Charity of Halifax was on the reverse slope of one of the hills. My 8th grade teacher in 1965 told stories of her and other sisters (she was a novice at the time) going through the city after the blast and fire looking for people to help and bodies to recover. It was her 16th birthday. What a way to remember your 16th birthday.

Coincidentally, I was telling my friend from Australia about the Halifax explosion last night. I first learned about it from a Canadian Heritage Minute as a little kid - a series of short history lessons that used to play on TV during commercial breaks. That one focused on the perspective of Vince Coleman, the train dispatcher who stayed behind to telegraph incoming trains, warning them to stop, and thus died in the blast. Nobody had explained the Imo's navigation to me before this though. Thank you.

The maritime equivalent of "I'm a great driver, and I can safely go faster than the speed limit. The authorities just want to control me."

Every year, for the past 51 years, The City of Halifax sends a Christmas tree south to Boston in continual thanks for Beantown's prompt medical and relief aid following the explosion.

Born and raised in Halifax I take the time every year to remember those that lost their lives and the many others that suffered life long disabilities in this tragic event. I can only imagine how difficult it must have been to cope with this at a time when they did not have the luxuries and resources we have today.

In the Marine Museum downtown they have a large exhibit dedicated to the explosion. Seeing solid iron over a foot thick twisted and warped like soft clay sent a chill down my spine.

My great grand mother lived in halifax at the time of the explosion, and she was engaged to one of the fire fighters who responded that morning. He didn't make it, and she eventually married my great grandfather. It's always neat to imagine how big the explosion was when you're going over the Mackay bridge. Nice to see some hometown history on this channel! :)

Crazy how this story is not told more often in transportation safety. An incident of this magnitude reminds me of the explosion in Lebanon a few years back.

Hello from a Nova Scotia native and current resident of a Halifax suburb. I just wanted to say thanks for taking the time to make this video. I always enjoy your work, but this one hits especially close to home. Its surprising how 'unknown' this story is, especially in the younger generation, even in Canada. One of our cross-harbour ferries is named after the railroad telegraph operator who sacrificed his life to try to save the lives onboard an inbound passenger train, and one of the new Royal Canadian Navy tugs under construction is going to be named Stella Maris. The CSS Acadia (the prefix CSS meaning Canadian Survey Ship, a name she earned after WWII when she returned to service with Canadian Hydrographic), her pier-mate HMCS Sackville (the last remaining Flower Class Corvette) and the Maritime Museum of the Atlantic are exceptional museums if you're ever in the area.

One of my moms friends' grandmother was late for school the day of the explosion. She was far enough away that she was fine, but she kept going and when she got to the school her whole class was dead. I don't remember all the details of the story but its awful to think about. And I still remember the heritage minute they played all the time

My Grandmother lived near Charlottetown, Prince Edward Island approximately 180 kilometres (111 miles) from Halifax when this happened. She would have been around 11 or 12 years old at the time and she remembered feeling the ground shaking when the explosion happened. The earthquake caused by the explosion also broke windows in Truro, Nova Scotia approximately 80 kilometres (49 miles) away.

Thanks for covering this! I have always been moved by this tragedy. Interesting fact, the Acadia is actually the CSS Acadia (Canadian Survey Ship) and was the first ship built to survey the Canadian North. She was commissioned by the RCN for both world wars and is the only surviving ship to have served in both.

Wow. The quality of these videos just keeps getting better... you really have a way to tell a story. Such a huge disaster that I'm surprised I hadn't heard more about it. Also, congratulations on the WoWs sponsorship, I always thought it would fit your channel nicely

The toluene onboard was used in F1 cars back in the 80s where was no restriction on the type of fuel. Cars made 1400 HP on it. It was banned eventually. Also was used as rocket fuel.

When I was a college boy, there was a professor from Halifax, Canada and he told us that explosion briefly. It was such a terrible story to hear… 😢

I know all about this and actually searched specifically to see if you did a video about it. But I've live in NS my whole life, growing up in Cape Breton and actually live in Dartmouth now so I learned it all in school. Stoked you did a video about it all! ❤️

Then, the day after the explosion, Halifax was cut off from basically the rest of the world by a blizzard that stopped trains and road traffic. 16 inches (41cm) of snow kept more supplies from coming in for multiple days, and those without shelter were now even more exposed. The snow did help put out some of the lingering fires, so that's a plus, overall a massive disaster largely unknown outside Canada. In the Seattle area we were never taught about it in school directly, but I did learn about it as a tangential piece to a paper I had to write on the impact of submarines in WWI.

one of the reasons why the explosion was so powerful was because when it blew up, the force that would normally be lost travelling down to the sea floor was reflected back by the bowl nature of the harbour, this was actually studied afterwards and is why the Atomic bomb was set as an airbust in 1945; to increase its power. Also the Mont Blanc's captain was initially seen at fault because the entire Mont Blanc crew survived because they abandoned the ship so early rather than trying to fight the fire. Most of the population saw this not only as cowardly but also negligence, as even though they probably could have done very little to stop the blaze they lived while 1600 people did not even though it was THEIR ship. Not a good look no matter the circumstances.

There used to be a commercial series called Heritage Moments that was on Canadian TV and the one for this hits hard.

I randomly stumbled across your channel yesterday and I love it, thanks man.

Excellent video! This event should definitely be more well known.

Thanks for sharing this sad story with us and explaining the details of how it happened. Excellent video, as always.

I've heard this story in detail a hundred times, but I've never SEEN it. Wonderful vid!

There is a great song by The Longest Johns about this tragedy called fire & flame and it goes like this: Let me sing you a song, boys, of fire and flame Of a French ammo ship, the Mont-Blanc was her name How the brave Nova Scotia was never the same On the morning when Halifax burned 'Twas in early December 1917 She was packed to the gills with Grade A T-N-T They were bound for the fighting in High Germany When towards them the other ship turned The Norweigan ship Imo, some fault in her gears She struck Mont-Blanc's side like the mightiest of spears And the benzol ignited the captain's worst fears As the fire consumed bow to stern The people gazed on from their safe distant rooms Watched the soot and the smoke fill the sky with their plumes But within, the ships cargo would spell all their dooms How were they to know to be concerned? The crew rowed for shore, lest they burn or they drown They cried, "Save your souls!" as they ran through the town But their warnings were nothing but strange foreign sounds For the townsfolk, no French had they learned One man, Patrick Coleman, in the railway's employ Sent word, "Stop the trains or they'll all be destroyed This will be my last message, farewell to you, boys" For a true hero's death he had earned An explosion, colossal, when the munitions blew Devastation and debris for miles fired through The Mont-Blanc was gone, and the town with it, too And the waters raged up in return There were heroes and angels all fated to die Over two thousand souls laid to rest by-and-by We will always remember and lift a glass high To the morning when Halifax burned

Simply staggering at so many levels.

Perfect illustration of what happen… I grew up in Halifax and heard the story many times from my father and the few survivors when I was a kid…. I got chills just listening to this… thanks for sharing.

I live in Prince Edward Island, about 250 kilometers from Halifax (it's about a five-hour trip including the ferry off the Island) and was working outside an abandoned home up the road this week. The landowner took me over and showed me one of the windows, which had been cracked in the Explosion. There were windows blown out all across the Maritimes from the shockwave.

I live a couple kilometers from where it happened, we still send a giant Christmas tree to Boston every year as a thank you for their massive support over one hundred years ago

I’m so happy you finally made a video on this, I’ve been waiting since I started watching you ❤

The folk song “Fire and Flame” about this is really good.

I saw several videos on the Halifax explosion, yours is the best.

I am from Halifax. I'm sure many tourists walking through downtown wonder why the north facing city hall clock is wrong. It is stopped at the time of the explosion.

Can’t believe I had never heard of this event, another fine video mate

This is the first time I've ever seen an explanation of why the Imo was on the wrong side.

When the news reached Boston, the Chief Medical Officer there immediately began loading Doctors and nurses onto a Train. he then sent a Telegram to Halifax after the train left stating something along the lines of apologizing for not openly telling them ahead of time and just sending the train

Hmcs Acadia was closed to the public last time I was down to the waterfront a month ago. I think they were doing some conservation work on it. Well worth taking the tour if you ever get the opportunity

A very fascinating and well crafted/narrated video.👏🏼👏🏼👏🏼

I knew about the Halifax explosion, but I had no idea that submarine nets were a thing. Thank you very much for having me learn about this amazing technology. Cheers!

This was a wonderful, extremely detailed, yet concise video! Growing up in Halifax you hear the story and I've read about it in the Maritime Museum of the Atlantic but this gave me the clearest understanding of the order of events that led to the disaster. I'll add, the pilot of the Imo, William Hayes, was a relative of mine and my older relatives didn't like to talk about it as it was still seen as a black mark on the family nearly a century later.

During your WoW ad, there's a bit where it says "Enemy Cruiser Sunk!" In my head, I had the image of USS Johnston coming out of the explosions. :D

Dang, the quality of your animations has definitely improved!

Thank you you are the first you helped me visualize the extent of the damages inflicted to poor Haligonians and the anchor of the Mont Blanc blasted 20 km south of Halifax !!! Wow!

Hey casual navigation! I really really look forward to your videos! Thanks!

Thank you for sharing the history of my hometown!!

Thanks for explaining the initial reason for the collision.

So happy I caught this vid early! The story is insane :O

I learnt about this disaster many years ago as part of my family are from Halifax and Nova Scotia, We visited in the early ninties and I remember seeing the remnant of Mont Blanc's anchor which is now mounted on a plinth were it landed.

Thank you for making this video I’ve been wanting to know more about this

I first learned of this story, from a book I read, when I was six. It stuck with me, since I was young and 🥺, till this day. I remember talking about it, to my Dad. He told me, a kinda realistic version of it, which in turn scared, the crap outta me😱!!! That was 1968, and I still will watch ANY documentary, I come across.

Love the channel. Keep up the awesome work.

congrats on 500k !!

During peace time, ships carrying explosives are required to fly a precise type of flag to warn others. The Mont Blanc being a French ship in 1917, it didn't fly the required flag so as not to paint a crosshair inviting German U-Boots to sink it.

I heard a short version of this story a weirdly high number of times as a kid. Very cool to have some of the blank spaces filled in.

Great video! This was a disaster of unbelievable proportions, a real tragedy.

Thank you for documenting this old incident. In the end, it was a consequence of changed attitudes because of wartime...

I was born and lived in Nova Scotia for most of my life, about 3 hours away from Halifax. Not during the explosion, obviously, but it's history is everywhere in Nova Scotia, especially in museums and information centers. My grandmother was living in Halifax with her husband at the time. I can't remember what he did for work but it was something that had him working around the wharf. When the explosion happened she had no way of knowing if her husband was ok and wasn't allowed to go down to the wharf, plus she had children to tend to. After hours and hours, her husband finally showed up, I can only imagine the relief she felt when he walked through the door.

An interesting related story is the SS Richard Montgomery that sunk after running aground in the UK during WWII. It sits 50ft under water still loaded with 1400 Tons of various bombs. No explosion yet.

When we were there a few years ago we stood by the canon that was thrown miles from the explosion. It is mind blowing to look way off to the distance and think that it came all that way. The maritime museum alone is worth a trip to Halifax. Cheers !

Good Video! Just a few additions to your information. In French, an "I" is pronounced like an "E" in English, so the ship's name is pronounced like EMO. The submarine net extended from McNabb's Island to the Halifax side of the shore of the harbour mouth. When the Mont Blanc arrived at the mouth of Halifax Harbour too late to be admitted, her Captain was so concerned that he had the red hazardous cargo flag taken down. He was nervous that flying the red flag would make the Mont Blanc more of a target while at anchor outside the harbour that night. The Captain was in such a hurry to get inside the safety of the harbour the next morning, that he did not remember to raise the red warning flag. This would have given some warning to other ships that the Mont Blanc was a floating bomb. Your explanation of the reason that the Imo was out of position in the Narrows was the best I have ever seen. Good work.

There's so many side stories like the Christmas Tree , buckets full of eyeballs , Halifax's first fire truck and it's only survivor there's some great books I know who reads books anymore . I myself am from Dartmouth and played on the cannon that was launched when the ship exploded in the late 60's that is.

Love your content, I am always impressed with what you create

Never heard of this before. Thanks for sharing what is a very sad loss of life. Re the Imo, can't believe someone would get that smashed that they collapse and run aground 🤦‍♂️

That was thrilling! And very very sad. Thank you.

The RMS Olympic sailed from Halifax just a couple days before carrying 6000+ troops to the war in Europe. If she'd been delayed by engine trouble or bad weather... Doesn't bare thinking about.

I have heard of it. I remember reading all about it way back in the 70's as a teenager.

You guessed wrong if you think that we haven't heard of it. You underestimated our love of history.

As a Canadian, I have definitely heard of this.

interestingly enough, I first learned about this while interpreting an animation history class. One of the animations they were talking about that day was called “The Flying Sailor”. The instructor shared a fair bit of detail about the incident and what lead up to it, but… Interesting to learn more and have a much clearer idea about the events!

Ever walk down a hall and someone is going in the opposite direction and you both step in the same direction to avoid each other and it produces this awkward dance? Basically that, with ships and tons of explosives.

WOW! I wished I'd known this when I visited Halifax back in 1995! Wonderful history video! Thank You!! ❤❤

Mach wave (also called Mach front, Mach effect, Mach reflection, Mach stem or Mach stem effect), named after Ernst Mach, is the name given to the pressure wave resulting from a bomb exploding above the ground, which is formed by the pressure wave and its reflection on the ground.The air within this pressure wave reaches velocities of several 100 km/s and therefore has enormous destructive power. This effect was deliberately brought about for the first time - under operational conditions - when the atomic bomb was dropped on Hiroshima on August 6, 1945. The bomb exploded at an altitude of about 580 meters. Already on December 6, 1917, this effect was used in the non-nuclear Halifax explosion, when the ship Mont Blanc, lying in the water, exploded and the shock wave was reflected by the water.

Best sponsor pairing yet

I LOVED THIS VIDEO, GREAT JOB.

Never heard of that, interesting video thanks.

Fascinating video. Thanks.

Thank you. I did not know the circumstances of the Halifax explosion.

Really enjoy that subtle red line. 👍🏻