Wikipedia:WikiProject Military history/News/December 2017/Op-ed


 * By TomStar81

On December 6, 1917, an explosion occurred in Halifax, Nova Scotia, that would rock the world and establish a very unwanted milestone for the community. The incident, which had its root in World War I, would set a record that by some criteria remains unmatched to this day.

The groundwork for the incident in question was laid a few years earlier when the United Kingdom, operating on a war footing in Europe, began importing material for use on the front lines – specifically for the Western Front. These incoming shipments arrived in the British Isles by way of cargo freighters, but the Imperial German Navy had loosed submarines into the Atlantic Ocean to intercept and stop the shipments. The Royal Navy, caught off guard by the efficiency of the submarines, labored tirelessly over the next few years to overcome this handicap, with telling results. By 1917 the Royal Navy had gone from being largely at the mercy of the Imperial German Navy's submarine campaign to being arguably the world's foremost authority on anti-submarine warfare (ASW), much to the anguish of the German Navy, which now suffered under the effective anti-submarine tactics. With control of the Atlantic and its shipping lanes now tipped back in Britain's favor, surface assets and wartime convoys were beginning to pour into the British Isles en masse and largely unmolested. Combined with the U.S. entry into World War I and and sudden influx of fresh recruits to the Allied trench lines, and the equally important overthrow of the Russian Empire and the rise of a socialist state in the east, and the German Empire was understandably concerned about the progress of the war and its ability to stand largely alone on the Western Front. Even accounting for the recently signed armistice between Russia and the Central Powers, which would allow for Germany to redeploy its Russian front assets to face the incoming British, French, and U.S. forces, the German Empire was still uncertain about whether or not it it could beat back the Allies on the Western Front.

It was against this backdrop that the tramp steamer SS Mont-Blanc, a classic three-island style, general cargo steamship, arrived in New York fully laden with TNT, picric acid, benzole, and guncotton. Mont Blanc had been purchased by Société Générale de Transport Maritime (SGTM), a French company that had taken ownership of the freighter for the purpose of moving wartime supplies to Europe. Under the command of Aimé Le Medec, she was to sail north toward to join a convoy forming up in Halifax for the Atlantic crossing. Francis Mackey, a harbor pilot, had come aboard the vessel on December 5 to pilot the freighter into Halifax. He had inquired about special protections (like a guard ship) for the journey, which was understandable given the freighter's cargo, but was told that the ship would have no such protections for the journey, meaning the safety and security of the vessel, her cargo, and the crew would come down to his piloting capability.

Meanwhile, in Halifax, the White Star Line cargo vessel SS Imo had arrived on December 3 for neutral inspection ahead of her intended destination of New York. Although operated by the South Pacific Whaling Co, she was under charter from the Commission for Relief in Belgium to pick up a cargo of relief supplies in New York. The vessel had cleared inspection and was authorized to depart from Halifax on December 5, but was in need of re-coaling beforehand, and therefore stayed in the harbor until December 6 to take aboard the coal for the trip to New York.

On the morning of December 6, 1917, Captain Haakon From transferred command of Imo to Pilot William Hayes, and the vessel got under way around 7:30 AM. Authorized to leave Bedford Basin by the guard ship HMCS Acadia, Imo began her trip to New York. Around the same time, Mont Blanc got under way under for the Bedford Basin under the command Pilot Francis Mackey. Navigating into or out of Bedford Basin required passage through a strait called the Narrows. Ships were expected to keep to the starboard (right) side of the channel as they passed oncoming traffic; in other words, vessels were required to pass port to port. Ships were restricted to a speed of 5 kn within the harbor, but Imo had been late leaving due to the need to load coal and as a result was speeding in an attempt to make up the time lost to coal reload, which was against the rules in place. Already over the speed limit for the passage, Imo encountered the U.S. tramp steamer SS Clara traveling up the wrong side of the passage; after signalling, both ships agreed to pass to starboard as opposed to the required port to port passing. Although both ships had avoided a collision by agreeing to pass to the starboard, this maneuver put Imo into the path of the tugboat Stella Maris, which was sailing roughly in the middle of the channel. To avoid striking Stella Maris, Imo had to veer further off course, which now put the 5,043-ton maritime vessel in the path of the explosive-laden Mont Blanc.

Mackey sighted Imo a distance of about 0.75 miles from Mont Blanc, and using his signal whistle notified Imo that his ship had the right of way, but Imo replied with a blast indicating she would not yield her position. To offset the growing danger Mont Blanc's captain had the engines cut and tweaked the course slightly to starboard, signalling the course change in hopes that Imo would likewise follow, however Imo again replied to the negative. As the risk for collision began to grow astronomically, Mackey ordered Mont Blanc hard to port in an effort to avoid striking Imo. For but a moment the maneuver appeared to work; both ships had cut engines and speed was such that it may have been possible for the vessels to simply bypass each other, but at the last moment Imo sounded three blasts from the signal horn to indicate that she was reversing engines. This caused Imo's head to hit Mont Blanc at around 8:45 AM. While the damage to Mont Blanc was not severe, it toppled barrels that broke open and flooded the deck with benzol that quickly flowed into the hold. It may have been theoretically possible for the incident to have ended there as a mere collision, but Imos reversed engines ultimately sealed Mont Blancs fate: as the whaling ship pulled out of Mont Blanc the metal on metal action caused sparks to fly across the cargo hull. This in turn ignited the benzol that had leaked across the cargo hull.

Mackey and the crew aboard Mont Blanc attempted to contain the fire, but there was never any real chance of a crew so small getting ahead of and extinguishing the benzol-fueled blaze. The attempt to contain the fire quickly evolved into an attempt to get as far away from the vessel as possible. As the crew made for shore aboard lifeboats they discovered that many citizens had emerged to watch the impending collision and were now observing the fire raging on Mont Blanc. Acutely aware of the danger in having so many people in close proximity to a burning cargo of high explosives, the crew shouted warnings to the crews on other ships about the nature of the cargo, but they could not be heard above the noise and confusion. Now crewless and thus at the mercy of the current and tides, Mont Blanc continued to drift and eventually beached herself at Pier 6 near the foot of Richmond street. Meanwhile, the tugboat Stella Maris was alerted to the fire and doubled back to Mont Blanc after jettisoning her barges. The crew quickly realized that the fire was beyond their ability to contain with just one hose. In an attempt to limit casualties, the captain backed off to obtain a line with which he hoped he would be able to get Mont Blanc off the pier and out of the developed area, however it was not to be.

At 09:04:35 the raging fire finally succeeded in heating the explosive cargo to critical mass, resulting in a cataclysmic explosion that annihilated Mont Blanc and eradicated most of Halifax. The blast created a shock wave that radiated away from the explosion at more than 1000 m per second, while temperatures of 5000 C and pressures of thousands of atmospheres accompanied the moment of detonation at the centre of the explosion. On top of this, the now white-hot metal fragments and other remnants of what had moments earlier been a steamship rained down across the area, touching off fires and further damaging the already devastated community. In the harbor itself tons of water, suddenly super-heated, dissipated near instantaneously to briefly reveal the harbor floor before the rushing water flooded in to fill the void, which resulted in a tsunami. The cataclysmic blast also generated huge smoke cloud visible for many miles, while the blast itself could be felt over 100 miles away in Cape Brenton and Prince Edward island. In the immediate aftermath of the blast some 1,600 had been killed and over 9,000 wounded.

Almost immediately the surviving crews and uninjured civilians initiated rescue and recovery efforts, which were aided in part by Vince Coleman. Accounts of his actions are conjecture, but it is known that this telegraph officer had returned to his post to stop an incoming passenger train and it is thought that he remained as his post to telegraph other stations along the way to halt trains heading for Halifax. His messages are thought to have helped organize a railroad relief group which brought badly needed supplies into the area. As has undoubted happened in every major disaster throughout history, anyone able-bodied came out to help in whatever way the could. While the rescue and relief efforts began almost instantaneously, an equally important but more malevolent matter also began in the immediate aftermath: the blame game.

Initially, it was assumed that some sort of German attack had taken place in the harbor to have caused such an explosion. Royal Navy, U.S. Navy, and U.S. Coast Guard vessels in the vicinity of the explosion had been badly rocked by the blast – in the case of Tacoma the crew actually went to general quarters before spotting the massive smoke cloud and altering course to assist the Halifax survivors. German citizens were quickly rounded up and detained, while Imo's helmsman, John Johansen, was arrested after reports of him behaving suspiciously were made and a note written in what was thought to be German were found on his person (the letter would turn out to be written in Norwegian). As word spread of the true cause of the blast fears of a German attack dissipated, although rumors and yellow journalism continued to point the finger of blame at Germany. Initially judicial inquires concluded that Mont Blanc was entirely to blame, but this was fueled in part by strong anti-French sentiment, and eventually appeals and other judicial processes would establish that both Imo and Mont Blanc were equally responsible for the disaster. Despite the massive loss of life and the sizable destruction brought on as a result, no-one from either ship was ever tried or convicted for the loss of life and property.

The legacy of the Halifax Explosion survives today in both the monuments to the victims and the blast itself, which is listed among the largest artificial non-nuclear explosions in history. It has been said that the explosion remains unchallenged in overall magnitude as long as five criteria are considered together: number of casualties, force of blast, radius of devastation, quantity of explosive material, and total value of property destroyed (Jay White, 1994). Between approximately 1917–18 and 1945, the Halifax explosion was the explosion by which all others were judged. Halifax lost its status officially after the Trinity explosion ushered in the age of atomic ordnance, but it would be another month before the public display of uranium and plutonium weaponry at Hiroshima and Nagasaki would cause the public to make the switch to nuclear weaponry as the basis for measuring other massive explosions.