Dynamite

In 1879, a gold miner in Tangier died as a result of “thawing dynamite improperly,” according to the Department of Mines’ annual report.

Before dynamite was invented in 1867, black powder explosives (sulfur, charcoal and saltpeter) were used to break rock. However, they were not very powerful, and they were dangerous to transport. Nitroglycerin, an explosive liquid, was invented in 1846 by Italian chemist Ascanio Sobrero by treating glycerol with a mixture of nitric and sulphuric acid. Nitroglycerine allowed for more powerful explosions but it was extremely unstable and even less safe than black powder.

In 1867, Alfred Nobel stabilized nitroglycerin by adding diatomaceous earth to make dynamite. It was safer than black powder and much more powerful. Dynamite came to be widely used in mining and construction, and it expedited the building of roads, railways, tunnels, canals and other construction projects worldwide in the second half of the 1800s.

Nobel’s goal was to make explosives safe for workmen, but he was troubled by dynamite’s potential to be used for destructive purposes. He became one of the world’s wealthiest people as a result of inventing dynamite and when he died in 1896, he left his estate as an endowment for annual awards in chemistry, physics, medicine or physiology, literature, and peace – the Nobel prizes.

Freezing dynamite made the nitroglycerine more stable and safer, so it was, for example, often shipped packed in ice. Dynamite’s freezing temperature is only 11 degrees Celsius, so freezing it was not difficult. However, its low freezing temperature also meant that dynamite could become frozen unintentionally in cooler weather, especially in the simple buildings and shacks in which historical miners often stored it. Dynamite had to be thawed before using, but careless thawing methods caused many historical accidents.

On Tuesday, December 9, 1879, about 10:00 a.m., blacksmith Joseph Ferguson was heating a gad (a chisel or pointed iron or steel bar for loosening rock) at the forge in the western shaft house on Tangier’s Fields Lead (a gold-bearing quartz vein). His cousin, Jim Ferguson, was inserting a capped fuse into a dynamite cartridge. George Ferguson, Sr. was also in the building, as were Joe Mason and a fisherman whose last name was Logan.

A tin food can was being used to thaw three cartridges of dynamite in hot water. The tin can was sitting on the forge, not far from the fire.

John Fraser Torrance, a mining engineer from Montreal who did some work in Nova Scotia, was just a few yards from the shaft house when, as he described it, “Suddenly the explosion occurred. Jim and Joe Ferguson were hurled in a heap into one corner of the house, and Old George also fell in inside. Joe Mason and Logan declare that they themselves were blown bodily through the doorway of the building on to the dump. The shaft house was considerably injured by the explosion, but by no means wrecked. And nobody was injured by falling timbers; in fact none fell.”

Jim Ferguson was seriously injured by the blast. According to Torrance, “The dying man lingered apparently unconscious for about half an hour after he was carried home. His wounds were chiefly in the lower part of the body, and his hands were but slightly injured, which proves to my mind most positively that the detonator and cartridge in his hands never exploded.” Even though Jim had been inserting a fuse into dynamite at the time of the explosion, that cartridge was not the one that exploded.

Torrance believed “The probable cause of the accident was the overheating of the can, and its consequent dryness. Such an accident would be practically impossible with one of the patent warming cans for dynamite. Several other cartridges had been removed from the can less than five minutes before the explosion, otherwise all five men would probably have been instantly annihilated. As it was, it is providential that none of them were blown down the open [mine] shaft, at the bottom of which their comrades were working. The Coroner's inquest was held that afternoon, and a verdict was returned, simply to the effect that the deceased came to his death by the accidental explosion of dynamite.”

While dynamite is still used today, the most commonly used explosive in Nova Scotia’s mining industry is ANFO (ammonium nitrate and fuel oil). ANFO is as powerful as dynamite but much safer.

Today, the storage and use of explosives at mines and quarries is stringently regulated by the federal and provincial governments to ensure safety. For example, explosives must be stored in a magazine separate from operational areas and any combustible materials. Detonators and explosives must be stored separately, and magazines must be kept locked and closely monitored.

Historical accidents are a key reason why the modern mining industry is so safety-focussed. Nova Scotia’s mining and quarrying industry has reduced its injury rate by 90% since the Westray inquiry report was released in 1997. We believe the most important thing to come out of a mine is the miner, and our modern safety record reflects this.