McDonald Quarry

An 1887 accident in Alexander McDonald’s limestone quarry is a reminder that operating safely means doing things the right way every time. This approach is why Nova Scotia’s mining and quarrying industry has reduced its injury rate by 90% in recent decades.

McDonald’s quarry, in Brentwood, Colchester County, employed about 40 men and provided limestone to the Londonderry Iron Works, where steel was first produced in Canada in the 1870s. Limestone is used as flux in the smelting process to promote fluidity and remove impurities in the form of slag. Many of Nova Scotia’s limestone quarries provided the mineral for this purpose.

On December 22, 1887, McDonald and his men were preparing to do a large blast the following morning. Blasting is done in most mines and quarries to free rock from the rock face so it can be gathered and processed.

They expected cold weather overnight, so they decided to take the dynamite to their boarding house and thaw it there.

The key ingredient in dynamite is nitroglycerin, an explosive liquid. It is very powerful but extremely unstable. 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 it, but careless thawing methods caused many historical accidents.

At McDonald’s quarry, the dynamite was usually thawed by a fire in the pump house, but they needed a lot of it the next morning, and the cold weather would make thawing it in the pump house a slow process.

So, they instead decided to thaw a kettle full of dynamite cartridges at the house.

According to the Halifax Herald’s December 24 edition, the cook at the house, Mary Harris, disapproved but “McDonald laughed away her fears saying: ‘Life is as sweet to me as to you, Mary.’ He little dreamed of the sudden approach of an awful death from the very force of which he then talked so lightly.”

The newspaper described how the men decided to thaw the dynamite: “This morning at five o’clock the kettle was placed upon the fire. Every precaution was taken to prevent accident. The dynamite usually freezes at a minimum degree of cold, and the process adopted at the quarry on this occasion was to put a kettle filled with the explosive into a larger pot which contains water, place the same upon the fire, and thaw gradually somewhat in the same way as glue is melted. Mary Harris again cautioned McDonald, but he smiled and said that everything was safe. The cook then proceed to get breakfast for the men. The night shift was late coming out to breakfast, so she put their breakfast into the oven, gave Mr. McDonald and four other men theirs, poured out the tea, and then retired to the cook room or kitchen to drink a cup of tea herself.”

At 6:35 a.m. “the explosion occurred, and McDonald and three others were hurried into eternity in an instant of time, burying their mangled bodies beneath the debris of the building which was now flat with the ground, and torn into splinters,” reported the Herald. “The men in the quarry heard the terrific blast, and knew in an instant that the dynamite had exploded. They were aware of the terrible consequences which might attend such an accident and rushed with blanched faces out of the rock cutting, up the hill to the ruins. People lived all round the neighborhood, but they were used to blasts in the quarry and many of them were not informed of the accident until the doctors arrived to care for the wounded.”

Alexander McDonald was killed instantly. The Herald described him as “wealthy, but a hard working and unassuming man. He leaves a wife and six children.”

Three others were also killed: “Finlay McDearmid was married, his age was 28.” Edward Wesell and James Hoffman were single.

Mary Harris was found unconscious, but largely uninjured other than a cut on her head. She was likely saved by her decision to have her tea in the kitchen on her own. She was taken to a neighbour’s house to recover.

Harry Hinds was found under a mattress, ten yards from the flattened house. He was “bleeding from a dozen wounds, but alive and conscious.”

The explosion could have been much worse. A case of dynamite was found on what had been the stairs, but the dynamite was still frozen solid and did not explode.

Had McDonald followed the usual practice of thawing the dynamite in the pump house, the explosion would not likely have occurred.

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.

McDonald's quarry is shown near the centre of this section from a 1903 Geological Survey of Canada map.

The McDonald Quarry provided limestone to the Londonderry Iron Mines.