|
|
Tales of |
| Your location: Rideau Region > Rideau Waterway Home > Tales > A Rock for Dinner |
 of the RIDEAU  Tales' HomeOliver's FerryWatson's MillGhosts of KilmarnockGrand Non-OpeningLost Barrel of SilverOpinicon GhostsLady in BlueChristmas 1826A Rapid RideBlue Edged BowlsWashed AwayThe Last DuelDavidson's GhostA Rock for DinnerSluiced SuperintendentThe Failed GatesA Grave RevealingBye ByThe Lake Lock |
by Ken W. Watson It was February, 1831, a beautiful winter day at Kingston Mills. The contractor in charge of building the locks and dams at this location, Robert Drummond, was sitting down for his noon meal at his house, located 180 metres ( 600 feet) from the upper lock. His foremen had joined him, and, as usual, they were discussing the business of the day as they enjoyed a hearty meal.
In the upper lock pit, crews were busy laying a black powder charge. The only way to excavate the pit in the hard bedrock at Kingston Mills was to blast it. A hole was laboriously drilled using sledge hammers and hand drilling steel. Black powder was poured in and tamped down. A fuse was laid and the hole tightly sealed with clay. A man, standing behind cover, blew hard on a horn, warning all around that a charge was about to be set off. A single man stood in the lock pit, his hand holding a red glowing torch. Only one man was allowed the light the fuse, everyone else was away from the pit, hiding behind cover. As the final sounds of the horn echoed back from the hills, the man by the charge applied his torch to the end of the fuse. As the fuse started to smoke the man ran for dear life. One never knew exactly how long it would take the fuse to set off the charge, and learning from hard experience, whoever lit the fuse had to be nimble on his feet. A man of experience, our fuse lighter reached a safe place in good time. Whomph – the charge went off. In the meantime, as the fuse burned, Drummond and his men continued to enjoy their lunch. They were aware that blasting was taking place in the pit, charges were set off with no fixed schedule, whenever a charge was laid, it was immediately set off. So, the sound of the warning horn, followed a few minutes later by the sound of the explosion didn’t faze them a bit. But, right on the heels of the explosion, came a huge crash as a 315 kg (700 lb) rock ripped through the side of the house, narrowly missing the diners. Chairs were scattered as the men, somewhat dazed, unsure of exactly what had happened, scrambled to their feet and ran from the house to find out what was going on. The rock has passed right through the walls and now lay a few dozen feet away, on the other side of the house. Drummond quickly took stock of the situation, seeing with relief that no one had been hurt. There was no point in berating the men who had laid the charge, blasting rock with black powder was an unpredictable affair. A few months before, a rock weighing about 9 kg (20 lbs) had gone through the roof of his house. These things happened. In fact, as the surge of adrenaline drained away, Drummond was more interested in finding out how a rock of that size and weight had been able to travel the 200 yards from the upper lock pit to his house. During the building of the Rideau Canal, rock was excavated either by hand (pry-bars) or the use of explosives. At the time of construction (1826-1832), the explosive in use was black powder (also known as gunpowder). Dynamite wasn’t to be invented (by Alfred Nobel) until 1866. Black powder is made up of a mixture of saltpeter (potassium nitrate), brimstone (sulphur), and charcoal. It is a “deflagrating” explosive, that is, it is a slow explosive when compared to today’s high explosives and blasting agents. When a black powder charge goes off, it takes some time to burn (in explosive terms) and heaves the rock, rather than shattering it. Black powder was very dangerous to use for a number of reasons. The explosive force of the blast was difficult to determine. It depends on the amount of powder, the grain size of the powder, and the pressure under which the blast is initiated. A hole would be drilled using hand steel, the powder poured in, a fuse laid and the hole sealed. The idea was to confine the blast (pressure) in order to increase the force of the explosion. Today we can calculate the effect of a blast, but at the time of the building of the Rideau Canal, it was by guess and by gosh. So, when a blast went off, no one really knew how much rock would be blown up, or how far that rock would travel.
Another problem with black powder is that it can be set off by a spark. Today’s explosives and blasting agents require a high explosive charge to set them off (i.e. a blasting cap) and most can actually be burned quite safely (they just burn, they don’t explode). Not so with black powder. An errant spark can set off a charge, so one has to be very careful with the transport of black powder and the setting of a charge. A final problem lies with the setting off of a charge of black powder. The fuses of the day were made using black powder, often a tarred hemp cover surrounding a line of powder. The grain size of the powder, the thickness of the powder in the fuse and the pressure it was under all affected the burn rate. The bottom line is that the burn rate was unpredictable. The earliest version of a “safety fuse” wasn’t invented until 1831. As an example of the danger of black powder is the fact that at least five of the twenty-two Royal Sappers and Miners that died during the building of the Rideau Canal, died of directly as a result blasting accidents; two dying from “quarry blasts”, two from “blasting accidents” and one from “explosion” [Stanzell, p.200]. These were men trained in the safe handling of black powder. But even with this training, black powder accidents happened. Lt. Colonel John By himself was no stranger to black powder. In 1812, he was appointed Commanding Royal Engineer of the Royal Gunpowder Mills in England. This occurred shortly after an explosion, in November 1811, killed eight men and seriously wounded one more at the Waltham Abbey gunpowder works. By ended up designing some new presses for the mills and instituted several safety measures for the added protection of the mill workers. But even with By’s knowledge of black power, blasting rock with gunpowder during the building of the Rideau Canal was a risky exercise. John MacTaggart noted a problem encountered early on in construction with some of the immigrant Irish volunteering to work in the quarry (because of the higher wages), despite their lack of experience: “Some of these, for instance, would take jobs of quarrying from contractors, because they thought there were good wages for this work, never thinking that they did not understand the business. Of course, many of them were blasted to pieces by their own shots, others killed by stones falling on them. I have seen heads, arms, and legs, blown about in all directions ; and it is vain for overseers to warn them of their danger, for they will pay no attention. I once saw a poor man blow a red stick, and hold it deliberately to the priming of a large shot he had just charged. I cried out, but it was of no use. He seemed to turn round his face, as if to avoid the smoke; off went the blast, and took away his arm, and the half of his head : he was killed in a moment. As the blocks of stone fell, one of them broke the leg of another poor man, who knew nothing of such a shot being fired. At length we got the matter so systematized, that a number of shots were always prepared to be fired at once; a person stood at a distance, and kept blowing a horn, so that all the quarriers got out of the quarry to a respectable distance before the mine was sprung.As we’ve seen with the Sappers and Miners, it was a dangerous job even those experienced with the handling of black powder. We do have to put MacTaggart's story into some context - he was writing a book that he hoped would be saleable and was describing some of the more lurid examples of problems, this account should not be taken as the norm. Dr. Christie reported seven deaths by accident between May and December 1827, and the Montreal Herald stated in its December 15, 1827 edition, in reporting the deaths of two labourers from a cave-in, that "Two have be before this killed by blasts … and one killed by a tree falling on him." [Price p.132] In terms of the rock flying through Drummond's house at Kingston Mills, it was just a fluke of circumstance. The rock was likely fractured, and the rock broke on these lines of fracture, propelled by the force of the charge towards Drummond’s house. It was nothing that the people of the time could have predicted, and, if the documented history is correct, it didn’t happen again. One can imagine though, that, in the weeks following this incident, Robert Drummond tensed a little bit every time a new charge was set off. 
Sources: Andrews, Mark, "For King and Country, Lieutenant Colonel John By, R.E., Indefatigable Civil-Military Engineer", Heritage Merrickville Foundation, Merrickville, 1998. Bush, Edward F., "The Builders of the Rideau Canal, 1826-32", Manuscript Report 185, Parks Canada, Ottawa, 1981 Canadian Industries Limited, "Blaster’s Handbook", Sixth Edition, CIL, Explosives Division, Montreal, 1968 MacTaggart, John, "Three Years In Canada", two volumes, London, 1829. Patterson, William J., "Lilacs and Limestone, An Illustrated History of Pittsburgh Township, 1787-1987", Pittsburgh Historical Society, 1989 Plousos, Suzanne, Working with Tools, Work, Identity and Perception Communicated through the Material Culture of Work in the Context of the Rideau Canal Construction, 1826-1832, MA Thesis, College of William and Mary in Virginia, 1996. Price, Karen, "Construction History of the Rideau Canal," Manuscript Report 193, Parks Canada, Ottawa, 1976. Stanzell, John “Royal Sappers and Miners: Builders of the Rideau Canal 1826-1831” Ontario Genealogical Society, Ottawa Branch News, V.40, No.4, pp 199-200, August-October 2007 Tatley, Richard, "Kingston Mills, A Brief Resume", Manuscript Report Series 413, Parks Canada, 1977
|
Comments: send me email: Ken Watson
