Canada's Capital - Set in Stone*
A tale of two bridges?
THE TALE of the construction of the Union Bridge is far too enthralling to cut it short, and it's best read, coming from the pens of the two men who were witnesses to it all.
That being said, when the story is read, the accounts of John Mactaggart [1] and Thomas Burrowes [2] agreed on what was built, but not necessarily on how it was built ... or rather, by whom it was built.
Thomas Burrowes gives all the gory details of how the first arch collapsed, confessing it had been built in too much of a hurry. He lets us in on how the urging of Philemon Wright & Sons was what finally moved Mactaggart to order Burrowes & John Burrows [3] to draw up new plans for a better dry-stone* arch, which was then successfully built by Philemon Wright & Sons.
*Built with no mortar
Mactaggart's serving of the tale has a different flavour. Remembering that John Mactaggart is ultimately the one who made the decisions, his account of the failure of the first arch is ... umm ... let's just say ... slim. This is all that he writes:
"A temporary bridge had been thrown over the same place before, which had fallen."
In his full Report on the Chaudière Bridge, Mactaggart writes that he was the risk-taker and ultimately the problem-solver; and it was he who planned and completed the dry-stone arch over the first 17.5 metre-wide channel.
The two accounts give us a good snapshot of the pitfalls of 'engineering' in the early 19th century and how the confidence of the engineer was perhaps more in play than were, necessarily, the concepts of engineering.
As both the Union Bridge and the Rideau Canal progressed, there would be several other failures before both projects were completed, giving us other examples of how much engineering in that day was perhaps as much trial and error as it was something gained from true experience.
Getting a handle on the Big Kettle
DURING the Summer of 1827, the second stone arch and the two cantilever bridges were completed. The smaller truss bridge over the Rafting Channel had also been completed in September 1826, at the same time the first stone arch was being built.
Then came time to tackle the 64-metre wide channel at the Big Kettle Falls - not a task for the faint of heart. The difficulty, as Mactaggart described it, was not just the width of the channel but also the depth of the water; "a sounding-line hath not yet found a bottom at 300 feet deep", he wrote.
To bridge the chasm, however, it would be neither Mactaggart nor Burrowes who would provide the solution to get past the first hurdle. Full credit must go to Heraldus Estabrook, Captain of the Hull Militia [4], who fetched one of the two three-pound cannons from the Hull Artillery shed, brought it down to the the edge of the Big Kettle's channel and fired a rope across.
For the first trial a half-inch rope was used, but the force of the explosion cut it. They tried again but with the same result. At the suggestion of one of the workmen, a one-inch rope was then used and fired right over the island. Four thicker ropes were then attached to this, and were drawn across to form a swing or rope bridge.
Of the rest of the operation, Thomas Burrowes would write:
"A timber Trestle ten feet high was erected on each side of the channel, ropes were stretched over their tops, forming Catenary curves, and were made fast to the rocks at each end. On these ropes planks were laid transversely at proper distances, having holes bored in them and pins projecting through to keep the ropes at the proper distances from each other. On these planks boards were laid longitudinally, and near the ends cleats were nailed to the boards to facilitate walking without slipping. This Bridge was erected by Mr. Drummond [5] in one-half day, and was of great assistance in facilitating the work."
"The Chains - three in number - were next stretched across. Those used were thought to be too weak, but no others were available. The timber for this bridge was prepared on the large island, and the string pieces were put together on rough piles of logs which raised them to the required height to give the proper curve to the Bridge. A few days proved the inefficiency of the chains to support the strain, for one of them gave way and precipitated several men into the River, who were rescued by the promptness of their comrades; a boat being always kept on hand in case of accidents. To lessen the strain on the chains as much as possible, Lieut.-Col. By adopted the method shown in the annexed sketch, and the work proceeded with rapidity."
The sketch (above) shows that two scows were anchored to a point of rock and had jack-screws placed on their decks to help support the weight of the bridge. Burrowes' narrative continues:
"Such was the confident anticipation of a successful termination of the work that Mr. Drummond, in the early part of November, undertook a contract to complete it for £430. During the winter nothing material occurred to retard progress, but great care was requisite to guard against fluctuations of the River acting on the Scows and consequently the Bridge. Notwithstanding all the precautions used, the chains were found to be too weak. On the 10th of April, 1828; when the work was nearly completed, the chain on the lower side of the Bridge gave way, precipitating eight men into the water, one of whom was unfortunately drowned*. At the moment this chain broke, one of the carpenters had his hand saw under is arm, and although precipitated a height of about 40 feet into the raging torrent below, and having to swim for his life, when he was picked up by the men stationed in the boat, it was found that he had never quitted his hold of the saw!"
*While accounts vary, as many as three men drowned.
Eventually, all of the work completed gave way and crashed into the river. Knowing it was the weak chains that caused the accident, Col. By secured some 'Patent-studded' chains from His Majesty's Dockyard in Kingston and ordered the reconstruction of the bridge with a greater width. The superior chains held and the bridge was successfully completed in the month of September, 1828.
Commencing the Canal
COL. BY had spent the winter of 1826-27 in Montreal, planning for the commencement of the canal construction, which would be the next summer.
The Rideau Canal project would begin with confirming the route and entrance of the Rideau Canal, Mactaggart's task to be completed over the winter, and the construction of the infrastructure that would permit an enormous project of this nature to begin: The barracks, the steamship docks, the storehouse for goods and supplies and the lodging for the workers. It would be a busy winter for both Col. By and for John Mactaggart.
*The date, event and people in this account are real. The personalities, their reflections and their characteristics are based wholly on the personal accounts written by John Mactaggart (Three Years in Canada, Vol I and II), the written account by Thomas Burrowes (Observations) , and the personal letters of the Philemon Wright and family (The Wright Papers, LAC).
FOR PART IV, click here.
[1] John Mactaggart was an engineer and author who was hired by Lieut.-Col. John By as the first Clerk of the Works for the Rideau Canal project. (click here for more info)
[2] From the account entitled Observations by Thomas Burrowes, surveyor, engineer, and artist. Burrowes arrived in Canada with his family in 1826, and secured a position as Overseer of Works on the Rideau Canal construction project. Here he came under the wing of John Burrows, a fellow Overseer of Works, who claimed that he trained Thomas Burrowes in the skills of surveying, and prepared him for his registration as a Provincial Surveyor. Later promoted to Clerk of Works of the southern section of the Rideau Canal, Burrowes continued in this service until 1846. Excerpts of his writings were taken from Ottawa Past and Present by A.H.D. Ross. (click here for more info)
[3] John Burrows (Honey) surveyor, engineer, artist, and politician; eventually replaced Mactaggart as Clerk of the Works of the Rideau Canal. (click here for more info)
[4] The colonial militias were generally the local sedentary militia regiments of non-professional soldiers throughout the Canadas, prior to Confederation. Heraldus Estabrooke was one of the many settlers of Wright's Town listed in the roles of the Hull Militia. The first Captain of the Hull Militia, commissioned in 1808, was Philemon Wright.
[5] Robert Drummond made his name as one the main contractors on the Rideau Canal. He was responsible for the construction of a dam and four locks at Kingston Mills, a lock and dam at Davis Mills, and a lock, dam, and waste-weir at Brewers Mills. (click here for more information)
