The Rideau Canal

A Marvel in British Engineering

Ottawa, Ontario Canada

July 22nd, 2001

On one of our many walks through Ottawa, Capital of Canada, we stopped along the Rideau Bridge to watch the Rideau Canal locks being worked by hand. For those with a mechanical mind or just an interest in classical engineering feats that allow man to simply overpower the forces of nature, bending it to his own will, this can be a fascinating place. A little understanding of the setting is in order. The war of 1812 is over, but Canada stills fears the wrath of the new power emerging in the US. The St. Lawrence River in the narrows west of Montreal, is now perceived as vulnerable to American attack and protection of the upper lakes area could be threatened. A point on the Ottawa River in the east and Kingston in the west appeared to be at either end of the perceived choke point on the St. Lawrence. England, decides to create a secondary water rout around the St. Lawrence, sufficiently inland to afford protection. Lieutenant Colonel John By, was sent to carve the Rideau Canal out of the rugged north. It was intended as a safe passageway for British gunboats that might be facing possible American bombardments along the St. Lawrence River, the canal instead became one of the city's most successful commercial ventures. Pulp and paper mills soon rose and log booms jammed the Ottawa River, creating a prosperous lumbering village eventually called Ottawa, after the Outaouac Indians. By's job was to connect a long running string of lakes and rivers with man made canals, and then produce locks at each end sufficient to raise and lower boats the 162 feet needed to reach the high point at Upper Rideau Lake. Col. By, arriving in 1826, with a compliment of Royal Engineers plus thousands of Irish immigrants, French Canadians, and Scottish stonemasons, began to push the canal through the rough brush swamps and rocky wilderness of Eastern Ontario. Completed in 1832 with over 11 miles of connecting canals dug, the Rideau Canal was one of the greatest engineering feats of the 19th century. For me, the intriguing part of all this was the locks. Equipped with nothing more than what they could build with simple hand tools, Col. By and his engineers constructed dozens of locks. Designed to handle a boat 90 feet long with a width of 26 feet, the locks were operated by hand cranks turned by either one or two people. Although each lock is different, they could displace around 10 feet of water. The route was never used in war, but quickly became the supply route for logging operations in central Ontario. Bytown, as it was called at the eastern entrance of the canal, soon became Ottawa, and the rest is history. More than 175 years later, the canal is a live and vibrant means of transportation for the many pleasure boats that travel the water way. The old wooden door locks with their original chain pulling hand cranks the only means of opening and closing all but two of the locks. As we joined the crowd that is always present on the Rideau Bridge overlooking the canal locks, I listened to an old timer who was telling his grandkids how the locks worked. As he explained, the water only flows one way, from the bridge down through the locks into the Ottawa River. To move a boat either way, two locks must work together. The locks always have water in them. When a boat wants to go up river, it sails up the Ottawa river to the first lock which opens it doors and allows the boat to enter the lock. the rear door to the Ottawa river is then closed. Through an underground water valve, the water of the lock right above the one with the boat in it, is allowed to run into the lower lock. Within a few minutes the water lever of the two locks are equal with the lower lock water level coming up about half the distance of the water level of the upper lock before the valve was opened. when the water level is even there is no pressure on the doors between the two locks and a simple hand crank can pull them apart. Interesting, the combined width of the doors is slightly larger than the width of the canal, causing the doors to close in a shallow V. It is this shape that allows the doors to remain closed with thousands of pounds of pressure being exerted against them when the water level between two locks is unequal. With the water level equal and the doors pulled open the boat sails into the upper lock and the rear door is closed. The process is repeated until the boat reaches the top of the hill and the canal water is level with the top lock level. The last door is opened and the ship sails on. To move a boat downstream, one other step is required. Starting at the bottom, the water valve in each lock must be opened and the water lowered to make room for the water from the canal when the boat first enters the locks. After that it is just a matter of equalizing the water between two locks and walking the boat down the hill. Neat don't ya think? The canal itself has a maintained depth of around 5 feet so most small power boats can travel the length of it without problems. Canada's Parliament is built on a hill just to the west of the locks so there is all kinds of things to see while waiting for the water to change. The entire canal is part of the Canada Parks System as such the locks are operated by young strapping and sometimes shapely guys and gals working summer jobs. All in all quite entertaining for a hour or so.

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