The Peterborough Lift Locks
September 5, 2023
H.R. Oakman aerial postcard of the Peterborough Lift Locks
By Guy Scott
The Trent Canal is a local marvel that runs 245 miles from Georgian Bay to Lake Ontario. For much of its length, it follows the Trent/Otonabee River from Balsam Lake to Trenton. The highest point on the whole system is Balsam Lake which stands 263 feet above Georgian Bay on Lake Huron and 597 feet higher than Lake Ontario at Trenton. This means the river is broken by many waterfalls and rapids. To make the system navigable, 43 locks (2 of which have 2 flights—hence they are numbered as 45 locks) were needed. Two of these locks (Kirkfield and Peterborough) were so high, lift locks were necessary.
By the 1890s, construction on sections of the Trent Canal had progressed to the point where the Government of Canada felt it prudent to complete the waterway in its entirety. Two of the highest drops were to be bridged by liftlocks. R.B. Rogers, supervising engineer was despatched to Europe to study three liftlocks; the only ones in use in the world at this time. Rogers was a brilliant engineer who designed both liftlocks on the Trent Cnaal. The one at Peterborough was 65 feet high, making it the largest in the world. Kirkfield came in at 49 feet, the third highest in the world.
The locks use a simple theory of physics to raise and lower large tanks of water. As one basin is raised, the other is lowered. The Peterborough Liftlocks was officially opened on July 9, 1904, and remains one of the engineering marvels of our area. You can actually ‘ride’ the liftlocks in a tour boat: the same as travellers did 108 years ago!