Peterborough's Lift Lock

We are traveling to former IBM co-worker and friend, Pat's, cottage north and east of Toronto - we're excited to get to participate in "cottage country"!

For tonight, we have stopped at a Walmart in Peterborough, ON. Pat recommended that we visit the Lift Lock so we unhooked the Jeep and made a drive across town to see this engineering feat that is over 100 years old!

Richard Birdsall Rogers, who designed and supervised the construction of the lift lock, was born and raised in Ashburnham near the site of the lift lock. 

In 1884, he was appointed superintendent of the Trent Canal by the federal government. He convinced the Minister of Railways and Canals to undertake this bold project - building an enormous lift lock rather than a flight of locks at Peterborough. He prepared the plans and supervised construction of the structure.

He was also responsible for introducing a technical innovation to Canada - the use of concrete rather than traditional stonework in canal construction.

 A schematic of how it works... (copied from an information board)
 1. The chambers (A and B) are mounted on rams (C and D), each of which plunges into a water-filled cylinder (E and F). The cylinders are connected by a pipe (G). A valve (H) in the middle controls the flow of water between the cylinders.
2. The boats enter the chambers. In our example, the boats going downstream enter chamber A and the boats going upstream enter chamber B. During this operation, valve H is closed.
3. Chamber A is heavier than chamber B. This is because extra water has been added to it by stopping it 30 centimetres lower during the previous manoeuvre. When valve H is opened, the water under pressure in cylinder E is pushed toward cylinder F through pipe G. Ram D and chamber B rise.
4. Once chamber B is up, valve H is closed and an extra 30 centimetres of water is let in to prepare for the next manoeuvre. Then the gates are opened.
5. The accumulator (I) is a column of water with a ballast on top connected to the main hydraulic circuit. Since some water is always lost during a manoeuvre, the rising chamber may need an extra push to reach the desired height. The accumulator provides this push.

Building the lift lock involved mixing and pouring almost 20,000 cubic metres of high quality, unreinforced concrete. It was the biggest single pour of concrete in the world at the time.

Concrete is made of cement, gravel, and water.... Some 175,000 barrels of cement went into the lift lock. It was mixed to exacting specifications in a steam driven mechanical mixer and moved to the various parts of the construction site by crane and hopper. There it was poured into forms in layers 25 centimetres thick (about one foot) and allowed to cure. You can see this layering effect in the towers of the lift lock if you look closely.

 ...

The Peterborough lift lock has been working reliably since 1904. Another lift lock, built at Kirkfield, has been operating since 1907. To ensure that these locks continue to serve the public effectively they were renovated between 1963 and 1966 and some original components were replaced with modern equipment. On the whole, the basic structure and operation of the locks has remained unchanged. Famous for their advanced technology eighty years ago, they have now gained a reputation for enduring workmanship.

" The hissing, chuffing and thumping of steam machines was heard throughout the construction of the lift lock. Utility steam boilers, steam powered water pumps, locomotives and steam shovels were some of the machines that fascinated the citizens of Peterborough. This was the first time that steam had been used in construction in Peterborough."

Unfortunately, we arrived too late in the day to see the lock in use - it seems at this time of year, it is only commonly used for a tour boat that goes once on weekdays. But the ranger said that it was quite busy during the summer months when many boaters use the Trent-Severn Canal to travel between Lake Ontario and Lake Huron. The ranger told us that it is used by boaters doing a grand North American Great Loop from Florida, up the Mississippi, through the Great Lakes, and then ultimately down the inland waterway on the east coast. http://www.greatloop.org/content.aspx?page_id=22&club_id=574480&module_id=192093

It was a beautiful day to take in this site!