Canal Walk

On the morning of the 27th of September, the Bucknell in London group took a mile and a half walk along Regent's Canal. Here, we learned the mechanisms and workings of the canal locks as well as the function and importance of the canal itself. There were many exciting parts of the trip, including getting to open and close the canal locks ourselves as well as Jeremy, Paul, Chris, Chizz, Kyle and Wes pulling out a drowned motorbike from the depths of the water.

In conjunction with the science aspect of our common course, one of the main objectives of the tour of the canal was to learn about the operation of the locks. A lock is a device that is situated in different sections of a canal and controls the water level to enable the raising and lowering of boats that pass through the canal. All locks are composed of three basic elements. The first is the watertight chamber, a body of water which connects the upper and lower canals and is large enough to enclose one or more boats. The position of the chamber is fixed, but its water level can vary. The second is a gate, which is located at either end of the chamber. A gate is opened to allow a boat to enter or leave the chamber, and when closed, the gate is watertight. The last element is a set of lock gear to empty or fill the chamber as required by the boats. As we saw at Regent's Canal, this is usually a simple valve, traditionally a flat panel (paddle), lifted by manually winding a rack and pinion mechanism which allows water to drain into or out of the chamber.

If a boat is traveling upstream, the process is as follows: the first lock gate opens and the boat enters the chamber. The gate closes behind the boat. The valve on the opposite side of where the boat entered is then opened to allow water to flow into the chamber, which in turn causes the boat to rise as the chamber fills to the level of the water on the other side of the lock. (The water level on the other side of the lock is maintained by pumping and water flowing from the upper reaches of the canal.) The second lock gate opens when water levels between the outside of the canal and the inside of the lock are equal. (The gate opens against the flow of water which means that the gate can only be opened when the levels are equal.) The boat then leaves the lock through the second gate, and the valve and the lock gate are closed behind it.

In a fundamentally similar yet different comparison, if a boat is traveling downstream, the process is as follows: the first lock gate opens and the boat enters the chamber. The gate closes behind the boat. The valve built into the lock gate on the opposite side opens allowing the water to flow out of the chamber. The boat is lowered as the water level in the chamber falls. The second lock gate opens against the flow of water and so the gate can only be opened when the levels are equal. The boat then leaves the chamber and the valve and the lock gate are closed. As one can see, the process of the functioning of the lock is similar between upstream and downstream travel with the exception that when traveling upstream, the valve must be opened to fill the chamber with water, but when traveling downstream, the valve must be opened to allow water to escape from the chamber.

Locks within a canal are necessary for very important reasons. As canals were being constructed in more "ambitious" (unlevel) areas, locks became necessary to offset the changes in water level caused by uneven ground. Locks eliminated the need for detours, which would have been completely uneconomic in both construction costs and journey time. Essentially, locks are used to make a canal more easily navigable and also to allow canals to take a reasonably direct line across terrain that is not level.

The other main objective of our tour of Regent's Canal dealt with the other aspect of our common course, economics. This canal has served many purposes, the main of which was commercial traffic. In the eighteenth and early nineteenth centuries, cars, trucks, railways and trains were very seldom if even available. With this, canals served as the main way to import and export goods. This greatly supported London's (as well as Britain's) economy as goods were constantly being shipped out as well as shipped in, which helped to regulate commerce and employ many workers. While this activity has greatly declined, the canal still supports London's economy through water-based tourism, leisure activities, and informal recreation.

Even though it was rather chilly, I still had a great time touring Regent's Canal. Getting to open and close the locks was my absolute favorite part. It was also fun to see the old tavern sign dating back to the 1800s, and watch the boys pull the motorbike out of the canal.