Locks And Damns

On Friday, March 31st a group of students from all over the United States, along with our professors, took a tour on the Gateway Clipper in order to learn about the system of locks and dams. After departing from Station Square, Mark Devinney lectured to us about the system of locks and dams and their importance.

A lock can be simply defined as "a section of a waterway, such as a canal, closed off with gates, in which vessels in transit are raised or lowered by raising or lowering the water level of that section." A dam works in conjunction with a lock. A dam is "a barrier constructed across a waterway to control the flow or raise the level of water" (Dictionary.com)

Here is my understanding of a how a lock and dam system operates. A lock works where a stretch of water enclosed by gates, one at each end, built into a river for the purpose of raising or lowering a vessel from one water level to another. When the ship is to be raised to a higher level, it enters the lock and a gate is closed behind the vessel. Water is let into the lock until its level equals the water ahead. The forward gate is then opened, and the ship progresses on the higher level. The procedure is reversed when the vessel wants to pass from a higher to a lower level. As many locks as necessary are used in a particular waterway. Sometime a "double lockage" is required. This occurs when a vessel is too large and cannot fit, all at once, through the lock. Therefore, the vessel will be broken down into sections in order to proceed through the lock.

Although all locks work in a similar fashion, their construction can be quite different. As we saw, most locks, today, are made of concrete, although, I discovered through research that some locks have walls made of steel-sheet piles or floors of natural rock or sand (The History Channel). The gates on the locks can also vary. The locks we saw consist of two swinging gates that come together and hold the water and the vessel. There are valves built into the walls of these gates. The valves are the core component of the lock and dam system. These valves are what allow the water to come in and/or out of the gates. The use of valves allows that water levels to increase or decrease, depending on the water levels. As we learned, the gates, on most locks, are operated by hydraulic or electric power.

Although, our group learned a great deal about how a lock actually works. I believe that it was even more interesting to lean of Pittsburgh's lock and dam system. During Mark Devinney lecture, he specifically focused on Emsworth locks and dams. From