George R. “Al” Goethals is Professor of Psychology and Chair of the Program in Leadership Studies at Williams College. He is the great-grandson of Major General George W. Goethals, chief engineer of the Panama Canal from 1907-1914. In a recent interview with the Williams College Museum of Art, Professor Goethals gave a brief description of the way the Panama Canal works.
The fundamental facts of the Canal operation reflect the fact that it is a lock rather than sea level canal. Theodore Roosevelt and John Stevens made that decision in 1906.
A lock canal was needed to keep the amount of excavation manageable, to make the Chagres River and its terrific floods during the rainy season part of the solution rather than part of the problem, and deal with the fact that the tides on the Pacific side of the canal are about 20 feet while they are only about three feet on the Caribbean side. Three locks on either end of the canal raise ships to a huge manmade lake. Created in turn by a huge dam, the material of which came from the excavation at continental divide at Culebra, the lake is 85 feet above sea level.
The water from the lake comes from the Chagres River, and it is essential for canal operation that Panama protect the rainforest that the Chagres River drains. Otherwise, the water supply will be jeopardized when ships transit the canal and go up or down through the locks.
Water in the lock chambers rises or falls in accordance with the way canal operators open or close valves. Water is simply let into or out of lock chambers, like filling or emptying your bathtub.
Again all the water that goes into the locks comes from the giant manmade Gatun Lake, supplied by the Chagres. When water flows out of the locks, it goes into the oceans.
Each transit consumes about 55 million gallons of water. It is quite thrilling to watch the huge lock gates, weighing hundreds of tons, opening and closing so that the water levels in them can rise or fall, and so that ships can move from one lock or the oceans.
The rudimentary computer system controlling the valves and lock gates is original equipment. A study done several years ago showed that replacing the computers with modern equipment would cost nearly $1 million and improve nothing.
The lock gates are perfectly balanced, despite being about the size of an old VW Beetle engine. They lock like they come from the back of your washing machine. The machinery runs on electricity, which of course is supplied by hydropower from the water from Gatun Lake flowing over the spillway of Gatun Dam.
There are no pumps moving water or generators making electricity. The trick is finding clever ways of using an extremely strong and simple force, gravity.