The Panama Canal is a ship canal that extends across the Isthmus of Panama, joining the Atlantic and Pacific Oceans. It runs generally southeastward from what was known as Cristobal on the Caribbean Sea (an arm of the Atlantic) to Balboa on the Pacific Ocean. The canal cuts across the lowest point in the continental divide and through one of the narrowest points between the two oceans.
An impressive engineering feat, it was built 1904 - 1914 at an initial cost of $366,650,000. Although it is only half the length of the Suez Canal, it took the same amount of time and more than three times the cost to build. Unlike the Suez, which is at sea level for its entire length, the Panama Canal has locks to raise and lower ships. Dams hold back two artificial lakes, Gatun and Madden, that supply water for the locks.
The canal was built by the Isthmian Canal Company, after attempts by the French failed, under the provisions of the Spooner Act and was opened in 1914. It is 50 miles long from deep water in the Caribbean to deep water in the Pacific. Although there are 12 sets of locks total, there are only six massive pairs of locks that ships use for transit, each 1,000 feet long and 110 feet wide. Each may be filled or emptied in less than 10 minutes, and each pair of lock gates takes two minutes to open. A 30,000-pound fender chain at the end of each lock prevents ships from ramming the gates before they open. Water is not pumped into and out of the locks, but flows from the artificial lakes through culverts 18 feet in diameter. Electric towing locomotives, called "mules", pull ships by cable through the locks. Most ships require six of these mules, three on each sides. (New Standard Encyclopedia, 1976)