Description : PANAMA CANAL LOCKS . The Panama Canal locks is a lock system that lifts a ship up 25.9 m (85 ft) to the main elevation of the Panama Canal and down again. It has a total of six steps (three up, three down for a ship's passage). The total length of the lock structures, including the approach walls, is over 3 kilometres (nearly two miles). They are one of the greatest engineering works ever to be undertaken at the time, when they opened in 1914. No other concrete construction of comparable size was undertaken until the Hoover Dam in the 1930s.There are two independent lanes of transition (each lock is built double, so there is a two-lane traffic system). The locks physically limit the maximum size of ships which can transit the canal; this size became known as Panamax.The locks are to be expanded in the near future to allow more and larger ships to use the canal.