Panama Canal Locks
Overview
 
The Panama Canal Locks, which lift ships up 25.9 m (85 ft) to the main elevation of the Panama Canal
Panama Canal
The Panama Canal is a ship canal in Panama that joins the Atlantic Ocean and the Pacific Ocean and is a key conduit for international maritime trade. Built from 1904 to 1914, the canal has seen annual traffic rise from about 1,000 ships early on to 14,702 vessels measuring a total of 309.6...

, were one of the greatest engineering
Engineering
Engineering is the discipline, art, skill and profession of acquiring and applying scientific, mathematical, economic, social, and practical knowledge, in order to design and build structures, machines, devices, systems, materials and processes that safely realize improvements to the lives of...

 works ever to be undertaken at the time, eclipsed only by other parts of the canal project. No other concrete construction of comparable size was undertaken until the Hoover Dam
Hoover Dam
Hoover Dam, once known as Boulder Dam, is a concrete arch-gravity dam in the Black Canyon of the Colorado River, on the border between the US states of Arizona and Nevada. It was constructed between 1931 and 1936 during the Great Depression and was dedicated on September 30, 1935, by President...

 in the 1930s. The total length of the lock structures, including the approach walls, is over 3 kilometres (nearly two miles).

The locks, which have a total of six steps, limit the maximum size of ships which can transit the canal, known as Panamax
Panamax
Panamax and New Panamax are popular terms for the size limits for ships traveling through the Panama Canal. Formally, the limits and requirements are published by the Panama Canal Authority titled "Vessel Requirements"...

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