Detail of a canal lock door. Lock gates can weight up to 700 tons, the weight of 300 elephants. The Panama Canal locks lift a ship up 85 feet 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 doors are made entirely with rivets because welding was not a developed technology. These are the original doors that started service in 1914.