Locking Through

Locking Through. . , From 1885 to 1929, fifty-one dams were built across the Ohio River. The dams maintained a minimum 9 foot channel depth. To get around a dam, boats passed through a lock. , 1. When a boat goes up the river, the upstream gates (A) ane closed and the drain valve (B) is opened This allows the lock chamber to cmpty by gravity. The downstream gates (C) open and allow the bout to enter the chamber , 2. The drain valve and downstream gates are closed. Water enters through the opened fill valve (D) until it is level with water beyond the upstream gates. , 3. The upstream gates open and the boat leaves the lock chamber to continue up the river. This procedure is reversed if the bot is going river. , Stories , Ralph Lindsey recalled that one boat crew always passed him a bag of coffee as they locked through. , In 1964, a barge moving too fast into the lock knocked the roller gates of their track. Since the Meldahl Dam was nearly completed repairs were never made Chilo Lock and Dam was closed forever. , Air Tanks , The Chilo lock was controlled from the powerhouse. Large air tanks on the third floor provided the pressure to open and close the gates. , Roller Gates , The Chilo lock used roller gates instead of miter gates. The gates were made out of wood and laid on iron wheels. They were pulled on their tracks by wire ropes wound on drums. , The advantage of roller gates was that they allowed more room for boats to pass. Their disadvantage was that sediment easily accumulated around the gate's wheels, causing them to jam or derail. Many roller gates were replaced with miter gates. Chilo, however, kept its roller gates throughout its operation.