Images of Lock and Dam 24, Mississippi River Mile 243.4, Clarksville, MO

“The Mississippi is well worth reading about.

It is not a commonplace river, but on the contrary is in all ways remarkable.”

Mark Twain,

Life on the Mississippi, 1863

Lock and Dam 24 is located at Mississippi River Mile 273.4, 93.5 miles upstream of St. Louis, at Clarksville, Missouri. Construction of Lock and Dam started in July 1936, and the lock was put into operation on May 12, 1940. It was the first dam on the Upper Mississippi River that was without roller gates, but instead applying Tainter gate technology. Normal pool elevation behind the dam is 449 feet. The movable portion of the dam is 1,340 feet long and consists of 15 fully submersible 25 feet high by 80 feet long Tainter gates. A 2,720 feet submersible earthen dike extends from the movable dam to the Illinois shore. Its 13,000-acre pool is 27.8 miles long. Lock dimensions are the standard 110 by 600 feet, with the upper gate bay section of an auxiliary lock. Average lift is 15 feet.

In 2004, the facility was listed in the National Register of Historic Places as Lock and Dam No. 24 Historic District, #04000183.

Lock and Dam 24 is founded on durable shale, unlike Locks 25 and Old Locks 26, which are pile-founded structures built atop sand and gravel. Because of the presence of a firm foundation material, the lock chamber is not floored and no lateral struts were provided to stabilize the intermediate and river walls.

The Tainter gates are raised and lowered by individual electric motors, connected by line shafting to link-chain hoists, located beneath the dam service bridge. The piers provide support for the Tainter gates and the steel deck girder service bridge that extends the length of the dam. The submersible, elliptical Tainter gates of Dam 24 represent the apex of gate design achieved