Chain of Rocks Lock
Chain of Rocks Lock and Dam (Lock and Dam No. 27) | |
---|---|
U.S. Army Corps of Engineers, St. Louis District | |
Dam and spillways | |
Impounds | Upper Mississippi River |
Chain of Rocks Lock and Dam, also known as Locks No. 27, is a
The 8.4-mile (13.5 km) canal, 1,200-foot (370 m) main lock, and 600-foot (180 m) auxiliary lock were built in the late 1940s and early 1950s to allow a by-pass of the Chain of Rocks lying in the main channel of the Mississippi River. This stretch of river in low water seasons was treacherous for commercial tow boats and barges, often requiring them to wait several days for the river to rise. The dam for lock 27 is atypical for the Mississippi, being a weir made of tons of rock laid in the Mississippi to create a small pool elevation upstream from the Chain of Rocks. The drop at Locks 27 can vary from a few feet to over a ten-foot drop depending on the river stage.
The Chain of Rocks Lock is operated by the St. Louis District of the
September 2012 shutdown
An accident caused the lock to be shut down on September 15, 2012.[1] Over four dozen
Gallery
-
The Chain of Rocks Canal and Locks in Madison County, Illinois
-
This low water dam across the Mississippi maintains a minimum pool level upstream of the locks.
-
Chain of Rocks locks
-
Annual tonnage through lock
See also
References
- ^ "Missouri: Damaged Lock Snarls Barge Traffic on Mississippi River". The New York Times. September 19, 2012. p. 21. Archived from the original on January 8, 2017.
Workers closed Lock 27 just north of St. Louis after discovering that a protection cell—a vertical, rock-filled steel cylinder against which barges rub to help align them for proper entry into the lock—had split open, spilling tons of rock into the channel and obstructing passage.
- ^ Suhr, Jim (September 19, 2012). "Barge Traffic Halted near Mississippi River Lock". ABC News. Archived from the original on September 20, 2012. Retrieved September 20, 2012.
That damage was on an unarmored section of the protection cell that the barges don't typically make contact with because that portion often is 15 to 20 feet under water. But that part of the structure stands exposed because the river's level has been lowered dramatically by the nation's worst drought in decades, officials said.