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230:, and over four hundred barges, were stranded when the lock was shut down. A large, rock-filled steel cell—used to help align barges prior to transiting the lock—split causing the channel to be blocked with rock. The cause of the incident was attributed to exceptionally low water levels. The steel cell has armored sections, to protect it from impacts and abrasion from the heavy barges. But the water had fallen so low that barges were impacting an unarmored portion of the shaft.
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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
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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
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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
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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.
186:, and the lock is located over 3 miles (4.8 km) southeast on the Chain of Rocks canal. The canal and locks allow river traffic to bypass a portion of the river that is unnavigable in low water due to an
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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
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Upper
Mississippi River 9-Foot Channel Project, Lock & Dam 27, Granite City, Madison County, IL
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This low water dam across the
Mississippi maintains a minimum pool level upstream of the locks.
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An accident caused the lock to be shut down on
September 15, 2012. Over four dozen
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and they are the only Locks south of the confluence of the
Mississippi River and
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The Chain of Rocks Lock is operated by the St. Louis
District of the
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Transportation buildings and structures in
Madison County, Illinois
315:"Missouri: Damaged Lock Snarls Barge Traffic on Mississippi River"
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The Chain of Rocks Canal and Locks in
Madison County, Illinois
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Chain of Rocks Lock and Dam - U.S. Army Corps of Engineers
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List of locks and dams of the Upper Mississippi River
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344:"Barge Traffic Halted near Mississippi River Lock"
210:. Locks No. 27 are the southernmost locks on the
24:Chain of Rocks Lock and Dam (Lock and Dam No. 27)
718:Historic American Engineering Record in Missouri
713:Historic American Engineering Record in Illinois
182:. Its associated dam is just downstream of the
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743:Transport infrastructure completed in 1953
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388:Historic American Engineering Record
323:. September 19, 2012. p. 21.
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194:in the river—a "chain of rocks".
342:Suhr, Jim (September 19, 2012).
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163:situated at the southern end of
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18:Dam in Madison County, Illinois
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708:Dams on the Mississippi River
656:(Melvin Price Locks and Dam)
208:U.S. Army Corps of Engineers
129:U.S. Army Corps of Engineers
733:Mississippi Valley Division
367:in decades, officials said.
283:Annual tonnage through lock
153:Chain of Rocks Lock and Dam
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686:no further locks and dams
678:Melvin Price Locks and Dam
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524:Lower Saint Anthony Falls
519:Upper Saint Anthony Falls
295:New Chain of Rocks Bridge
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390:(HAER) No. IL-33, "
728:Mississippi River locks
463:Winnibigoshish Lake Dam
453:Ottertail Power Co. Dam
222:September 2012 shutdown
145:Upper Mississippi River
662:(Chain of Rocks Lock)
473:Blandin Paper Co. Dam
356:on September 20, 2012
184:Chain of Rocks Bridge
96:38.70311°N 90.18094°W
271:Chain of Rocks locks
131:, St. Louis District
443:Stepping Stones Dam
101:38.70311; -90.18094
92: /
320:The New York Times
723:Locks of Illinois
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212:Mississippi River
180:Mississippi River
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136:Dam and spillways
112:Opening date
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738:Rock-filled dams
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352:. Archived from
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52:United States
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41:Official name
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478:Potlatch Dam
468:Pokegama Dam
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358:. Retrieved
354:the original
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190:exposure of
157:Locks No. 27
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44:Locks No. 27
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684:Downstream:
493:Sartell Dam
458:Knutson Dam
448:Vekin's Dam
120:Operator(s)
99: /
75:Coordinates
702:Categories
301:References
188:anticlinal
87:90°10′51″W
84:38°42′11″N
675:Upstream:
169:St. Louis
349:ABC News
330:passage.
325:Archived
289:See also
228:towboats
173:Missouri
141:Impounds
69:Illinois
57:Location
234:Gallery
192:bedrock
175:on the
159:, is a
49:Country
177:Upper
167:near
436:Dams
362:2012
200:weir
161:lock
115:1953
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Text is available under the Creative Commons Attribution-ShareAlike License. Additional terms may apply.
