Keeping a Lock on River Traffic

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Photo Courtesy of Dennis Slape.

 

Mother Nature can be fickle and that capriciousness can cause headaches up and down the Illinois River. That’s why a series of eight locks and dams were built along the river in the 1930s, replacing older structures. The dams help the U. S. Army Corps of Engineers maintain a navigable pool at least nine feet deep for river traffic. The locks compensate for changes in river elevation from 420 feet above sea level at the LaGrange Lock and Dam south of Beardstown to 480 feet above sea level at the Marseilles Lock and Dam, a river distance of about 170 miles. The locks and dams were designed for a 50-year life but have now been operating for 75 years.

The 13-man crew that operates one lock and dam 24-hours-a-day must cope with the obsolescent mechanisms that control water levels and make river navigation easier. The current locks, at just 600 feet in length and 110 feet wide, can handle a maximum of nine barges, in a three barge wide by three barge long configuration. That means a typical tow of 15 barges must be split into two “cuts” to go through the lock — nine barges in the first cut followed by six barges plus the tow. 

Once barges have entered the lock chamber and the miter gates are closed, tunnels inside the concrete walls on either side of the lock fill or drain the water, depending on the direction of travel. It takes as long as an hour-and-a-half to lock through today. If Congress approves funding, the lock would be lengthened to 1,200 feet, enabling a “straight single” lock through, which would take as little as 20 minutes.

That would bring meaningful savings to barge operators carrying petroleum, salt, coal, scrap iron and agricultural products. Doug Morgan, the Assistant Lockmaster at the Peoria Lock and Dam, says barges are an economically viable method for transporting these commodities. “The lock and dam system is vital to the American economy, and the Illinois River is one of the veins of our commerce.” The National Waterways Foundation reports that barge transportation is more economical than other forms of transportation, with a 15-barge tow carrying the equivalent of 216 rail cars or 1,050 semi-tractor trailers.

In 1940, when the interconnecting lock and dam system was new, the Illinois, Upper Mississippi and Missouri Rivers saw the movement of 3.5-million tons of cargo. Today, more than 126-million tons of freight annually travel the same rivers. Taxpayers for Common Sense, a group opposed to public funding of locks, points out that even at that amount, the entire inland waterways system carries less than five percent of our country’s freight. Lock and dam construction is financed with taxpayer money and funding from the Inland Waterways Trust Fund through a 20 cent per gallon diesel fuel tax on commercial users. The tax rate has not been raised since 1995 and the fund does not have sufficient money for proposed river construction projects. The Common Sense group points out all maintenance and operation expenses after locks and dams are built are borne by the public.  

The twin to the lock is the dam. At Peoria, the dam is comprised of 108 wickets that are four-feet wide and constructed of iron and oak. The Peoria Lock and Dam works in conjunction with other dams along the river to maintain a navigable pool, which at Peoria is 438.5 feet above sea level. Generally, if the river level falls below that point, the Army Corps will raise the wickets. A hydraulic excavator (yes, it carries Cat colors!) starts on the west side of the river and pulls a hook at the top of each wicket, allowing the wicket to rotate at its base on the riverbed into an upright position. While the wickets are up, a “tainter gate” next to the lock can make slight adjustments in water level. 

With no agreement yet on funding, there is no timetable for when improvements might be made at the Peoria Lock and Dam.