Saturday, October 18, 2014

Engineering the River Highway

We would be remiss to not devote an entire blog to discussing the primary human use of the Illinois River: commerce. Us paddlers are not the main characters in this post; it’s the barges we saw, the locks and dams we passed through, and the Army Corps of Engineers that is behind it all. Now, for the story of the Illinois River highway.

Engineering the River Highway

Not surprisingly, commerce currently dominates the river traffic on the Illinois. We saw a decent number of pleasurecraft (aka recreational motorboats), and a small handful of fellow paddlers, but the vast majority of boats on the river were massive, lumbering barges. Made up of a single tugboat pushing a long chain of barges (storage vessels that float), this unit is the standard for river commerce these days. And the river highway has been engineered to make barge travel as easy as possible.

This barge is moving upstream (right). The white tugboat (left) is pushing the linked barges from behind.

Before it was made into a “navigable” river, commerce still took place on the Illinois. For a while, the French voyageurs were the main traders on the waterway, and their canoes functioned as the first barges on the river. Despite the chance that disaster could strike at each set of rapids, they dared to use the river in its natural state. Although we too are paddling the river hundreds of years later, it is nowhere near as dangerous or difficult a task. In fact, we’re paddling a totally different river.

From right to left in the image, barges descend the river like a staircase
Original artwork by Daniel M. Short
To accommodate the larger riverboats that could make shipping more efficient, the Army Corps started to manage the river around the turn of the twentieth century. The river was transformed into a deeper, wider and slower beast, predictable around every turn. To make this happen, the Army Corps built seven lock-and-dam structures on the Illinois to control its flow and depth. The water between an upstream lock and a downstream lock forms into a “pool,” basically a stretch of the river that stays at a fairly uniform height. These pools in effect create a gigantic staircase for boats: each step is level for several miles, then the lock drops the water level up to 35 feet at once, then the river levels out again. Without much elevation change between locks, the water flows slowly – good for barges, sad for canoes.

The dredging boat sucks up sand and water, sends it through a pipe...
To aid commerce further, the Corps dredges the river, removing sediment from the bottom to maintain a channel depth of 9 feet, deep enough for fully loaded barges. With constant maintenance, the Army Corps has tamed the wildness out of the Illinois, standardizing it to meet the specifications of modern barges.

...that deposits it here, alongside someone's corn field. Mark is wondering who will clean up this mess.

The Last Lock and Dam

Barges and locks and dams were so much a part of our everyday experience on the river that we barely noticed them by the end. I wouldn’t be writing about them so long after their mystique wore off if not for our visit to the Melvin Price Lock and Dam on our very last day in Illinois. We were already done with paddling – we’d packed up our canoes and sent them back to Minnesota with Natalie the day before – so we transported ourselves by car/legs down to the lock and dam in Alton.

Melvin Price Lock and Dam - an impressive and formidable structure
Photo credit to George W. Goeken
Melvin Price is actually on the Upper Mississippi, and it is the largest, most state-of-the-art lock in the country. Completed in 1989, it’s also the newest lock, replacing one built in 1938. Many of the nation’s existing locks were built in the early part of the 20th century, so most are severely aging and no longer meet the needs of modern barges. A single tugboat is currently allowed to tow 42 barges at a time, making for a single floating entity that is nearly 1200 feet long. The standard lock chamber is only 600 feet long, which forces tugboats towing full capacity to send only half their barges through the lock chamber at a time. That requires detaching the upstream half of the barge tow, locking it through, mooring that half, returning the lock chamber to its previous water level, then sending the second half through and reconnecting it. A frustrating process, to say the least. We felt the consequences of this inefficiency more than once. One day, we spent over three hours sitting in the rain while we waited for our turn to be locked through. Not fun for us paddlers, but for the barge companies, it equates to a huge amount of potential dollars lost.

Melvin Price from above: small chamber on left, large chamber on right
In one of their greatest construction feats ever, the Army Corps constructed the Melvin Price Lock and Dam to have two lock chambers, one the standard 600 feet and the other 1200 feet in length, the first of its kind. This means that a tugboat can send all its barges through at once, cutting the wait time from 2 or 3 hours to 20 minutes. Given its proximity to the mouth of the Illinois and Missouri Rivers, Melvin Price is one of the most heavily trafficked locks in the country. Earlier this year, they found out how inefficient this specific lock would be if it was the standard size. Some of the cables on the large chamber were corroding, so the Army Corps closed that chamber for maintenance from January to August. With only the 600-foot auxiliary chamber operational, river traffic backed up dramatically. Some barges had to wait 3 to 4 days for their turn to lock through! The effects of this slowdown reverberated through the economy, with price increases in certain sectors.

Most people forget about river commerce, but barges are big business. After we toured the Melvin Price Lock and Dam, I picked up a lot of cool facts and statistics at the on-site Great Rivers Museum to reinforce this claim. As mentioned above, the Army Corps has engineered a river that allows a 24/7 shipment of goods upstream and downstream. In general, coal, steel, chemicals, and oil move upriver, while corn and soybeans move downriver. On the Upper Mississippi alone (the river north of St. Louis), barges transport $77 billion of goods each year! And they do so in a much more economical and fuel-efficient way than trucks and even trains. Barges produce nearly a quarter of the emissions that trucks produce with the same amount of cargo. At this time, barges represent 14% of intercity commerce in the U.S., and they make up only 3% of the total cost. Seems like the government should be pouring a lot of resources into expanding river commerce. But putting more barges on the river isn’t the solution; we would need to rebuild dozens of locks to be the size of Melvin Price to see massive improvements in efficiency. Is it worth the multi-multi-billion dollar investment? Maybe. The Army Corps is currently rebuilding the Olmsted Lock and Dam on the Ohio River, which could be the next step in a major overhaul of America’s river infrastructure. If it does happen, it will likely take a long, long time.

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