Wednesday, October 3, 2001
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Wednesday, October 3, 2001 |
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Freight barges along, slowly but surely By
SALLIE SATTERTHWAITE
The recent collision of a barge and a bridge on the Texas coast would have been front page news in other times. But given the events of Sept.11, the wreck was relegated to a few small paragraphs on the inside. A section of the Queen Isabella Causeway the only link between the mainland and South Padre Island, a popular resort island dropped into 50 feet of water, taking several vehicles with it, and at least five lives. Accidents like this are rare, and early indications are that it was caused by malfunctioning navigation lights on the bridge's piers. The barge master said the lights were not on when he fetched up against a sand bar that sent his tow drift into the pier. Odds are that landlubbers like us seldom give a thought to the monster vessels plying America's 25,000 miles of navigable rivers and canals, 12,000 of them maintained by the federal government as commercial waterways. They deliver enormous quantities of grain, coal, petroleum and other products around the clock to and from storage depots and manufacturers wherever there's a dependable channel. Waterways are among the few investments the federal government makes that return more benefits to the public for more than 50 years. For each dollar spent, the U.S. Treasury gets about six dollars back. Consider: A single barge carries the equivalent of 15 train cars plus 58 large semis. On most rivers, a tow (as shipping people call a collection of barges pushed by a tow boat) averages about 15 barges. Such a tow is equal to 2.25 100-car train units, or 225 hopper cars, plus 870 large semis. On average, a truck carries one ton of goods 59 miles on a gallon of fuel, while a ton goes 202 miles per gallon by rail. But an inland barge can haul the same payload 514 miles on one gallon. As you might expect, pollution released into the air is correspondingly reduced. That is, the 15-barge tow emits about a tenth as much as the single semi in tonnage of payload per gallon. I didn't set out to dazzle you with numbers, but I admit to being intrigued by these mighty workhorses of the waterways. Especially close up. We took a road trip through Kentucky and Tennessee this summer while it was still too hot for boating. On our way home, approaching Kentucky Lake Lock and Dam from the west side, we stopped for lunch on a pull-out on the dam. From there, across a panorama of sparkling lake rimmed in green, we could see strings of barges, made fast to mooring cells, waiting to get into the lock. One was already secured to cleats on the long guide wall, as its captain waited for the tow ahead of him to clear the downstream exit. This lock is one of the busiest on U.S. rivers, part of the massive intersection of a riverine interstate system. Here shipping passes between the Cumberland and Tennessee rivers and the highly industrialized Ohio from the east where the Ohio receives the Wabash, the Monongahela and the Allegheny; and the Mississippi connecting with the Missouri and points west, in addition to ports south. We finished lunch, looked at the water for a few minutes, then continued to the turn-off to the lock. I was curious to see what was on board the tow waiting to pass through, so I walked up the ramp to the observation deck to take a look. Dave, no fool, had found a shaded parking place and opted to wait in the camper. When I got to where I could see down into the lock, I realized that this was an opportunity I'd been waiting for. Since nothing was happening at this moment, I ran back to tell my long-suffering spouse that we were going to be here for awhile. I was going to see for myself how a string of barges as big as this gets through a lock only half its length. Here are the logistics: The lock chamber is 110 feet wide and 600 feet long. Its depth, of course, varies according to whether it is at the level of the upper lake or the lower lake, but for the record, Kentucky Lake lock contains about 19 million gallons when filled. The tow in front of me consisted of 15 barges, and was configured three across and five behind each other. A single barge is 35 feet wide and 200 feet long. That means the lock can accommodate only three rafts of three barges, totaling about 600 feet in length. The remaining barges, plus the 65-foot long pusher, would need most of the chamber's length to make it through afterward. So we were about to see the solution of a puzzle we'd long pondered while waiting our turn through a lock in our little trawler while the tow ahead of us seemed to take forever to make its transit: How does the tow master push through part of his load, release it, then reunite with it, with no power or control over the severed barges ahead of him?
Next week: How it's done. . |
