When aging infrastructure brings barges to a standstill for as long as 12 hours, all the design in the world can't save what amounts to $100 million in delay-related costs.

As the crew gets the 12 grain barges properly positioned and lashed together in Pig's Eye Lake on the southern side of St. Paul, Minn., Captain Gene Rider tells us the crew is returning to the tow boat after having been on vacation for 30 days. They drove in last night and this morning after a 12-hour drive from Paducah and St. Louis. Several crew members grabbed a much-needed afternoon nap before setting sail this evening on the 670-mile trip to St. Louis that may take anywhere from 9 to 12 days.

Pig's Eye Lake is the marshalling area for assembling the barges for the Upper Mississippi River tows. Barges are filled upstream with grain from the huge Minneapolis grain elevators that are accessible only by truck or train. The barges are then brought down one or two at a time through two sets of locks at St. Anthony Falls

Rider says last fall's late corn and soybean harvest had a dramatic impact on barge traffic. During the last month of the 2009 upper Mississippi River shipping season, he estimates the number of barges hauling grain to New Orleans dropped by 90% compared with previous years. The major season for moving grain south on the river is from September to early December.

Later during our trip, we'll pass tow boats on the river heading north without any barges. They're heading to St. Paul to move empty barges down river for the winter shipping season.

Captain Rider says that's practically unheard of and very costly.

He says the 195-foot long by 35-foot wide barges at first glance look all the same. But the barges have different front designs — called squares and rakes – and must be positioned properly in the tow for efficient and safe movement on the river.

Square fronted barges are placed in the center area of a three-wide tow. Barges with rakes have rounded front corners on the bottom and are placed at the outside of the tow to more effectively deal with the ever-changing river current and high waves. The three out-front barges would normally have a square front barge lashed between two rake front barges.

Today, more than 90 million tons of all types of materials move each year on four types of barges on the Upper Mississippi River:

• Grain, fertilizer, cement and other materials move in covered dry cargo barges that offer protection from the weather.
• Open hopper barges transport bulky materials such as sand, gravel or coal.
• Liquid cargo tank barges handle petroleum, liquid fertilizer oil and molasses.
• Flat deck barges handle equipment, materials or products that can be tied down and don't require any protection from the weather.

For our tow, a dozen barges are lashed three abreast and stretch out 780 feet in front of the tow boat. When we add three more barges 2 days later downstream at LaCrosse, Wis., the captain will have 975 feet of barges stretching out in front of the wheelhouse.

As we get underway, Captain Rider explains that there are 27 locks between Minneapolis and St. Louis for the crew to navigate with this tow. There can be no more than 15 barges in an Upper Mississippi River tow. But since there are no locks between St. Louis and New Orleans, 25 or 30 grain barges are often lashed together in a tow in that part of the river.

Captain Rider says most of the 27 locks drop 12 to 14 feet. "But the lock at Burlington, Iowa, drops 53 feet," he says. "From Minneapolis to New Orleans, there's a 1,400-foot drop. Between Minneapolis and St. Louis, the river drops 350 feet."

He says that because most of the locks are 600-feet long, that means we have to break the tow in half to get through a lock, float half the barges through the gates and then bring the remaining barges and tow boat through the lock.

"Going south," he says, "the river current will float the first set of barges out of the locks. Heading north, the first set of barges are winched out of the locks."

And as we'll soon see, it takes several hours to get through the locks, not counting any delays. During the busy summer months, a tow may wait 6 to 12 hours when pleasure boats, fishing boats and numerous barge tows are waiting at the locks. These waits are expensive as the typical tow boat burns 80 gallons of diesel fuel per hour.

With 1,200-foot locks, it's a simple three-step process. We'll illustrate an example as we're moving south on the river.

After the tow enters the lock, the water level is dropped anywhere from 12- to 53-feet and then the dozen or so barges and tow boat exit the lock. This can be accomplished in 45 minutes.

But this turns into a nine-step nightmare at the outdated two dozen or so locks that are only 600 feet in length. Once the tow enters the lock, the lashed-together tow has to be manually broken apart by the crew. The tow boat and remaining barges are then backed out of the lock. The first set of barges is lowered as the water level in the lock is dropped and the river's current is used to float the barges south through the lock, which are then secured to the southern breakwall.

Next, the lock's water level is raised and the remaining barges and tow boat move into the lock. Then the water level is lowered before the remaining barges and tow boat tow can move out of the gates. Finally, the crew cables the dozen barges back together before the tow can move down river as a single unit. This normally takes 2 or 3 hours.

Building 1,200-foot long locks would eliminate many costly delays. In fact, an Illinois Farm Bureau analysis indicates delays at the locks cost Midwestern farmers $500 an hour in lost crop value. Since the cost to operate a tow boat is about $9,000 per day, lock delays are estimated at $100 million a year.

With 1,200 foot rather than 600-foot locks, 15-barge tows could breeze through the longer locks in 45 minutes compared with a typical 3 hours when splitting the barges. It takes 30 minutes to split the barges in half and twice as long to reattach the cables to the tow.

While it normally takes 20 days to go from Minneapolis to New Orleans, this time could be sliced in half with 1,200-foot locks.

Rider says only three of the 27 locks on the Upper Mississippi River are 1,200 feet long, which means this tow must be broken in half for 88% of its lock passages. That means the crew will spend over 3 days of their time on this trip simply getting through the more than two dozen locks!

So if we're going to move twice as much grain to market 20 or 30 years from now when 300-bushel corn and 100-bushel soybean yields represent the U.S. average, then we'll need to spend hundreds of millions of dollars to update the river's ancient system of locks that are operated by the U.S. Corps of Engineers.

In the next segment of Shipping Out, Part 4, we'll show you how why the Mississippi River transportation system has earned a D-minus grade.