Mississippi River traffic open but I-40 bridge repairs could cause future disruptions

Mississippi River tug and barge traffic, closed after a crack was found on the Interstate-40 bridge linking Tennessee and Arkansas, opened today, according to Deb Calhoun, senior vice president, Waterways Council Inc.

In an email to AJOT Calhoun reported that: “River reopened as of this morning (May 14^th). Queue has 61 boats and 1,058 barges in the queue but that should be cleared by tomorrow sometime.”

However, Calhoun said there are likely to be intermittent closures as the damage to the I-40 bridge is repaired: “There will likely be more limited closures in the next weeks as contractors arrive on site to fix the bridge (from the water).  That is all TBD.”  

Calhoun said the damage to the bridge was caught in time and could have been far worse: “Dodged a big bullet both on the bridge (closed it before catastrophe to cars) and for the waterways (4-day total shutdown that could have been very dicey if it had gone on for much longer – 2 million tons of cargo could have been at a stand-still if it had gone on for a week).”

Adel Abdelnaby, associate professor of engineering at the University of Memphis, challenged assertions by the Tennessee Department of Transportation (TDOT) that the fracture on the bridge may have only been there for a week before being spotted.

In an interview with WMC Channel 5 News, Abdelnaby said he has studied the Hernando-Desoto Bridge and installed sensors to track any abnormalities. 

He says cracks found on the bridge may have been there longer, possibly a few weeks:

“So, this crack is very developed. When I look at the crack, the crack doesn’t look to me like it’s new. The crack looks like the edges of the crack are worn. You see they are round; they are not sharp edges.” 

Abdelnaby studies and teaches bridge fatigue. This happens when tiny cracks in the metal form over time. He explained:

“You are subjecting steel to many cycles of stresses, millions of cycles. Every truck that passes by, that’s one cycle. So, imagine how many cycles have been there since the 1970s.” 

The Hernando-Desoto bridge opened in 1973. Abdelnaby says bridges built during that era were not designed to handle the high volume of traffic that occurs today. Around 41,000 vehicles cross this bridge every day and 30% are commercial trucks.

TDOT says they don’t have a specific timeline for the bridge to reopen.

Abdelnaby says if the damage is confined to just one crack, then repairs could take a couple of weeks. 

If damage to the bridge is more extensive, then the entire Hernando-Desoto Bridge might have to be replaced, he says.

Calhoun told AJOT that 2 million tons of Mississippi River tug/barge cargo could have been at a standstill if the bridge was shut down for a week.

In that case, the threat to Mississippi River commerce could be substantial. The costs of transporting farm waterborne exports to the Port of New Orleans, for example, would increase if these shipments had to be transferred off of barges and on to trucks.

The situation, once again, highlights the lack of investment in the nation’s infrastructure  and the need for urgent new investment in new roads, bridges, waterways, dams, transmission lines, etc. 

The situation highlights the need for Congress to pass the Biden administration infrastructure bill and begin the process of rebuilding and repairing the nation’s infrastructure including the I-40 Hernando-Desoto bridge linking Arkansas and Tennessee.