Average size of vessels on waterways makes bridge collapses unlikely in Missouri, MoDOT engineer says

ROCHEPORT, Mo. (KMIZ)

There are more than 10,400 bridges in Missouri. Two hundred of those bridges are considered “major bridges” by the Missouri Department of Transportation, or bridges that are more than 1,000 feet long. There are a lot of factors that go into designing and building one of these bridges, but one of the biggest priorities is safety. 

"I think people need to understand that the first thing that we take into account with every bridge,” MoDOT Assistant Chief Engineer Eric Schroeter said.  “Our families drive over them as well. 

Unfortunately, there are some things you just can’t plan for. Glenn Washer, who teaches Civil and Environmental Engineering at the University of Missouri says that includes a container ship crashing head-on into the Francis Scott Key Bridge in Baltimore on Tuesday morning, which caused the 1.6-mile bridge to collapse in an instant. Six people are presumed dead, according to CNN.

“A ship that size hitting it (a bridge) that directly is not something you’d necessarily expect or design to,” Washer said.

The largest types of boats on Missouri waterways come in the form of barge tows, which also present one of the biggest risks to bridges. Bridge collapses like the one in Baltimore are highly unlikely due to the difference in size of the average vessels that travel the waterways, according to Schroeter. However, collisions have happened. 

“We have had cases where a barge gets loose or something loses power and strikes a bridge so we design for some of that but you can’t foresee everything,” Schroeter told ABC 17.  “That’s why every time a strike happens we do close down a bridge to make sure it’s safe before we reopen it.” 

Schroeter adds that major bridges are designed with navigation in mind, and MoDOT works with the Coast Guard and engineer corps to make sure each bridge is up to the national standard, easy for boats to pass through, and are well-lit at night.

The Department also has to take the weather into account. The bridges must be strong enough to handle earthquakes or flooding. Another factor is ice. During the winter months large chunks of ice bash along the side of a bridge. If the current is strong enough it can cause damage. 

“We design ours to deal with ice that flows down the river and ice that builds up during the winter time to make sure our bridges can withstand the impact and force of all that,” Schroeter said 

Washer has done work on the Francis Scott Key Bridge before and says that it met the national standards when it was built in the 1970s. The bridge is also up to code, according to Maryland Gov. Wes Moore. 

Washer said that there are a lot of major bridge projects going on in Missouri in the past couple of years, including the Rocheport Bridge -- that goes over the Missouri River on Interstate 70 -- that are helping to replace some of the older more at-risk structures. 

“It’s always possible because you have a bridge with a pier in the water. That’s a natural risk,” Washer said when asked about the chances of a collapse happening in Missouri. "Any bridge presents a certain element of risk, but I think it is a diminishing risk over time. Older bridges are replaced, new bridges have more aggressive protection systems; and in some cases, a little stockier foundations, as well, more conservatively designed than they might have been 50 years ago.”