Photo: HNTB

Crossing designs are evaluated by the captains who will guide ships beneath them.

The overall project includes an 80- to 90-mile controlled access toll roadway that will encircle Louisiana’s capital city metro area and alleviate congestion by providing additional capacity to Interstates 10 and 12 and alternate routes for local traffic.

The first 25-mile section “has been broken out into an independent project,” which means it can advance ahead of the rest of the job,” says Bob Schmidt, assistant vice president and BR Loop project manager, HNTB Corporation, Kansas City, Mo.

HNTB has a $4.1 million contract with the Capitol Area Expressway Authority, the regional toll agency, to perform project planning and deliver environmental impact statements as required by the National Environmental Policy Act. HNTB is scheduled to deliver the Tier 1 EIS for the whole project by the first quarter in 2011.

Breaking out this 25-mile section will allow HNTB to complete the Tier 2 on that portion and move into design earlier than it would take for the whole project, Schmidt says. “We’re developing that piece of it to be done with traditional municipal toll roads or public private partnerships,” Schmidt says. “Our plan is to actually solicit concessionaires for involvement by mid-2011.”

HNTB completed a big piece of the Tier 1 puzzle in March, when it vetted two proposed Mississippi River Bridge crossings at the Maritime Pilots Institute in Covington, La.  The BR Loop project includes four proposed Mississippi River Bridge crossings. Two have already been vetted with shallow draft navigation interests and all other interested parties. Deep draft navigation interests expressed concern about disruption to river traffic with what is called the Red Eye crossing. HNTB wanted to get feedback from pilots who will be navigating vessels past either that bridge, or an alternative crossing at Missouri Bend.

On March 11, four ship pilots from the New Orleans-Baton Rouge Steamship Pilots Association met with members of HNTB, the Louisiana Dept. of Transportation and Development, the U.S. Coast Guard and the Capital Area Expressway Authority to test what navigation would be like with each bridge. Captains Marvin Bowman, Ron Grue, Henry Shows and Robert Streckfur piloted a 45,000-ton and 110,000-ton ships (equivalent to an oil tanker) along the Mississippi past the Red Eye and Missouri Bend bridge crossings using a virtual reality simulator at MPI.  The pilots’ job was to test for safety and navigability around the bridge piers.

“The Baton Rouge Loop bridges could change the traffic flow between ships and barges if the piers aren’t in just the right place,” Capt. Bowman says.

The simulator, which is used to train deep draft pilots, simulates the actual Mississippi River from north of Baton Rouge to the Gulf of Mexico, including water flows, existing docks and other structures, and geographic elements, says George Burkley, MPI executive director. The simulator can be programmed to include as much traffic and weather conditions as desired.  

“Even though the river is very big (as wide as 2,400 ft in some areas), the ditch we have to stay in is very narrow,” Capt. Grue says. The actual ship channel that large vessels must travel is only 500 ft. wide. Loaded ships may be as deep as 40 ft, slowing down movement and response time.

The U.S. Army Corps of Engineers only guarantees the channel is dredged to 45 ft, Burkley says. “One ship could get stuck and block that channel and shut down commerce in the whole country.”  

The NOBRA Pilots had input in the placement of the bridge piers, Capt. Shows says. Their input actually prompted HNTB to model the Missouri Bend option, which has longer spans than the Red Eye, says Gordon Glass, bridge section manager, HNTB. The Red Eye crossing’s main navigation span is 1,700 ft. The Missouri Bend alternative has a 1900-ft main span. “By doing these simulations, we are trying to identify what the environmental process calls fatal flaws,” Glass says.

The MPI’s Burkley will interview all the pilots about their experience navigating both crossings and deliver a report to HNTB. “Then any identified issues go into a matrix of factors including land use, economics, cost, and number of people displaced,” Glass says. “They all get weighed in deciding whether to carry alternatives forward.”