A section of roadway rests on the barge that knocked out the supports of the I-40 bridge across the Arkansas River. The piers that collapsed were about 200 feet from the channel.
The collision renewed concerns about the protection of highway and railroad bridges from collisions with vessels. The National Transportation Safety Board recommended that states survey all bridges over waterways to assess the risk of collision with vessels, but the Federal Highway Administration did not adopt this recommendation.
Robert Y. Love, which is owned by Magnolia Marine Transport Co. of Vicksburg, Miss., struck the bridge at 0748 on May 26 as it was traveling upstream at about 4 to 6 knots. The towboat veered out of the navigation channel, and the two barges struck the second and third piers in the 1,988-foot-long bridge, causing a 580-foot-long section of the bridge to collapse, according to the Oklahoma Department of Transportation. As a result, 10 vehicles plunged off the 60-foot-high bridge into the river, killing 14. Four people were rescued by men fishing in the river below the bridge.
The two piers struck were 200 feet from the bridge pier marking the west side of the 300-foot-wide navigation channel. The towboat’s captain told authorities he blacked out just before the collision, according to the NTSB, which is leading the investigation.
A local newspaper, which sat in on a closed NTSB meeting on June 1, reported that Ken Suydam, the NTSB’s chief investigator, said that the towboat’s captain had a heart blockage. The NTSB will neither confirm nor deny the story.
Jennifer Meador, a spokesperson for Magnolia, said that her company could not comment on the captain’s condition before the accident. Meador did say, however, that neither the captain nor the company was aware before the accident that he had a heart condition.
Two weeks after the accident, the captain was being treated at the cardiac unit in a hospital in Jackson, Miss. He had tested negative in alcohol and drug tests performed by Magnolia immediately after the accident, Meador said.
Suydam said that the captain had slept nine hours in the previous two days, but that lack of sleep was not a factor in the accident. About five to 10 minutes before the collision, a crewmember spoke to the captain, who said he was okay, according to Keith Holloway, spokesman for the NTSB.
When the accident occurred, the captain was alone in the pilothouse, Holloway said. The five crewmembers onboard were not hurt.
In addition to the captain’s medical condition, the NTSB will also investigate the history and maintenance of the towboat, Holloway said. Robert Y. Love, a 2,600-hp towboat, was built in 1955 and purchased by Magnolia in 1991.
Holloway also said the NTSB will investigate what factors the age of the Oklahoma bridge and its construction played in the accident. The I-40 bridge was built in 1967 and was rated satisfactory by the Oklahoma DOT. The state’s DOT had done a ship-bridge collision survey of its bridges across the Arkansas River, but concluded the probability of a ship striking the outer pier of the I-40 bridge was small, according to Justin M. Magee, DOT spokesman. All new bridges in the state are built to federal design standards, which take into account ship-bridge collisions, he said.
There were fenders on the upstream side of the two bridge piers next to the navigation channel, but no fenders on the downstream side of the bridge.
Even though the states were not required to do risk assessments in accordance with the NTSB’s 1994 recommendation, some federal agencies did conduct surveys. From 1995 through 1997, a federal task force, including the Coast Guard, FHWA and the Federal Railroad Administration, did assess bridges for ship collision and made improvements on at least 500 bridges, according to interagency correspondence.
Much of the problem is that the FHWA has its hands full replacing obsolete bridges, said Joe Osterman, the NTSB’s director of highway safety. Of the country’s 583,000 bridges, 30 percent are either structurally deficient or obsolete, according to a 1998 survey by the FHWA’s Office of Bridge Technology.
Closeup of the barge’s bow that was deformed by the impact.
The Coast Guard requires some type of fender system on all bridges that cross waterways with commercial navigation, according to Nicholas Mpras, chief of the Coast Guard’s Office of Bridge Administration. But if his office required fenders for every pier of these bridges, the cost would be prohibitive, Mpras said.
When a vessel strikes a bridge, it is often outside the navigation channel, where there are no fenders. “Most of the collisions we have investigated involve a ship collision with a pier that’s not a channel pier,” Osterman said.
That was the case on May 15, 2001, when the towboat Brown Water V, pushing four barges, went about 300 feet off course and struck the Queen Isabella Causeway, which connects the Texas mainland with South Padre Island. A 160-foot-long section of the bridge collapsed. Eight people died when their cars then plunged off the bridge.
On Sept. 22, 1993, the towboat Mauvilla, operating in dense fog, pushed several barges into the Big Bayou Canot railroad bridge near Mobile, Ala. Eight minutes later, an Amtrak train with 220 passengers crossed the displaced bridge and derailed, killing 47 people and injuring 103. The NTSB found that the pilot of the towboat lacked radar navigation competency.
The collision of a bulk carrier with the Sunshine Skyway Bridge in Tampa Bay, Fla., was pivotal to the development of techniques to protect bridges from ships. On May 9, 1980, the Liberian bulker Summit Venture was forced out of the navigational channel by a sudden and severe storm and rammed the structure, taking out a 1,300-foot section of the bridge and killing 35 motorists.
Before that accident, there were no engineering standards for bridge protection or risk assessment for bridge-ship collisions, according to Michael A. Knott, a vice president at Moffatt & Nichol Engineers in Richmond, Va. “The Sunshine Skyway accident was really a turning point in the United States,” Knott said. “It illustrated the fact that we had a problem and didn’t know what to do about it.”
In 1980, Knott was a structural engineer working for Greiner Engineering in Tampa. His firm designed the new Skyway Bridge, and he was project manager for the pier protection system. He also became involved in the effort to create engineering codes to design bridges to better withstand ship collisions.
“In the old days, if a bridge were protected at all, it was usually just the main piers in the channel,” Knott said. But research showed that twice as many accidents happened with ships hitting the approach piers of a bridge. “The situation exists today where we have approach piers, that if they’re even slightly touched by a vessel, then they will collapse,” Knott said.