story by Ryan Saylor
rsaylor@thecitywire.com
It was just late last month that two barges went on a directionless journey down the Arkansas River in Little Rock, striking the Interstate 30 bridge and a pedestrian bridge near the Clinton Presidential Library after breaking free from a tugboat.
While five bridges were initially shut down, it was determined that damage was not severe enough to close the bridges beyond the night of Aug. 24, when the accident occurred.
But the runaway barges brought back memories of May 26, 2002, when a barge struck the Interstate 40 bridge near Webbers Falls, Okla., upstream from Fort Smith on the Arkansas River. The accident resulted in 14 deaths after a 580-foot span of the interstate plunged into the river below.
With that in mind, has anything been done to provide better collision protection along the river?
According to District 4 Engineer Chad Adams of the Arkansas State Highway and Transportation Department, many of the bridges along the Arkansas River already have "pre-protection" cells designed to prevent barge-bridge collisions from occurring.
From Ozark to Fort Smith, there are five bridges that span the Arkansas River and Adams said three of the bridges have the "pre-protection" cells. They include the Arkansas River Bridge in Ozark and the Midland and Garrison Avenue Bridges in Fort Smith.
Gene Higginbotham, executive director of the Arkansas Waterways Commission, said the cells are round and located in the river.
"It's a round cylinder filled with all sorts of material," he said. "Their sole purpose is to protect that bridge structure. It hits that and the current will take it down stream. But it protects that bridge structure."
Another bridge in the area that has a protection system is the Arkansas Highway 59 bridge over Lock and Dam 13 near Barling, Adams said.
"That comes up out of the water, on the upstream side," he said. "There is a large pointed piece of concrete that extends out into the river in advance (of the bridge), so if something were to flow down and hit it, that would take the impact."
As for when the barriers were installed, Adams said that was not so clear, adding that the best estimate of when some protection systems were installed was the late 1960s or early 1970s.
The only bridge not to have a protection system of some sort from Ozark to the Oklahoma border is the Interstate 540 bridge. As for why, Adams said it had to do with design.
"I-540 does not have the pier protection system. There's certain requirements, items that go into consideration as to whether it's needed," he said. "Some of the newer bridges are designed to withstand the impact."
Besides the 2002 collapse in Webbers Falls and the August accident in Little Rock, it is rare to have a runaway barge along the river, Adams said, adding that within the last nine years, he could only recall an incident from April 25, 2011, when flooding rains caused a barge to break loose near Fort Smith, resulting in a shutdown of the Garrison, Midland, I-540 and Barling bridges until a runaway barge could be secured.
Regarding concerns about the stability of bridges should an accident occur, whether it is known to the AHTD, Adams said all bridges are inspected every 24 months unless it is a bridge that has been singled out for increased scrutiny. In the case of last month's accident in Little Rock, initial inspections occurred following the accident prior to the numerous bridges along the river re-opening.
But Adams said residents should not anticipate a potential accident resulting in loss of life or catastrophic damage like what was seen 11 years ago, saying that the accident last month shows that Arkansas' bridges are ready for any sort of accident that may come.
In order to keep that safety record, Higgenbotham said his organization would continue to work with the state, as well as engineers and designers working on future bridge projects to ensure safety.
"We want our bridges to be safe and (and to have) good navigation channels so everyone travels safely over and under the bridges."