Roanoke Times
Copyright (c) 1995, Landmark Communications, Inc.
DATE: WEDNESDAY, June 6, 1990 TAG: 9006060465
SECTION: NATIONAL/INTERNATIONAL PAGE: A/12 EDITION: EVENING
SOURCE: Associated Press
DATELINE: WASHINGTON LENGTH: Medium
The National Transportation Safety Board on Tuesday blamed erosion from a shifting river channel for the April 1, 1989, collapse of a U.S. 51 bridge over the Hatchie River, 45 miles north of Memphis.
"It certainly raises a serious concern with me about how much damage may have been done with flooding in Texas and the South," NTSB Chairman James Kolstad said. "I'm concerned that some of these bridges may be put back into service without adequate inspection."
The board called for a modification of federal bridge inspections standards to require underwater inspection of bridge parts exposed to "excessive water depth or turbidity."
It also asked the Tennessee Department of Transportation to follow up bridge inspections with further work by divers when there are doubts about submerged elements.
The board cited the 54-year-old Hatchie bridge's simple design as a contributing factor in the accident which caused vehicles to plunge into the river from the highway's two northbound lanes.
A newer southbound span remained intact, but board investigators said its construction in 1974 accelerated movement of the river channel, which had changed 83 feet from the time the northbound bridge was constructed in 1936.
The board cited the Tennessee Department of Transportation for failing to evaluate and correct problems found in inspections dating back to 1979.
A survey last year by the National Association of Counties estimated that 165,000 bridges need repair or replacement, with some states having up to 90 percent defective bridges.
by CNB