A TEXAN viaduct which collapsed after a barge strike in 2001, killing eight people, remains vulnerable to future strikes, the US Coastguard revealed last week.
In its official investigation into the accident, the Coastguard urged Texas highway authorities to install large concrete 'collision prevention cells' either side of the channel on the bridge approaches.
Two 24m sections of the Queen Isabella Causeway collapsed in September 2001 when a tugboat hauling four loaded barges strayed out of the navigation channel and hit an unprotected pier (NCE 20 September 2001).
The accident occurred at 2am.
Motorists on the unlit bridge failed to see the collapsed section and plunged into the water.
The report revealed that the tugboat was rounding a bend in the navigation channel when it got caught by a cross current, which pushed it 115m to the left of the channel.
It blamed the accident on the tug captain's lack of reasonable care in failing to determine the strength of the current before entering the bend.
It warns that the location of the bridge makes it vulnerable to future catastrophes.
'Mechanical failures such as a loss of steering or loss of power could result in a similar catastrophe any time the current is running hard and despite the degree of care exercised by the vessel's operator, ' says the report.
The United States has been plagued by bridge bash incidents.
In 1980 the US Army Corps of Engineers specifically warned against building bridges on bends or in areas of strong cross currents.
The Queen Isabella Causeway Bridge was completed in October 1974 at a cost of £7.5M.