Rain to blame for Don Holt tarp failure, report says

Source: WCBD

CHARLESTON COUNTY, S.C. (WCBD) — The South Carolina Department of Transportation has completed its review of the report on the tarp failure on the Don Holt Bridge on July 19.

“The report concludes an accumulation of rainwater resulting from an extreme and unexpected thunderstorm was the most probable cause of the failure of the system,” the SCDOT said in a news release.

The report was conducted by a licensed professional engineer representing Applied Building Sciences. We’re told the company was retained by the insurance company the contractor on the bridge painting project.

Applied Building Sciences found the weight of the rainwater on the horizontal tarp most likely caused the 1” diameter wire rope chokers to fail. The chokers were used to support the suspended platform beneath the bridge’s superstructure.

Maximum wind speeds at the top of the bridge likely reached 58 mph on the day of the incident, according to certified meteorologist, Dr. Lee Branscome. In addition, 1.68 inches of rainfall was recorded within five miles of the bridge between 5 and 6 p.m., the same timeframe as the failure of the containment system. The report concludes that the primary load that resulted in the failure was most likely caused by rain accumulation on the tarp and not the wind loads.

We’re told the painting contractor, Eagle Industrial Painting did now have access to the system during the day to monitor water accumulation, because SCDOT authorized lane closures only at night.

“While SCDOT had not authorized a continuous, permanent daytime lane closure during the painting operation, SCDOT would have authorized emergency lane closures for tarp repairs or de-watering had it been requested. SCDOT did not receive an emergency lane closure request from EIP on July 19, 2017, which is understandable due to the suddenness and unexpected nature of the storm,” a news release added.

Among the motorists whose vehicles were damaged by the fallen containment system, EIP’s insurance company reports 12

Twelve vehicle owners filed claims for damages, according to Eagle Industrial Painting. We’re told ten have received payment.