The South Carolina Department of Transportation (SCDOT) has agreed to a modified plan to complete the painting of the Don Holt Bridge in Charleston County.
The revised plan by painting contractor Eagle Industrial Painting (EIP) addresses the issues that ultimately led to the failure of the original containment system on July 19, 2017. SCDOT suspended work on the upper truss portion of the bridge and a thorough report was conducted by a licensed professional engineer representing Applied Building Sciences (ABS), a leading forensic firm with experience investigating complex collapse claims.
The report concluded that the most probable cause of the containment system failure was the retention of rainwater from a sudden and un-forecasted thunderstorm. The containment system included a tarp to protect passing vehicles during painting of the bridge truss.
The revised plan:
The revised plan changes both the application method and the containment method. EIP will use a roller application method, as opposed to a spray method, to complete the upper truss work. This method was already necessary in some areas of the structure with limited accessibility for the spraying equipment and tight corners and joints. All tests indicate that the coating thickness requirements have been met or exceeded using roller application.
For the top members of the truss, steel rigging cables, nylon netting and tarps will be necessary. However, unlike the original containment system, only the rigging and netting will remain during non-working hours. During nighttime operations, tarps will be spread out over the netting in the areas being painted. At the end of each production shift, the tarps will be removed or furled and secured. This method ensures that no unattended tarps will be left in a condition that could collect and retain water.
The full containment system will still be used on the underside of the truss, where it is shielded from rain by the bridge deck. All of the painting over the navigational channel has been completed, so the remaining work on the underside of the truss is outside of the navigational channel.
While the roller application is more time consuming than spraying, EIP believes the elimination of the time to erect the containment system will offset much of the time impact.
Overhead painting will resume once the contractor has prepared the rigging materials, most likely in the next few weeks. Weather permitting, the remaining work can be completed by the end of the year.
Among the motorists whose vehicles were damaged by the fallen containment system in July, EIP's insurance company reports 12 vehicle owners filed claims. Ten have received payment; two claims are pending.