In March 2015, Barge Waggoner Sumner and Cannon (BWSC) of Nashville, Tennessee, contacted Collins for assistance in performing an above water inspection of a bridge located within the secured perimeter of Oak Ridge National Laboratory (ORNL) in Oak Ridge, Tennessee. The owner, U.S. Department of Energy, was looking to reopen the bridge to construction traffic during the facility’s deconstruction operations of the K-25 Gaseous Diffusion Plant.
However, during the last recorded bridge inspection and load rating performed in 2005, the bridge was restricted to passenger vehicles only and had since been restricted further to golf carts only in 2010. Additionally, no records were available that demonstrated an underwater inspection of the bridge had ever been conducted. Due to the load restrictions placed on the bridge, it was determined that climbing the bridge was the best course of action. An underwater inspection was added to the scope to give BWSC the necessary data to perform a load rating of the bridge. Over the next several months, the scope of services changed several times. The scope ultimately included fracture critical climbing inspections and acoustic imaging of two bridges within the property. Acoustic imaging took the place of the underwater inspections of both bridges due to contamination concerns in the river bottom’s silt.
In mid-December 2015, Collins’ inspection team mobilized to Oak Ridge to begin the inspections. Daily scoping and safety meetings, onsite training, and contamination testing/verification slowed the inspections considerably. However, all inspections were completed within the original four-day window. Additionally, the inspection reports for both bridges were submitted to BWSC within one week of demobilization from the site. This allowed BWSC to complete their load ratings and submit their findings to the owner by the end of 2015.
Upon completion of the load ratings and further discussion within the project team, the recommendation was that both bridges not be reopened to construction traffic. Collins provided recommendations to ORNL on construction equipment staging locations in order to best proceed with the deconstruction operations of the facility.