Bridge inspection is an important part of what we do here at Hoyle, Tanner. It is also a vital part of ensuring the safety of the traveling public across the country. You might not realize it, but chances are every time you get in a car you drive across one or more bridges. Per the federally enacted National Bridge Inspection Standards (NBIS) every bridge, big and small, old and new, needs to be inspected on a biennial basis. As you can imagine, this is a huge undertaking for each state’s department of transportation (DOT), and each DOT is looking to inspect bridges faster, more cost effectively, and in less disruptive ways as to not impact the day to day usage of the bridge.
A dynamic, rapidly growing bridge inspection method is to “climb” the structure using rope access techniques. Rope access can best be pictured as a mixture of rock climbing and bridge inspection. The inspector is suspended from two ropes and can either ascend, descend or climb along the bridge. Certain bridges can often have elements that are inaccessible or uneconomical to inspect with traditional methods, such as rigging or the use of under bridge inspection vehicles. Rope access can be tailored for countless geometric challenges, which allows for a detailed, hands-on inspection of every bridge element. In other words, rope access allows inspectors to go anywhere and see any part of the bridge.
Recently a team of five Hoyle, Tanner bridge inspectors including three SPRAT1 and/or IRATA2 rope access inspectors completed a bi-annual inspection of the Memorial Bridge in Augusta, Maine. This 2,100 foot long, 75 foot high historic deck truss bridge posed many challenges for bridge inspection access. Access from the ground below was limited because part of the bridge is over the Kennebec River, and access from above was prevented by a tall chain link fencing that runs the entire length of the bridge. Most importantly, this bridge is a vital transportation route in the heart of the state capital making closing all or part of the bridge to traffic undesirable. Utilizing rope access techniques, we were able to perform a hands-on inspection of every member of the bridge from below the deck and above the river. Rope access allowed for a faster and more cost effective inspection than the traditional methods typically used.