Climbing Inspection of Bridges

Client: Montana Department of Transportation (MDT)

Statewide, Montana (US)

Since 2008, under three separate contracts, Collins has performed climbing inspections of 21 of the state of Montana’s largest bridges for MDT in the US. The bridge inspections were performed by engineer-inspectors, and have included rope-access techniques to provide in-depth, hands-on, fracture critical inspection of all bridge elements on various bridge types including suspension and above and below deck truss.
 
Collins’ rope-access techniques follow SPRAT and IRATA guidelines, and are used during inspection work for ascending, descending, belaying, rebelaying, deviations, rope-to-rope transfers, aid climbing, and miscellaneous rigging. The use of such techniques to inspect bridges eliminates the need to close down lanes on the bridge or to use expensive snooper trucks during inspection work.
 
The use of rope-access techniques is due to the configuration and size of the bridges—bridge decks typically range from 50 to 150 feet above the waterline, and inspectors rappel over 75 feet to access all structural elements on the bridges. Due to under-deck portions of the structures that are inaccessible via snooper vehicles, inspectors have used beam clamps to slide along the floor beams to inspect the stringers and all associated connections.
 
Collins’ engineer-inspectors performed element level inspections for each bridge inspected. They then produce inspection reports containing evaluations of the overall conditions of the bridges—including photographs, sketches, and diagrams—as well as recommendations for short- and long-term repairs and maintenance. Finally, data is entered into MDT’s database so that reports for each structure inspected may be generated.
 
Typical Scope of Work
  • Performance of rope-access climbing inspections of bridges
  • Element level inspections; in-depth, hands-on, fracture critical inspection of all bridge elements
  • Preparation of reports including photographs, sketches, diagrams, and recommendations for repairs and maintenance
  • Data entry into MDT database