Franklin Falls Dam

Franklin Falls Dam

Franklin Falls Dam

  • Custom designed and fabricated hydrodemolition robot that was suspended over the dam wall.
  • Project was completed with zero recordable safety incidents.
  • Project was completed on time with all wastewater treated to allow for safe disposal.
Location
Franklin, NH
Project Team
  • Owner:
    U. S. Army Corps of Engineers
  • General Contractor:
    Proshot Concrete, Inc.
  • Engineer of Record:
    U. S. Army Corps of Engineers
  • Hydrodemolition Company:
    Rampart Hydro Services

The Franklin Falls Dam in Franklin, NH, on the picturesque Pemigewasset River, was originally built in the early 1940’s. Over time the concrete of the East Inlet Channel Wall had deteriorated, necessitating Rampart’s specialty hydrodemolition capabilities, so the wall could receive a facelift of new shotcrete. Approximately 400ft of linear wall required to be demolished at a depth of 3″ for a vertical height of ~30ft. To add complexity to the work, there were various areas where the concrete was heaved and/or delaminated, as well as areas where the concrete had already spalled. There were sections of the original degraded concrete, as well as previously repaired sections of gunnite which had a much higher compressive strength. These varying conditions would require an experienced operator with versatile equipment, to continually monitor & adjust throughout the demolition process as needed.

Rampart Hydro Services provided Proshot Concrete with a comprehensive hydrodemolition plan for safely removing the deteriorated concrete. This plan included the use of a Rampart custom-designed and fabricated hydrodemolition robot that was unique to this project. In addition to the customized equipment, Rampart was able to provide an experienced crew of hydrodemolition experts with many years of experience to perform this challenging work under harsh conditions.

Rampart’s technicians & equipment would be at the top of the wall & the hydrodemo equipment would need to be carefully positioned along the height of the wall & along its full length. A plan was developed to suspend a hydrodemolition tractor over the dam wall and demo from bottom to top.

Rampart successfully removed approximately 5,500 SF of concrete to a 3.0″ depth and treated all the associated wastewater to allow for safe disposal.  The project was completed safely with no harm to employees as a proper fall protection plan was executed to eliminate fall exposure where possible and to provide proper fall arrest systems as needed.  Days of hail & lightning storms delayed the start of the job, but the crew quickly got the custom equipment exceeding initial production expectations resulting in another successfully completed hydrodemolition project.