Marine Oswego Breakwall Repairs


The USCOE Buffalo district contracted Kokosing to rebuild the Oswego Outer Breakwall after Hurricane Sandy severely damaged the structure.  


The outer breakwall in Oswego NY was built in the 1880’s.  The breakwall had slowly deetiolated and was worsened by Superstorm Sandy in 2012.  The project included adding approximately 115,000 tons of breakwall stone, and 1,000 concrete Dolosse.   It also included a new navigation light and a boat landing.

The breakwall stone came from multiple sources in New York and Vermont. The local stone was trucked to the site and the rest was shipped by rail.  All materials were received at the Port of Oswego, loaded onto barges, and placed by our marine crews.  The bulk of the stone was 8 – 18 ton Armor stone.  Due to quality issues, multiple sources were required to produce 70,000 tons of Armor.

The project also included placing concrete Dolosse on the western end of the breakwall.  The Dolosse were constructed in a pre-cast yard approximately 100 miles from the jobsite.  Due to weight limitations, only 1 Dolosse per truck could be shipped.  Special forms were constructed to make the pieces.  Each unit was reinforced with steel.  

Placement of the Dolosse required a special survey tracking system.  Each unit was placed in a predetermined location designed to populate any given area with a minimum density.  The tracking system included an x,y,z position and a rotational component.  As each Dolosse was placed, the system tracked it’s precise as-laid position, and logged it to a data base.  The software built a virtual image of all placed Dolosse, and assured the required random pattern was achieved.  


The Dolosse’s were an economical solution for the project.  Since their use is limited in the US, the project was also created a case study for future use.


The use of Dolosse is predominately found in areas where quality breakwall stone isn’t readily available.  This system is used throughout the world.

  • Project Name:
    Oswego Breakwall Repairs