- Company: Crowder Construction
- Industry: Transportation
- Location: Charleston, South Carolina
- Expected Completion Date: July 7, 2014
- Project Website
At the southernmost point of historic Charleston, SC, where the Ashley and Cooper Rivers converge to form the Charleston Harbor, is a seawall called “The Battery.” The wall was originally constructed, in the 1730’s, as a fortified seawall made of palmetto logs and was called Broughton’s Battery. It was rebuilt using stone ballast from arriving ships in the early 1800’s and called “The Battery” because of cannons mounted during the War of 1812. In the late 1800’s and early 1900’s, city leaders rebuilt and reshaped portions of the High Battery and the Low Battery, and created “The Turn.” The Turn is a 120- foot section of wall that joins the High Battery and Low Battery in a radius at the point of the Charleston peninsula.
In October of 2013, Crowder started work replacing a part of history. Nestled in and around priceless antebellum homes and countless tourists, Crowder moved in a 230-ton crane and support equipment to replace “The Turn.” Many meetings were held with local officials and their engineers where we were told “this is the most important project in the City.” The scope of work was to install a cofferdam, demolish the old concrete and pilings, install new pilings and concrete, remove the cofferdam and return the area to the state we found it with minimal disruptions to the residents and the tourists.
What impact does this project have on America?
A quote from a city official in the local newspaper read. “Due to the complex nature and historic significance of the walls, specific construction expertise is required for this project. Only those contractors with significant experience and expertise will be allowed.”
This project exemplifies the history of an early American city. A very complex construction project located in one of the most historic and influential areas of the Carolinas being built under the microscope of local politicians. Crowder not only rose to the challenge, but exceeded the expectations of the owner and all other stakeholders in the project.
The project preserved part of American history that hundreds of thousands of people visit annually.
What interesting obstacles or unusual circumstances did you overcome to complete the project?
Vibration monitoring plans were established to minimize the effects of the work on the rest of the seawall and the homes in close proximity. Equipment and material deliveries were coordinated so that traffic congestion could be minimized. Special concrete forms had to be fabricated to meet the unusual radius and radial profile to the existing wall.
What dangers and risks did you encounter, and describe any extraordinary methods used to keep workers safe?
Crowder designed and installed a sheet pile cofferdam to protect the work area from Cooper river and its six foot tides. The Cooper Marl is a geologic formation specific to the Charleston area that is approximately 50 feet below the water surface. The sheeting was toed into the marl to ensure a water tight seal for the cofferdam.
Early during construction a revolutionary era cannonball was excavated out of the existing battery wall fill. The cannonball was live and had to be dealt with using proper protocols and care. Due to care and effective communication, the project did not experience any delays.
How did you leverage new technologies to work faster and reduce waste?
Crowder had to extract the existing timber piles that were installed around the 1920’s under the existing battery wall. The City and design Engineer wanted all the piles removed prior to installing new prestressed concrete composite piles. Crowder extracted the piles using a vacuum tube to go around the piles and remove them entirely. The process was fast, cost effective and done with very little effort.
Crowder also had a form system designed and built off site to meet the radius and curvature requirements of the new design. The wooden form system was delivered to the site and used to construct the new wall.