Replacing the Bridge Pier Fendering System at Charleston Marina

For more than a decade, the city of Charleston SC, has longed for the expansion of its marina, a labor of love encompassing countless smaller projects along the way. Case in point: To complete the expansion of the Charleston City Marina, a century-old shipping channel must be carefully relocated westward. A team from Crowder Construction recently made a significant contribution to this delicate work.

The team, led by Project Manager Mitchell Davis, was recruited to dismantle a pre-existing bridge pier fendering system beneath the James Island Expressway (HWY 30) Bridge, right on the Ashley River. From there, the task was to replace it with an entirely new pier fendering system, complete with navigational lighting. This replacement project was deemed essential to the logistics of relocating the shipping channel, and thus to the broader project of marina expansion.

A Project of Enormous Scope

The sheer scope of this project is striking, and more complicated than first meets the eye.

“This project includes the drilling and installation of four drilled shafts, four concrete caps on each drilled shaft, two each of cast-in-place concrete beams between the caps, and approximately 385,000 lbs of treated structural timber attached to the face of the concrete beams,” Davis explains. “These timbers extend to a depth of 50’ below the water line. Incidental to the project is marine access to include cranes on deck barges, material deck barges, hopper barges, establishment of a marine terminal, and daily crew access. And that’s to say nothing of demolition and removal of the old fender.”

As with any project of this magnitude, there were several obstacles for the Crowder team to overcome.

The first was marine access. “To mitigate the marine access challenge, Crowder partnered with several marine outfits in Charleston to leverage their resources,” explains Davis. “Barges were loaded in Yonges Island which is 25 miles south of the project and pushed by tugboat to the project site, a three-hour boat ride. Spoils from the drilled shaft were unloaded at a dock of the Cooper River in Goose Creek, which is 25 miles north of the project. This was another three-hour ride via

Addressing Obstacles

tugboat. Tugboats were also used to move from structure to structure. Lanes on the bridge above were also shut down periodically at night to receive small equipment deliveries and materials.”

Placing concrete under the bridge was another obstacle. Says Davis, “We developed a plan to position a 42-meter pump truck on the bridge above during a lane closure. This machine pumped the concrete into a ‘mini placer’ that was located on a barge under the bridge that placed the concrete into the 93’-long formwork system.” The placement of the pump truck required analysis from a registered engineer, ensuring its safety on the deck of the bridge.

But the biggest problem may have been placing formwork under an existing bridge, where there was very limited overhead space. “This was challenging from both a planning and execution standpoint,” comments Davis. “No on-the-shelf solution existed.” But through months of planning and close collaboration with their supplier, the Crowder team was able to develop their own solution that did work, and to execute it effectively without any project delays.

Historic Results

All this hard work ultimately serviced the revitalization of Charleston’s so-called “Mega Marina,” one of the largest marinas in the Southeast and among the most-visited marinas in the entire country, thanks in large part to its proximity to historic downtown Charleston.

According to Davis, the success of this project came down to a full-team effort. “The estimating team put together a successful bid to get the job, the management staff spent countless hours procuring barges, and the team in the field worked days and nights to build a very unique project that was different from most things we build.”

Project Manager

Mitchell Davis

Project Director

Thomas Horrell

Site Superintendent

Pat Merli

Structural Superintendents

William Culbertson

Nate Carmona

General Superintendent

Michael Wilson

The Team

Project Engineer

Gabriel Matos Negron

Safety Engineer

Gary Hall

Civil Foreman/Crane Operator

Tommy Henson Foreman

Pa Comma

Structural Leadman

Robert Narvaez

Leadman

Marion Holmes

Carpenter

Darrel Collins

Concrete Finishers

Ebrima Jammeh

Clement Tucker

Concrete Helper

Billy Goggins

With much appreciated help from:

Rich Hauser and Robert Cooper