A Graceful Link
North America's longest cable-span
bridge opens in Charleston, S.C., just four years from award
of the initial contract
By Debra Wood
|The diamond shape of the towers,
chosen by the community, gives the bridge its signature.
Historic Charleston, S.C., now has a
landmark northern gateway with the summer opening of the newest
bridge over the Cooper River. Four years after receiving the
green light, its design-build contracting team finished construction
on Charleston's 3.5-mile, $540-million Arthur Ravenel Jr.
Bridge for the South Carolina Dept. of transportation. The
eight-lane bridge is the longest cable-stayed bridge in North
The bridge over the Cooper River opened
to traffic in mid-July after a week-long community celebration.
"It's a monument that will be here
forever," says Wade Watson, project manager for Palmetto
Bridge Constructors, the design-build joint venture of Tidewater
Skanska Inc., Virginia Beach, Va., and Flatiron Constructors
Inc., Longmont, Colo. "It's built to withstand anything
that can float in the water." It is designed to withstand
Category 5 hurricanes, an annual threat, and major earthquakes
such as the one that decimated the city in 1886.
|Palmetto Bridge Constructors self-performed
80% of the work. At peak construction, 600 PBC employees
and 200 subcontractors worked on the 3.5-mile-long bridge
and its access roads.
"We had to have a strong, robust
bridge and it had to be flexible and able to bend and move
and remain standing," says Bobby Clair, SCDOT director
of engineering and special projects. "Blending that together
created a real issue for the designers."
PBC selected Parsons Brinckerhoff, New
York City, as a design partner. San Francisco-based MacDonald
Architects consulted and suggested eye-appealing features
such as sloping light poles on approaches to the bridge to
match the cables' slope. The firm also suggested slanting
piers to echo the diamond shape of the bridge's two towers,
which anchor the cables that support the road deck.
"Even though this was cost-driven,
we were able to include a lot of nice architectural features
to enhance the look of the bridge," says Michael Abrahms,
technical director of major bridges for Parsons Brinckerhoff.
SCDOT considered a wide variety of solutions
to replace the aging and narrow John P. Grace Memorial and
Silas M. Pearman bridges, including a tunnel, but environmental
impact studies favored a single bridge.
SCDOT consulted with neighboring communities
during planning and the public chose the signature 575-ft-high,
diamond-shaped towers. That added a degree of difficulty to
the job, Watson says.
|The bridge's 1,546-ft main span is
supported by two 575-ft-high, diamond-shaped towers.
TYLI/HDR, a joint venture between T.Y.
Lin International's Alexandria, Va., office and Omaha-based
HDR, provided design review, engineering and inspection services
At a total cost of $632 million, the bridge represents the
largest single transportation infrastructure project completed
by SCDOT. It is 2.5 times the department's annual statewide
construction budget. At the job's beginning, when the state
was ready to proceed with bids, it did not have all of the
funds to complete the structure.
"We thought we could build four lanes, and if we came
up with the money during construction, we could probably do
the other four," says Clair. "But by doing design-build,
we could set the wheels in motion."
SCDOT moved forward with the help of a $325-million grant
from the South Carolina Infrastructure Bank, established in
the late 1990s. The bridge's namesake, state Sen. Arthur Ravenel,
spearheaded campaigns to create the bank and build the bridge.
At the last minute, the state secured a 25-year federal loan
for an additional $215 million, allowing it to proceed with
all eight lanes, ramps, a frontage road and bike and pedestrian
Grand opening: July 16, 2005
> Connects Charleston and Mt. Pleasant along Highway
> Eight 12-ft-wide traffic lanes
> 1,546-ft main span
> 575-ft-tall towers
> Road deck rises 200 ft above the median high-tide
> 128 individual bridge cables
> Cables formed by 90 seven-wire strands
> Each cable holds more than
1 million lbs
> White pipes range in diameter from 12 to 20 in.
> 12-ft bicycle and pedestrian lane
> 300,000 cu yd of concrete
> 50,000 tons of reinforcing steel
> 40,000 tons of structural steel
> More than 400 drilled
Clair, Watson and Abrahms say that the design-build approach
worked well but had its risks.
"It's wonderful, great for the owner, but it puts a
lot of risk on the contractor and makes the job more difficult
because you are trying to procure and build while design is
still going on," Watson says.
Design-build also changes the design dynamics tremendously,
Abrahms says. "In the past, you worked with a government
agency and made decisions with the agency," he says.
"Now, all of a sudden, someone else, the contractor,
is at the table and he tends to have a lot of opinions."
But Abrahms also sees the positive. "It allows the owner
to select what he thinks is the most well-qualified team,"
he adds. "I think that benefits the industry."
SCDOT employed a formal partnering program on the job. Senior
management met every three months at retreats to address anticipated
problems. Managers responsible for each issue reported back
at the next meeting.
"We stayed until we had a solution to every problem,"
Clair says. "On most of the design issues, there were
great discussions and debate. When video and teleconferences
weren't working, I would call an onsite meeting, and we'd
sit down face to face and find out what the issues were. Seldom
did it take more than an hour to work out the details."
|The cable anchors connect the 128
individual bridge cables to the bridge deck. Each of the
cables was formed by 90 seven-wire strands and can hold
1 million lb.
PBC received the notice to proceed on July 16, 2001, with
a contract completion date of July 2006. But PBC had a plan
to build it in four years, not five, decreasing the cost of
"We split the project into five jobs-each interchange,
each high-level [approach] and the main span," Watson
says. "There were five budgets, five schedules, five
sets of equipment and five sets of supervision. We had very
little overlap and ran five simultaneous $150-million construction
Demolition of homes began in fall 2001 and the first foundation
work started in April 2002. Design called for a drilled-shaft
foundation, chosen over pile driving to decrease noise for
nearby residents and create less disturbance to the existing
bridges. The site had soft soil, forcing crews to drill 240
ft to a deeper clay layer. Some of the shafts are 12 ft in
Steel girders on the high-level approaches sit atop a series
of columns and pier caps. Concrete girders were used on the
The 1,546-ft main span hangs between the diamond-shaped support
piers by 128 cables, which are made of seven-wire strands
twisted together and enclosed in a high-density polyethylene
pipe. The pipe ranges in diameter from 12 to 20 in.
PBC self-performed 80% of the work. At peak construction,
600 PBC employees and 200 subcontractors worked on site. PBC
hired as many locals as possible before bringing in people
from outside areas.
"We spent a lot of time with the community in public
relations and did things to lessen the impact of construction,"
Clair says. "They supported us all the way through, and
that was a big part of the success of the project."
|The bridge decks, which rise 200
ft above the median high-tide mark of the Cooper River,
contain more than 300,000 cu yd of concrete.
The bridge displaced residents of a low-income neighborhood,
and SCDOT officials included in the contract a requirement
to train local residents in building trades. PBS provided
a two-week course to teach job-readiness skills and safety
to 82 unemployed or underemployed residents, then offered
on-the-job training in crafts. Sixty-two of the people obtained
journeymen's status in at least one job area.
"We exceeded the state's goal," Watson says. "And
had some good success stories."
New hires, working in the special program or just new to
the jobsite, wore a hard hat with a green stripe that let
foremen know to send an experienced hand for certain tasks.
Workers strove to prove they knew the safety rules and earn
the removal of their stripes. The team also used incentives
and training to promote safety. The bridge was completed within
budget, with no claims or issues between PBC and SCDOT. It
opened as scheduled on July 16, after a week of special events.
"I was excited to be here, in my home state, building
a significant bridge, a landmark bridge," Watson says.
"It was a very challenging project, and something I am
proud to be part of."
|The $632-million, eight-lane bridge,
which connects Charleston and Mt. Pleasant along Highway
17, is the largest single transportation infrastructure
project ever completed by the South Carolina Dept. of
Transportation. It cost 2.5 times the department's annual
Owner: South Carolina DOT
Designer: Parsons Brinckerhoff, New York
Design Review and Inspection: TYLI/HDR, a joint
T.Y. Lin International, Alexandria, Va.; and HDR, Omaha,
General Contractor: Palmetto Bridge Constructors
(PBC), a joint venture of Tidewater Skanska, Virginia
Beach, Va.; and Flatiron Constructors Inc., Longmont,