Cargo boxes at Wando Welch

The State Ports Authority moved a record number of cargo containers through the Port of Charleston in April. Provided/State Ports Authority

The State Ports Authority will keep the gates at its busiest terminal open for extended hours as long as the nearby Wando River bridge is closed so truckers will have flexibility in moving the record amount of cargo that's passing through the Port of Charleston.

"We'll listen to the truckers in terms of what they're seeing and what they need," CEO Jim Newsome said Thursday. "We'll do what we have to do to support the movement of cargo that comes through our terminal, that's the bottom-line message."

Starting Monday, gates at Wando Welch Terminal in Mount Pleasant will be open from 3 a.m. to 5 p.m. on weekdays and from 6 a.m. to 5 p.m. on Saturdays. The SPA also has extended hours at the terminal through this weekend.

The move follows Monday's closure of the James B. Edwards Bridge over the Wando after transportation officials learned one of the steel cables supporting the span had snapped. There also is corrosion on some of the other cables. Repairs won't be completed until June 11, according to the latest estimate.

The bridge is a major traffic artery for truckers bringing cargo to and from Wando Welch, and its closure is forcing them to take long detours to reach Interstate 26. All the while, big container ships are bringing more cargo for them to haul.

The SPA on Thursday said it moved the equivalent of 196,439 20-foot shipping containers in April — a record for the month and a 3.8 percent increase from the same period a year ago.

While bridge issues have hampered traffic outside Wando Welch, Newsome said trucks and cargo continue to move smoothly within the terminal's gates.

"I'm not seeing any backups. The main constraint is long times on the road" for drivers, he said.

Newsome urged warehouse operators in the Charleston region to adjust their schedules so truckers using the port's extended gate hours will have a place to drop off their cargo.

"If the warehouse doesn't open until 8 o'clock, it doesn't do a whole lot of good to get a container at 3," he said.

We're starting a weekly newsletter about the business stories that are shaping Charleston and South Carolina. Get ahead with us - it's free.

Extending gate hours is the SPA's only major option to keep trucks and cargo moving in and out of Wando Welch, which isn't served by rail.

"Unfortunately, there really isn’t anything we can do as there is no rail service on that side of town," said Jeff McWhorter, president and CEO of the state-owned Palmetto Railways. "I am hearing the port and the trucking companies are doing a great job keeping things fluid given the circumstances."

The authority has discussed using barges to move containers from Wando Welch to a transfer hub Palmetto Railways plans to build on the Cooper River in North Charleston, but Newsome said no infrastructure is in place to make such a plan viable for several years.

"It's not a short-term solution" to the bridge woes, he said.

Maritime industry analysts say any cargo delays that might be caused by the bridge closure won't have a lasting impact.

"Any diversions from the Port of Charleston would likely be short term, as the port remains a major gateway for the U.S. East Coast," said Tan Hua Joo, executive consultant with Alphaliner.

Reach David Wren at 843-937-5550 or on Twitter at @David_Wren_