NORTH AUGUSTA -- Every day, the train bridge spanning the Savannah River at Sixth Street in Augusta supports thousands of tons of weight.
The 1,193-foot bridge is owned by Norfolk Southern, which runs six trains over it daily, each train between 75 and 95 cars long. The diesel locomotives alone weigh 195 tons each.
And in seven months, the bridge will be 100 years old.
The oldest parts of the bridge were built in 1899, and new spans and components were added in 1911, 1914 and 1931. In 1971, Norfolk Southern rebuilt the trestles -- the framework of beams atop the bridge.
Railroad companies inspect their bridges for structural integrity every year, but looks aren't on the checklist, said C.T. Goewey, chief engineer of bridges and structures for Norfolk Southern.
"We'd love to have them all fully painted, but that's expensive," he said.
If a bridge is well-maintained, old age doesn't necessarily contribute to deterioration, he said. Older bridges designed after 1900 are usually good for modern-day loads, because they were built for heavy steam locomotives, he said.
"Age is not necessarily an indicator of capacity," he said.
The bridge connects the railroad company's Columbia line to Augusta. The structure carries cars loaded with paper, wood chips and chemicals. It's a drawbridge, but the part of the bridge that rose to accommodate tall boats passing on the river hasn't been lifted in 40 years, according to the company. The machinery that lifted it has been disabled and left to rust.
The company owns two other bridges in Aiken County: a 117-foot bridge over South Carolina Highway 421 built in 1899 and remodeled in 1925 and 1977; and a 154-foot bridge over South Carolina Highway 118 built in 1976.
CSX also owns a railroad span over the Savannah River, one of its three bridges in Aiken County. The river bridge was built in 1973, and like the company's 1974 bridge in the area, it's made of concrete. The third bridge is a timber bridge built in 1946, but it's only 50 feet long, and all its supports were replaced in 1993, said Jane Covington, spokeswoman for CSX.
All the company's routes are divided into territories which are inspected twice a week, she said. All of CSX's bridges are inspected by engineers at least once a year, she said.
Norfolk Southern also does formal inspections of its bridges once a year.
Bridge inspectors and technicians look at and measure every component of the bridge that affects its structural integrity, which often requires a lot of climbing around the bridge or riding in buckets attached to cranes, said Gordon Davids, chief bridge inspector for the Federal Railroad Administration.
Their reports are compiled and sent to engineers for review. A complete inspection can take as little as several days for a small bridge; larger bridges can take weeks.
"The inspector knows what it's supposed to look like, and they measure it every time they go out," Mr. Davids said.
The inspections are done mostly by the railroad companies themselves; the FRA audits their work. Because the safe condition of the bridges is important to running a profitable railroad, the railroad companies do a good job of inspecting them, Mr. Gordon said. If the FRA mandated inspections, it would have to specify how often bridges must be inspected, what they should be inspected for and a host of other details.
"Before writing those regulations, we must justify them and show they would have a positive benefit," Mr. Davids said. "We could not justify those regulations."
There has not been a train death resulting from the structural failure of a bridge since before World War II, when the FRA began to keep records, he said.
Deaths on train bridges tend to involve trespassers and alcohol, not the integrity of the structure, said Bob Auman, spokesman for Norfolk Southern.
"That's where people are hurt or killed," he said.