Last spring, divers hauled 30 tons of rusty iron -- encrusted with barnacles, oysters and other marine life -- from the bottom of Chesapeake Bay, where they had lain since 1850, when the side-wheel steamer Columbus burned and sank.
Now scientists in New Orleans will be spend three years restoring the shapeless hunks of metal into one of the most important marine artifacts ever recovered from Maryland waters -- the only wood-fired, cross-head steam engine known to exist.
Representatives of the Army Corps of Engineers and the Maryland Port Administration, which sponsored the $364,000 project, released videos of the recovery yesterday.
The restored engine, 65 feet across and 40 feet high, will eventually be a centerpiece in the atrium of the Columbus Center for Marine Research and Exploration, now under construction on Piers 5 and 6 in the Inner Harbor.
R. Christopher Goodwin, head of the Frederick-based company hired to make the recovery, said the engine pieces, some of which had degraded from iron into fragile graphite, were brought ashore at the Army depot in Curtis Bay.
There, scientists wrapped the pieces in burlap and sprayed them continuously with water to prevent them from drying out and crumbling before they could be trucked in special beds to the International Artifact Conservation and Research Laboratory Inc. in New Orleans.
The laboratory, which built oversize tanks for the project, specializes in metal conservation and restoration. Mr. Goodwin said that as much as 60 percent of the engine can be preserved.
Restorers will have to fabricate some new parts, particularly bolts, to replace missing pieces and to hold the engine together.
Archaeologists have called the Columbus' massive engine a missing link in the evolution of American steamship technology.
Charles Reeder built the Columbus in 1828, 21 years after Robert Fulton launched the first commercially successful steamboat, the Clermont, on the Hudson River. The Columbus' engine had a steam-powered piston 4 feet in diameter moving inside an 18-foot-high iron cylinder. The piston pushed an overhead, T-shaped bar made of iron and wood -- known as the cross-head. The cross-head was set in vertical tracks on a A-frame to turn the side wheels and propel the vessel.
The Columbus hauled cargo and passengers on the bay between Baltimore and Norfolk until the night of Nov. 27, 1850, when it caught fire and burned. The wreck sank in 60 feet of water south of Point Lookout in St. Mary's County. Nine people, including the captain, died in the inferno, while seven crew members survived.
Divers also recovered the ship's anchor and part of the rudder, along with bottles, ointment jars, and a complete women's sewing kit.
Mr. Goodwin said the project had its genesis when the Corps of Engineers and Port Administration decided to deepen the Chesapeake Bay shipping channel.
A remote-sensing survey of the bottom detected a number of shipwrecks. The wreck of the Columbus was well-documented at the time, so once the survey showed the remains of cross-head engine, officials knew they'd found what they were looking for and the recovery went ahead, Mr. Goodwin said.
Even though the cross-head engine was replaced within 25 years by a more efficient design, it remained a missing piece in the history of engine development.
"It's like trying to understand the engineering of modern automobiles without having known how the Model A or Model T were built," Mr. Goodwin said. "This gives us that early background."