In an article yesterday on the steamboat Columbus, the builder of the ship's engine was misidentified. His name is Charles Reeder.
The Sun regrets the error.
Archaeologists say they have found a missing link in the evolution of American steamship technology -- the massive iron-and-copper engine from the side-wheeler Columbus, which caught fire and sank in the Chesapeake Bay almost 142 years ago.
The charred timbers of the 220-foot shipwreck cradle what may be the only surviving specimen of a crosshead engine, said Paul Hundley, underwater archaeologist with the Maryland Historical Trust. The crosshead was the earliest steam power plant used extensively by bay ships.
The Army Corps of Engineers, hoping to salvage the historic machine and clear the shipping channel of a potential hazard, plans to send divers to recover the engine by the end of this year.
"In terms of industrial history, this is a very significant find," said Donald G. Shomette, chief of the graphics section of the Library of Congress and an expert on Chesapeake Bay history.
The Columbus, built in Baltimore, began hauling freight and passengers up and down the bay in 1828, just 15 years after the launch of the Chesapeake, the bay's first steamer. It was only 21 years after Robert Fulton launched America's first commercially successful steamboat, the Clermont, on the Hudson River.
The crosshead design was simple but inefficient and unreliable. By the mid-1800s, Chesapeake steamships were being built with a more advanced engine style called the "walking beam."
"This early period of steamship construction is a real experimental time," Mr. Hundley said, a time when designers and builders were learning to build boilers that didn't blow up and machinery that didn't break down.
Construction of the crosshead engine, he said, "is linked directly to the development of Baltimore as an industrial and maritime center in the United States."
The shipwreck's location has been charted since at least the late 1970s, state officials said. But like the vast majority of the estimated 4,500 shipwrecks scattered along the bottom of the bay, the identity of the vessel was unknown.
After the Army Corps of Engineers deepened a channel to 60 feet next to the Columbus in 1990, the corps decided that its tangle of engine parts posed a hazard to deep-draft ships.
As required by federal law, the corps ordered an archaeological study as a prelude to removal.
R. Christopher Goodwin & Associates of Frederick sent divers to the site in March 1991. After another a year of archival research and other detective work, researchers concluded this spring that the wreck was probably the Columbus.
Both the state and the corps asked that the precise position be withheld to ensure that relic-hunters do not haul off parts of the engine before recovery begins.
According to contemporary accounts in The Baltimore Sun, the Columbus' copper-sheathed hull was plowing south through the bay waters around 3 a.m. one Wednesday in the fall of 1850 when crew members noticed that the wood-fired furnace was refusing to draw smoke up its chimney.
A few minutes later, what witnesses called a "broad sheet of flame" shot out of the mouth of the furnace, killing deckhand Henry Estep and setting the engine room's woodpile afire, The Sun reported.
The fire spread quickly through the timber superstructure, and seven crew members scrambled into one of the ship's two lifeboats.
But Capt. John Hollingshead refused to join them, turning and disappearing into the smoke. Crew members said later that they thought he went in search of a missing 9-year-old boy, the son of 1st Mate Littleton S. Godwin.
Survivors watched the Columbus drift off, still burning, and disappear in the morning mist. Captain Hollingshead, 1st Mate Godwin, his son and six others either died in the fire or drowned. The value of the ship and cargo was estimated at $35,000.
Executives with the Powhatan Steamboat Co. later speculated that a spark arrester in the smokestack "became clogged with cinders, and reversed the draft, as has been the case in other steam vessels," The Sun reported.
The Columbus' crosshead engine, built by Charles Breeder of Baltimore, consisted of a steam-powered piston more than 4 feet in diameter moving inside an 18-foot-high iron cylinder. The piston pushed an overhead T-shaped iron-and-wood bar -- the crosshead -- set in vertical tracks mounted on an A-frame structure.
In the later, walking beam design, the crosshead was replaced by a see-saw structure that more efficiently transferred power from the piston to the paddle wheels.
Corps officials are making plans to salvage the engine, which lies in about 50 feet of water, said Mimi Woods, an archaeologist with the corps' Baltimore district. The iron parts have been soaking in salt water for almost a century and a half and might crumble if exposed to air, archaeologists said.
Ms. Woods said the engine is to be shipped to the International Artifact Conservation and Research Laboratory Inc. of New Orleans, where its iron will be painstakingly cleaned and then stabilized in a process similar to electroplating.
The work is expected to take two to three years.
Later, the corps intends to turn over the engine to the Maryland Historical Trust. Mr. Hundley said the engine may become an exhibit at the new Christopher Columbus Center planned for the Inner Harbor.
The corps and the Maryland Port Administration are splitting the $348,000 cost of recovering and preserving the engine, Ms. Woods said.