USS Monitor’s Turret Has Surprises For Conservators
NEWPORT NEWS, Va. – Great progress has been made with the conservation of the USS Monitor’s turret and engine over the past year, according to David Krop, Monitor Collection Conservation Project Manager for The Mariners’ Museum. The view of the Monitor’s turret “is spectacular,” Krop said. From Monday through Friday, for most of July and August, the water tank holding the turret has been drained to allow the conservators full access. A sprinkler system has kept the iron surfaces wet to prevent corrosion. Museum visitors have been able to watch the work from observation decks overlooking the conservation lab. The museum’s conservation staff has been busy removing the last bits of concretion from the interior and exterior of the ironclad’s revolving armored 140-ton gun turret, making some new discoveries along the way, according to Krop. “We recovered the remains of a bone-handle knife, an adjustable wrench, a decorative brass piece, glass fragments, rope, leather and other small items from the interior of the turret,” Krop said. The three sight holes are now visible in the turret, evenly spaced at the 6, 10 and 2 o’clock positions. Krop said they allowed turret crewmen to see outside without opening the hatches in the roof and exposing themselves to hostile fire. The dents left by Confederate cannon fire, and recorded in photos of the ship taken in July 1862, are fully visible as well. Conservators are carefully documenting the stanchions that held the Monitor’s canopy over the turret. Krop said the ones still attached are all bent to the same side, providing clues about the impact of the upside-down turret on the sea floor when the ship sank. “We’re learning so much,” Krop said. “Yes, we’ve had the turret here since 2002. Yes, a lot of archival material survived from historical accounts and contemporary reports. But we’re still learning something new every day we go inside of the turret tank.” An extensive briefing on the conservation of the Monitor’s engine was given by Eric Nordgren, senior conservator at The Mariners’ Museum, and assistant conservator Will Hoffman, at the museum’s annual Battle of Hampton Roads Weekend in March. “Some of the most exciting work on the Monitor’s engine has occurred recently,” according to Nordgren. “Eventually, we’ll be able to take it apart.” The engine is being de-concreted of accumulated marine growth and corrosion and systematically disassembled. The Monitor’s main engine was recovered in 2001, Nordgren said. Related objects brought up include the engine condenser, Worthington pump and ventilation engines. The Monitor’s engine was a vibrating side-lever steam engine, designed by John Ericsson, the ship’s Swedish-American naval architect. It had two cylinders and produced approximately 400 horsepower, giving the ship a top speed of 6-8 knots. “For its time, it was quite advanced,” according to Nordgren. Today, though, we would see it as “slow and lumbering.” The conservators are helped in their task by surviving documentation. “We have a lot of the original plans and blueprints of the engine and other parts of the Monitor as well,” Nordgren explained. The conservation work includes removing nearly 150 years of marine concretion as well as salt from seawater that is corrosive to the iron that makes up much of the ship and its components. To best treat some recovered objects which are made of different materials, like the gun carriages that are iron and wood, they must be disassembled, Hoffman said. The chemicals and other techniques used to treat the objects can vary by type of material. Something like the engine, which was meant to be taken apart when serviced, is particularly amenable to disassembly, Nordgren said. This is in contrast to the turret, which, although comprised of 192 one-inch-thick iron plates, was not meant to be taken apart after it was built. The Monitor’s main engine sits in 30,000 gallons of fresh water. Hoffman said so far they have removed four tons of concretion from the engine. One of the interesting aspects of de-concreting large objects, like the engine, is that sometimes smaller objects are discovered inside the concretion. For instance, a small oil can was found in some of the concretion taken from the main engine. As an aid to understanding what is inside the engine, they plan to use a camera attached to a cable, similar to what a plumber uses to look inside clogged pipes, Hoffman said. The ongoing work is carefully documented, according to Nordgren. Methods include digital photos taken from different angles, drawings and 3-D laser scanning. The latter produces data that can be put into computer-aided design (CAD) software for 3-D modeling. The target for completing conservation of all the objects recovered from the Monitor is 2029. Nordgren said, “We hope we can beat that by a good number of years.” The iconic Union ship fought the CSS Virginia in the first clash between ironclads at the Battle of Hampton Roads on March 9, 1862. She sank off Cape Hatteras, N.C., on New Year’s Eve in 1862 while being towed to Port Royal, S.C., to participate in Union operations against the Confederate stronghold of Charleston, S.C. The wreck of the Monitor was discovered 16 miles off Cape Hatteras in 230 feet of water in 1973. In 1975, the site was protected by being designated by Congress as the nation’s first National Marine Sanctuary and is managed by the National Oceanic and Atmospheric Administration (NOAA). The Mariners’ Museum was designated in 1987 as the repository of artifacts recovered from the Monitor. NOAA and the U.S. Navy determined that the entire ship could not be recovered intact, and so selected artifacts were removed for conservation and future public display, including the revolving gun turret in 2002. Since the opening of the USS Monitor Center at The Mariners’ Museum in 2007, the turret, engine and other large artifacts have been moved from outdoor conservation tanks indoors to the state-of-the-art Batten Conservation Laboratory Complex. Information about the latest conservation developments are available through the USS Monitor Center Blog and live conservation Webcams at www.marinersmuseum.org/blogs/ussmonitorcenter/.
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