Conservators used two 20-ton hoists and an ingenious doughnut-shaped turning cradle Wednesday to right one of the massive upside-down cannon recovered in 2000 from the wreck of the USS Monitor.
The 13-foot-long Dahlgren gun, which weighs about 17,000 pounds, helped the famous Civil War vessel make naval history when it squared off with the CSS Virginia - also known as the Merrimack - on March 9, 1862, in the first battle between ironclad ships.
But not since the Monitor sank and landed upside down off Cape Hatteras, N.C., at the end of 1862 has either of its two guns laid upright, enabling onlookers to inspect the commemorative engraving chiseled into the top of the barrel after the landmark engagement.
"It's nice to see it over on the right side," said Mariners' artifact handler Gary Paden, who helped design the turning rig. "It's been a good long while."
Carefully hoisted from the ship's pioneering gun turret in late 2004, both the starboard and port cannons were transferred to separate 8,000-gallon treatment tanks inside the cavernous USS Monitor Center conservation lab. There the huge guns have soaked for nearly three years in a sodium hydroxide bath designed to draw potentially catastrophic deposits of chloride compounds from their vulnerable cast-iron barrels.
Three months ago, the conservation team rigged the bores of the guns with a low-ampere electrical current that will accelerate the pace of the treatment process. But Wednesday's ponderous juggling act will enable them to wrap the exterior of the barrel with a stainless-steel anode mesh, increasing the effectiveness and the speed of the electrolytic regime still further.
The careful lift and turn also enabled the conservators to expose two sections of the cannon that had previously escaped treatment because of the wooden cribbing that covers part of the bottom surface.
"This is really going to help speed things up," Mariners' conservator Dave Krop said. "But the barrel is nearly 18 inches thick at the breech. So the whole process is still going to take four or five years."
The cannon and its mate will have to be turned several more times during treatment - making Wednesday's two-hour-long maneuver the first in a long series of industrial-sized tests for the Mariners' conservation team.
But once they lifted the giant artifact from its tank, lowered it into the bottom half of the doughnut-shaped cradle and bolted the top half down, they carried out the actual turning in less than 15 seconds, rolling the cannon and its supporting cage by hand across the lab's thick concrete floor.
"The idea was to turn it but not touch it," said Paden, explaining how welders from Northrop Grumman's shipyard Apprentice School fabricated the two steel wheels supporting each end of the gun.
"Once it's in this rig, two guys can roll it over."
The team drew much of its confidence from the original lift of late 2004, when worries about the condition of an artifact that had been tested in battle, battered by a catastrophic shipwreck and subjected to nearly 142 years of saltwater corrosion led many observers to hold their breaths and cross their fingers.
But the conservators still showed plenty of excitement when they completed the unexpectedly trouble-free turn just before 11 a.m. Wednesday, then removed the top half of the turning rig to reveal the commemorative Civil War engraving on the barrel.
Executed by workmen at the Washington Navy Yard a few months after the ship's epic 1862 battle in Hampton Roads, the simple two-line inscription honors the Monitor's designer - Swedish-American naval architect John Ericsson - as well as the historic clash with the Virginia. A similar engraving on the other gun honors Monitor Capt. John Worden.
Because of the tumble that took place during the wreck, however, neither of the inscriptions was clearly visible until the Ericsson gun was turned right side up. So well-preserved were the names that appeared when the rig was removed that Monitor National Marine Sanctuary historian Jeff Johnston leaned over and - only partly in jest - kissed the historic metal.
"We are pleasantly surprised by the state of preservation," Krop said, smiling as he studied the cannon's condition.
"The corrosion product you see may look pretty gnarly. But as it sloughs off during treatment, it's looking more and more like the original metal. So all the dents and scars you see come from its time aboard the Monitor."Copyright © 2015, Los Angeles Times