Calm seas and a cooperative current favored Monitor Expedition 2002 last week, enabling Navy divers to lower a 29-ton, eight-legged lifting frame through the depths and place it over the historic gun turret of the USS Monitor.
But a hidden fragment of oak and armor plating caught one of the massive legs as it sank into the sand, leaving the divers and their partners from the Monitor National Marine Sanctuary stunned as the frame skewed off course, scraping down the side of the 140-year-old Civil War turret.
No serious damage was found after the sediment cleared, said underwater archaeologist John Broadwater, head of the Newport News-based team of scientists that is guiding the Navy divers. But the off-center, uneven landing of the spider-like rig left the $7.1 million expedition with a perplexing engineering problem some 240 feet below the surface - plus a scary reminder of the wreck's vulnerability.
"It went a whole lot better than my worst nightmares have been," Broadwater said late Wednesday night, as the divers and National Oceanic and Atmospheric Administration scientists met to devise a solution.
"But getting out of this is going to be slow - and we don't want to make it worse."
The last-second mishap came after more than three weeks of meticulous preparation, beginning with the removal of a 42-foot-long section of armor belt that had rested on top of the turret.
Cutting the giant, 5-foot-tall band of iron plate and wood away from the rest of the wreck, the divers then went to work on the turret itself, clearing the coal- and coral-filled interior to expose the Monitor's pair of 15,750-pound Dahlgren guns. They also excavated a 5- to 6-foot-wide trench around the outside of the turret, searching for any debris that might catch the lifting frame's legs.
Suspended over the surface by a 500-ton capacity crane, the frame entered the water not long after 6:30 a.m., with two Navy divers leaping in afterward to raise the fixture's hinged, hydraulically adjusted legs.
Then the master diver and diving warrant officer in charge guided it down, relaying instructions to the crane operator as they watched the descent through a quartet of flickering video monitors.
Bobbing and twisting slightly from the roll of the barge, the frame stopped just a few feet above the turret, where two other divers helped to steady it through a pair of tending lines.
Then the expedition seemed to hold its breath, gauging the lazy swells and the unpredictable currents in search of a scant, 30-second-long lull.
"We're coming down easy. Coming down easy. Coming down easy," Master Diver Jim Mariano said, as he and Diving Warrant Officer Rick Cavey mulled over the right moment to make the final drop.
Then, "Down! Down! Down!" they ordered sharply, peering intently into the screens as the frame fell the final 10 feet, disappearing with the turret into a billowing cloud of stirred-up sediment.
Nearly a minute passed before the divers could see well enough to make their reports. And as the off-kilter profile of the frame emerged from the haze, Cmdr. Bobbie Scholley, the Navy officer in charge of the expedition, grimaced with disappointment.
Still, the scrapes to the turret appeared to have damaged only the thick, shell-filled layers of marine encrustation - not the iron plates of the turret itself. Within minutes, the divers were back at work, intent on edging the heavy frame into position an inch at a time through a labor-intensive process of winching, lifting and undermining the legs.
Not long afterward, they discovered the hidden timber and iron plate that had thrown the fixture off course. Two other deeply buried fragments would slow them later in the week as they worked round the clock to nudge the frame into place.
"It's been slow and steady here," Scholley said Friday, reporting that her divers had coaxed the massive fixture nearly 12 more inches across the ocean floor. Less than a half-foot remained from their original target, and the frame had started to level out smartly, too.
"I wish that it had gone straight down perfect to begin with," she said, still stinging from the close call.
"But it's starting to really look good."
Mark St. John Erickson can be reached at 247-4783 or by e-mail at email@example.comCopyright © 2015, Los Angeles Times