Workers repairing the 1854 sloop of war Constellation have uncovered significant rot in the ship's hull.
The damage, attributed to rainwater seeping into the hull from the gun ports, is expected to lengthen the ship's time in dry dock at the Sparrows Point Shipyard by 10 to 14 days and add about $70,000 to the $500,000 repair bill.
The water intrusion has been stopped, and some of the rotted wood has been cut out and replaced. But Chris Rowsom, executive director of Historic Ships in Baltimore, said the Constellation will need more extensive repairs in two to three years that could take it away from the Inner Harbor for up to six months.
"It's not like it was in 1996. The ship was literally falling apart at that time," he said. "This is definitely manageable. It is a large project; I won't kid anybody. But it's definitely manageable."
All of the damage discovered so far has been limited to the modern laminated hull constructed during restoration work in the late 1990s, he said.
"All the ship's original, historic fabric is fine. The frames, the hull planking, there's no problem in those areas," he said. "She is very, very strong. But we do need to take care of these problems."
The Constellation entered the graving dock at Sparrows Point on Jan. 31 for a month of hull cleaning, painting and resealing. The World War II submarine Torsk was dry-docked at the same time for more extensive repairs.
During inspections, workers found evidence of rot near the stern on the wooden warship's right side.
"We started digging, and the hole got bigger and bigger," Rowsom recalled. Eventually, they followed the rotted wood down 10 feet below the waterline, eventually expanding to an irregular area 40 feet long by up to 8 feet wide. "Finally, we had to say, 'We've got to find a stopping point here.'"
At first, they suspected shipworms — bivalves that burrow into the hulls of wooden ships and eat the wood. But it has turned out to be simple rot, caused by fungus and invaded by marine bloodworms. And it was not a complete surprise.
Historic Ships discovered several years ago that fresh water was seeping down from the gun port sills into the top of the laminated hull. The ship's caretakers have spent the past two years cutting out what rot they could find, reshaping the sills so they drained properly and capping them with copper to stop the water intrusion. But the extent of the damage was unexpected.
"We had no idea going into dry dock we were going to find what we found," Rowsom said.
In addition to the hull rot near the stern, the inspections also found rot around the waterline where small boats have bumped the ship, nicked the hull and broken the watertight epoxy seal on the surface.
Maryland weather blog: Frank Roylance on meteorology
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