Conserving the Cairo: Work being done to preserve historic ship at Vicksburg National Military Park
Published 2:53 pm Thursday, November 7, 2024
In 1862, while on an expedition on the Yazoo River, the USS Cairo struck a mine and was sunk. The City Class ironclad gunboat would rest there for more than 100 years before it was raised from the mud in 1964 by state and local authorities.
In its current form, supported by a wooden and concrete structure and covered by a large canopy, the vessel sits beside the Vicksburg National Cemetery inside the Vicksburg National Military Park.
The Cairo is now undergoing an intense conservation effort by artifact preservation specialists Terra Mare Conservation. The group was founded by conservators Claudia Chemello and Paul Mardikian. The third member of the team is Casey Heffron, a graduate student studying maritime archaeology.
“We treat materials from wet and dry environments, but we also work on really modern materials, too. One of our great projects was the F1 engines that sent man to the moon,” Chemello said
In 2013, the owner of Amazon, Jeff Bezos, had engines from the first stage of the Apollo 11 launch vehicle recovered from the bottom of the ocean. Terra Mare worked on their preservation.
“We were both, Paul and I, trained in archaeological conservation, which is another sort of specialty of conservation,” Chemello said. “So you’re talking about artifacts that have come out of very different contexts, land or sea.”
Terra Mare’s name is Italian for “Land Sea”.
A major portion of the work being done on the Cairo is cleaning. So far, Terra Mare has removed more than 600 pounds of debris from different areas of the vessel, which built up over the ten years since the last deep cleaning was done.
“Just accumulated dirt, pollen, dead insects, cobwebs, tiny fragments of wood, just everything,” Chemello said. All of these things inevitably gather on the surfaces of the Cairo simply because it is outside.
The work is done with specialty vacuums with HEPA filters for safety and variable power settings to prevent damaging the remains of the ship. Cobwebs are especially difficult to remove without the correct attachment.
While cleaning has taken up much of the team’s time, they will also be repairing some wooden parts of the ship that have shifted over the years and need to be set back into place.
“It is astounding to have this much (wood) surviving. I can say now, having crawled all over the ship, It’s extremely fragile. It’s a lot more fragile than I think anyone believes, to look at it,” Chemello said. “But there are some areas that, If you were to touch them, they would be as light as a piece of cork. It’s hard to understand that because you’re looking at a large timber, but it’s got no structural integrity.”
Part of the reason for that lack of structural integrity is because the Cairo, once raised, was left to dry very quickly out in the open, causing the wooden parts to shrink significantly.
Chemello pointed out that conservation work practices have changed quite a bit since the Cairo was first pulled from the bottom of the Yazoo River in 1964. If the ship was to be raised today, it would likely be immediately transferred to a climate-controlled facility specially built for the project to prevent further decay.
Being outdoors, what is left of the original wooden structure is constantly absorbing moisture and drying out again. Chemello said the shade canopy has helped, but the wooden pieces are still at the mercy of the elements.
“This is like a giant sponge,” Chemello said. “So if you have moisture, you have insects, you have biological deterioration.”
There is active fungal decay.
“You’ve got extreme loss,” she said. “There’s a way to arrest it, and that’s putting it indoors.”
Chemello’s team is making the recommendation to have the Cairo placed indoors; however, there are no immediate plans to do so.
As for the continual build-up of debris, the Park Service is planning to have more regular cleanings of the ship.
Brendan Wilson is the program manager for Visitor Experience and Outreach at the Military Park.
“All that just builds up over time. That’s why you need this regular, cyclical ‘getting in there,’” Wilson said. “The Park Service staff had been cleaning before, but also as time went on, we needed to be able to bring in professional conservators to really make sure we’re doing this (correctly).”
Only four ironclads from the Civil War still exist. One thing that makes the Cairo unique is that it provides a snapshot of life aboard the vessel, according to Wilson.
The Cairo sank in about 12 minutes, meaning sailors had little time to remove items from the boat before abandoning the ship. As a result, a wealth of artifacts were discovered inside the wreck, many of which are on display at the museum that sits next to the ship.
“We’re talking leather shoes, mess kits, and rubber sutures, all kinds of things,” Wilson said. “So that gives us a capture of a moment in time, of what life was like for the sailors who served on this ship.”
Wilson added that, ironically, the ship was preserved due to having been sunk. If she had survived the war, she would have almost certainly been scrapped.
According to Chemello, the Cairo’s environment while submerged was the reason so much material exists today. The ship sunk in fresh water, and much of it was buried under mud.
“So as conservators, we always talk about the environment and the materials, and those two things together dictate what level of preservation you’re going to have,” she said. “If this had been in the ocean, you would have none of this. The shipworms would have eaten the wood.”
A body of water with higher salinity would have also degraded the metal components.
“There is corrosion (on the metal). We can see it, but it’s not to the advanced level you would get in the ocean. It would be extreme,” Chemello said. “So all the large machinery, none of that would have survived.”
Massive boilers, guns, and plate armor are just some of the metal portions of the wreck.
Mardikian was working on cleaning the large iron frame of the paddle wheel.
“It’s a monster because there’s a lot of surface area. And it’s quite difficult to access. So what we have to do is to be harnessed and be absolutely safe,” Mardikian said. “This is rule number one on our project, and I have to say that we’ve not had a problem other than a wasp sting.”
Wilson said that the Cairo’s weather canopy and the adjoining museum have also been getting updates.
“So the work here is part of the start of more of a regular cyclical maintenance and conservation schedule. Also being able to not only work on the conservation of the boat itself but a refreshing of the whole visitor experience here,” Wilson said. “Last year we cleaned the canopy and repainted all of the supports for it. We also refreshed some things in the bookstore, put in a new desk for the contact station, new fixtures for the bookstore, and we’re working on putting some new HVAC elements in.”
Chemello said she is expecting the team to finish around the end of November, meaning the whole project will take about three months. The cost of the work is about $350,000. The Park Service is also hoping to fund a 5-year annual cyclic cleaning project that will cost around $45,000 per year.
Some portions of the USS Cairo may be off-limits during the conservation process.