Cannons and cribs: Archaeologists provide details on Revolutionary War weapons and Confederate water obstructions found in Savannah River

Planks at the bottom of this obstruction are shown in dark area (USACE)

Over the years, underwater archaeologists have found that amid all the junk littering the bottom of the Savannah River is a trove of treasure.

Such was the case in 2021, when they spotted 15 Revolutionary War-era cannons and explored obstructions placed in the river 85 years later during the Civil War.

Contractors working for the US Army Corps of Engineers surveyed and dived two Confederate “cribs” -- or tall wooden boxes filled mostly with brick – that discouraged the approach of Union ships to the port city. Forces towed the wooden obstructions, believed to be 40 feet by 40 feet, and put them in place near Fort Jackson and the ironclad CSS Georgia, a floating battery that was part of the Savannah River defenses.

Archaeologists last month provided details of the Revolutionary War and Civil War artifacts during a public event at the Savannah History Museum. Three cannons were recovered last year, while the other 12 were pulled up in January.

The Army Corps’ Savannah district funded the hard-hat dives as part of the busy Georgia port’s channel deepening.

About a half dozen severely degraded cribs are on the South Carolina side of the river. Crews focused on what are called cribs C and D.

Commonwealth Heritage Group divers found some planks used to build Crib C.

“On top of the planks it was tons of bricks that we dug through, and then underneath the planks it was sterile sand and Miocene clay, which is the base of the river,” said archaeologist Stephen James. “That basically told us we were at the bottom of the crib.”

They found an intact corner at Crib D. While C won’t be impacted by the deepening, the remnants of D were documented and then largely destroyed by dredging, James said. “There is very little of the cribs left.”

The Confederacy used a wide array of weapons and obstructions to deter advances on Savannah from the sea. Besides forts and warships, wooden cribs, pile dams, torpedoes (mines), snags, logs and shipwrecks were employed.

Divers located an intact corner on this obstruction (USACE)

Time and dredging have taken their toll on the cribs over the past 160 years. But that’s not all.

After the Civil War ended in 1865, the city wanted to reopen the port and it hired salvage companies to remove river obstructions, including the cribs and pieces of the scuttled CSS Georgia. 

“They had their own demolition. Surprisingly, they had divers back then, had pretty heavy-duty machinery to pull that stuff down,” said Will Wilson of Commonwealth Heritage Group. Of course, not all of the objects were removed or recovered in the 19th century.

Topographic view of four cribs from survey. Dredged channel is in blue (USACE)

The Corps is in charge of the ongoing deepening of the Savannah harbor and the dives are part of an investigation of historical resources that have been or could be affected.

Officials referred to period maps and descriptions from Union Corps of Engineers Capt. William Ludlow and a Capt. Boutelle for information on the cribs.

The CSS Georgia is on the National Register of Historic Places and the cribs are eligible for inclusion, officials say.

While in poor shape, four Civil War river obstructions -- or cribs -- in Savannah remain intact in places, Corps officials say

Design of cribs placed in the Savannah River -- click to enlarge (National Archives)

Divers in Savannah, Ga., recently spotted intact portions of two cribs – or tall wooden boxes filled mostly with brick – that were dropped into the river during the Civil War to discourage the approach of Union ships to the port city.

Confederate forces towed the wooden obstructions, believed to be about 40 feet by 40 feet, and put them in place near Fort Jackson and the ironclad CSS Georgia, a floating battery that was part of the Savannah River defenses.

“They were severely degraded. They were not in great shape,” U.S. Army Corps of Engineers Savannah District archaeologist Andrea Farmer said of the condition of what are termed Crib C and Crib D. But a few portions, including the corner of one crib, had remained mostly intact.

Contract divers using sonar last fall located four of the cribs on the South Carolina side of the river. Cribs A and B were previously explored and the dives in November and December concentrated mostly on C and D, Farmer told the Picket earlier this month.

The Corps is in charge of the ongoing deepening of the Savannah harbor and the dives are part of an investigation of historical resources that have been or could be affected. The Corps recently concluded the recovery of artifacts from the CSS Georgia, which was scuttled by its crew in December 1864 shortly before Federal forces took Savannah and was in the current shipping channel.

While tourists to the popular coastal destination gaze upon the supertankers coming from or to the Atlantic Ocean, they likely have no idea what lies beneath the surface: Remnants of vessels, pieces of Native American pottery that washed down stream, and other items deposited over the centuries.

View of cribs from multibeam survey. Dredged channel is in blue (USACE)

Divers in the past year have located numerous cannons in the river in this area, likely from the Revolutionary War era. They are trying to determine how they came to be in the water.

The Confederacy used a wide array of weapons and obstructions to deter advances on Savannah from the sea. Besides forts and warships, wooden cribs, pile dams, torpedoes (mines), snags, logs and shipwrecks were employed.

Unlike the cannons, the four cribs will be left in place. They are not expected to be directly affected by future channel deepening because they are on the northern edge of the project, Farmer said.

Corps officials referred to period maps and descriptions from Union Corps of Engineers Capt. William Ludlow and Capt. Charles Boutelle for information on the cribs. Boutelle, working for the U.S. Coast Survey, made a December 1865 survey of obstructions in the Savannah River.

Topographic view of four cribs from survey. Dredged channel is in blue (USACE)

“It is assumed, based on the lack wood cribbing left, that only the base or lowest portion of the cribs remain, and the extant portions differ by crib,” Farmer wrote in an email. “It looks like normal crib construction. There is nothing unusual or special about the cribs.”

She said the cribs initially would have been at or near the surface but years of deterioration have reduced them mostly to debris a few feet about the river bottom.

“Crib A may be the most well preserved, as it seems to have the greatest amount of material based on the current height of the obstruction. Cribs C and D contain more material than Crib B, both in terms of extant structure and rubble/brick fill based on the areas that have been excavated.”

The Corps said it hopes to provide photos of the dives soon.

Examination of harbor from the city to Elba Island (USACE)

It's a wrap: U.S. Army Corps of Engineers officially ends recovery of ironclad CSS Georgia's artifacts in Savannah

Exultant workers lift a piece of the CSS Georgia in November 2013 (USACE)

The recovery of the CSS Georgia, a Confederate ironclad gunboat that saw no action but left thousands of fascinating artifacts in its wake, has been officially completed.

The U.S. Army Corps of Engineers in Savannah, Ga., recently announced the end to its archaeological data recovery.

“We were able to recover much of the vessel from 2015 to 2017 and have been working to conserve the historical artifacts we found since then,” said Andrea Farmer, Savannah District archaeologist, in a news release. “Removing the Georgia from the river was important, not only for preserving the archaeological record, but also to ensure its safety during the district’s Savannah Harbor Expansion Project.”

Most of the ironclad’s wreckage was removed a few years back as part of the Corps’ deepening of the Savannah River to make room for larger tankers. Thousands of artifacts have since undergone treatment at Texas A&M University.

Conserved artifacts have been transported over the years to Naval History and Heritage Command (NHHC) in Washington, D.C., where they are being stored and curated for possible museum display. (At left, a Dahlgren hauled up in 2015).

Post-Civil War salvage operations, dredging damage in more recent times and a dearth of historical records make it impossible to come up with firm conclusions on many aspects of the scuttled CSS Georgia, a floating battery that defended the entrance to Savannah’s port during the Civil War.

Archaeologists and historians pored over data that resulted from 2015 and 2017 recovery operations near Fort Jackson and from earlier dives. While they learned much about the underpowered ironclad, a report issued last year said the derisively nicknamed “Mud Tub” will continue to hold mysteries because some vital parts are missing or so disarticulated that it is impossible to come up with a complete picture of the vessel’s design and operation.

There were, however, some critical findings.

“The most specific information concerns the dimensions and construction details of the armored casemate with evidence indicating it was approximately 120 feet long by 44 feet wide,” Panamerican Consultants wrote in a report to the Corps.

Illustration of CSS Georgia near Fort Jackson (USACE)

The sheer number and array of artifacts -- which includes interlocking railroad iron used to for armor -- found in the river made up a large part of the massive report.

This month’s news release from the Corps said the project, which involved contractors and U.S. Navy divers, recovered more than 30,000 artifacts, including 241 pieces of ordnance, five cannons and two large casemate sections. The latter were documented and left in the water.

“Restoring historical artifacts, especially ones found underwater, is a lengthy and expensive process,” Farmer said in the news release. “The artifacts that were not chosen for restoration were placed in containers, transported upriver, and reburied where they will be safe and out of the way for many years to come.”

About 1,600 non-conserved artifacts were shipped to Savannah from Texas and reburied in a secure location in December, ending project data recovery and mitigation activities, said spokesperson Nathan Wilkes of the Corps' Savannah District. “These artifacts were individually inventoried, visually inspected and assessed as nonsignificant at Texas A&M University’s Conservation Research Lab.”

Jim Jobling, lab manager at Texas A&M's Conservation Research Laboratory, told the Picket in an email that about 18,500 conserved artifacts have been sent to the NHCC. 

Jim Jobling with a 3D model of an artifact (Picket photo)

Jobling was on barges used in the CSS Georgia recovery and witnessed artifacts being brought up by divers or by machinery and helped catalog them. "It was a good project, with a lot of good people putting in many hours of hard work -- over and above the call of duty."

Locally built in 1862, the CSS Georgia was an integral element of the Confederate defenses that protected Savannah until the Union Army captured the city. In December 1864, the CSS Georgia was scuttled by Confederate forces to prevent it from falling into enemy hands.

Navy officials would like to see many of the items displayed but no museums have committed to such a project, given the expense and required environmental controls to protect the items.

Lt. Anthony Ivester, public affairs officer for the Naval History and Heritage Command, confirmed it has received all conserved artifacts from Texas A&M.

CSS Georgia: As artifact conservation continues, public will soon be able to read detailed report on this unique Savannah ironclad

Valve assembly has dozens of parts (U.S. Army Corps of Engineers)

Historians and archaeologists don’t know whether the builders of the CSS Georgia, an ironclad that guarded the Savannah River in the city of same name, worked from blueprints. None have been found in the years since the Civil War.

But that doesn’t mean there’s no way to describe the Confederate vessel’s propulsion, the angle and construction of protective casemate or to estimate the vessel’s width and length.

Dahlgren recovered in Sept. 2015 (USACE)

Between 2013 and 2017, machinery and divers working at the CSS Georgia’s resting place a few miles from downtown Savannah recovered thousands of artifacts. The project was necessary before a major harbor deepening project began: The boat’s remains lie in the main shipping channel.

An upcoming report from the Savannah office of the U.S. Army Corps of Engineers will provide a general analysis about the artifacts and an overview of the project. The finds included nearly a half dozen cannon, a propeller and large pieces of the casemate, fashioned from – of all things – interlocking sections of railroad iron.

Officials believe the artifacts will answer a lot of questions about the vessel.

Divers, working in visibility that one likened to chocolate pudding, slipped beneath the surface of the Savannah River and down to the disarticulated remains of the vessel that was scuttled by its crew in December 1864 when the Yankees arrived at the seaport’s front door.

The Corps recovered a significant portion of the CSS Georgia, which served as what’s called a floating battery. In the years since, items large and small have been cleaned at Texas A&M University's Conservation Research Laboratory. (The lab's operations have been affected by the recent coronavirus pandemic.)

“Conservation continues,” says Julie Morgan, district archaeologist for the Corps. “The conservation process is slowing down considerably as the artifacts that are now in conservation are more complex -- they have more individual components and are comprised of multiple metals -- so the number of artifacts finishing completion is slowing.”

Morgan and experts brought in for the project have been especially fascinated by the ironclad’s propulsion system and engines. It’s known the one-off CSS Georgia – built not far from where it sank -- was underpowered.

Locals derisively called it the “Mud Tub” because it was unable to leave the city and attack Federal ships that had bottled up Savannah’s river entrance. But they may have gotten something better. The CSS Georgia became a strong element of extensive water defenses. It never fired upon the enemy, because the enemy decided to probe vulnerabilities elsewhere.

Julie Morgan has researched the CSS Georgia for years (USACE)

Morgan provided two examples to the Picket of the complexity of some items.

The Conservation Research Laboratory had to separate seven sections of a valve assembly. They removed rubber gaskets and about 52 nuts and bolts.

And two engine cylinders, each about 48 inches long, must be carefully moved with a forklift. And conservators must precisely cut to reach the cylinders’ interior.

It’s important to note the wreck site of the CSS Georgia was not undisturbed. 

Dredging hits and scars, along with salvage attempts not long after the Civil War, made the site a jumble of rotting wood, chunks of casemate and loose rail and machinery.

Still, the trove of artifacts, have an important story to tell of innovation when builders had access to less-than-ideal armor and technology.

The CSS Georgia belongs to the U.S. Navy, under the auspices of the Naval History and Heritage Command.

Carefully packed shipment or ordnance (USACE)

“To date, the conservation lab has made two shipments of artifacts to the Naval History and Heritage Command,” said Morgan. “Packing the artifacts is very time consuming as everything must be wrapped and packed in archival quality materials.”

The items are being stored at the Washington Navy Yard, where officials are cataloging and storing them in hopes that a museum will eventually come forward with a plan to exhibit the artifacts and tell the CSS Georgia’s story.

The public will have an opportunity to read all about it in Morgan’s report.

“The Corps is currently reviewing the revised draft and the final version will be printed in late April,” she said. “Once that document has been accepted by the government it will be made available to the public through the district’s website.”