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.

Archaeologists find even more old cannons in the Savannah River. They hope to solve the mystery of their origin and history

Will Wilson and Jeffrey Pardee during Oct. 12 dive (USACE Savannah)

The Savannah River is proving to be a graveyard for military cannons.

Following the February discovery in Savannah, Ga., of three artillery pieces that may date to the mid-1700s, archaeologists last month came across more artifacts.

“We were able to confirm two additional cannon that we knew about before. We found what we believe to be another cannon -- a very small cannon. We found what may be the muzzle of another cannon,” Will Wilson, an archaeologist with Commonwealth Heritage Group, said in a video posted last week by the Savannah district of the US Army Corps of Engineers.

Corps district spokesman Billy Birdwell expects the artifacts recovery near Old Fort Jackson to conclude in the next couple weeks.

“Once the recovery efforts are completed, the cannons will be analyzed to determine more information, such as type, age, and use. All cannons are believed to predate the Civil War era,” Birdwell told the Picket in an email.

The Picket recently posted an article about sonar survey and dives that have occurred since the February discovery.

The most recent were on the remains of Confederate “cribs,” or obstructions, placed in the river to prevent a Federal attack during the Civil War.

So what’s the story with the cannons found this year? Were they carried on warships or dumped into the water at some point?

Some theorize the three pieces found in February may have been carried by the HMS Rose, a British warship that took part in the siege of Savannah during the Revolutionary War.

The Rose was scuttled so as to block the channel from French ships that might come to the aid of colonists trying to retake the city.

That find was in the general vicinity of where the Rebel ironclad CSS Georgia was scuttled in December 1864 during the Civil War. Most of the ironclad’s wreckage was removed a few years back as part of the Corps’ deepening of the Savannah harbor.

More than a half dozen CSS Georgia artillery pieces have been pulled up over the years, but there could be a few more still in the river. And it’s possible some of the cannons were used at Fort Jackson, which was constructed in the early 1800s, or elsewhere and later discarded. The CSS Georgia served as a floating battery near Fort Jackson.

The Corps and contractors will try to determine the cannons’ provenance.

Asked whether the cannons explored last month could have been carried by the CSS Georgia or another period warship, Birdwell wrote, “While I understand this is technically possible, we haven’t done anywhere near enough research to say yes or no or anything more than ‘eh, maybe. Maybe not.’”

During their dives in mid-October, archaeologists also found part of an anchor and a bar shot, a type of munition designed to destroy ship rigging. They were commonly used during the Revolutionary War. (Above, James Duff with bar shot, photo: USACE Savannah)

The video briefly describes diving in the Savannah River. Crews using sonar and other technology guide divers to potential artifacts 45 to 50 feet below. Visibility near the bottom can often be nil.

A CSS Georgia Dahlgren gun found in 2015 (USACE)

“You are basically like an astronaut,” said Commonwealth archaeologist Andy Derlikowski. “You have your hard hat on … It’s a lot of just running around the sea floor until you physically encounter something on the bottom to identify.”

Birdwell said discussions are continuing on the final disposition of the cannons and other recently recovered items.

“The artifacts will be placed in temporary conservation while they are being analyzed, and decisions are still pending on potential conservation efforts,” he said.