Monday, March 7, 2022

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.


  1. The Corps, I believe, has custody as decisions are made on possible conservation.