Charleston Harbor Site

A. Roy

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Raleigh, North Carolina
Interesting period map, it was certainly a very heavily defended harbour. I'm sure every battery or fort or was placed in a very specific location to cover various fields of fire.

I'm amazed at how extensive the Charleston fortifications were. I've been reading Earl Hess's book Field Armies and Fortifications in the Civil War. He includes a fascinating and detailed discussion of how the Union forces finally reduced Fort Wagner on Morris Island -- not by storming it with frontal attacks, but by the slow, meticulous, and arduous construction of trenches.

Roy B.
 

NFB22

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Location
Louisville, KY
I'm amazed at how extensive the Charleston fortifications were. I've been reading Earl Hess's book Field Armies and Fortifications in the Civil War. He includes a fascinating and detailed discussion of how the Union forces finally reduced Fort Wagner on Morris Island -- not by storming it with frontal attacks, but by the slow, meticulous, and arduous construction of trenches.

I've always been intrigued at the fact the United States spent a great deal of time and money building up third system fortifications prior to the war but when it came down to it, they really didn't stand up to the artillery of the time. Time and time again they were battered into submission (Fort Pulaski, Fort Morgan, Fort Jackson, etc) or virtually destroyed (Fort McRee, Fort Sumter) in short periods of time.

Meanwhile, the earthwork fortifications that ringed Charleston Harbor held out nearly the entire war.
 

A. Roy

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Meanwhile, the earthwork fortifications that ringed Charleston Harbor held out nearly the entire war.

Why do you think that is? I wonder whether the problem might have been partly that the third-system forts were kind of a standard top-down central government effort, whereas the Charleston Harbor works you're talking about were meticulously developed based on intimate knowledge of the terrain.

Roy B.
 

NFB22

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Louisville, KY
Why do you think that is? I wonder whether the problem might have been partly that the third-system forts were kind of a standard top-down central government effort, whereas the Charleston Harbor works you're talking about were meticulously developed based on intimate knowledge of the terrain.

I would say look at Fort Moultrie. The defenders basically just surrounded it with sand to absorb the constant bombardment from Federal guns and then rolled sod over the top to keep it in place. I'm not quite sure why this type of method wasn't used more extensively by military engineers prior to the war, at least when the ground allowed for such works to be constructed. Naturally one would think properly constructed earthwork fortifications would absorb bombardment better than masonry structures alone.

In Charleston's case, this method was used long before the 1860s when British warships attacked early during the American Revolution and a fort on Sullivan's Island constructed of wood and earth held off the fleet. Probably why when the city was attacked later in the war the British forces didn't try that approach again.
 

KianGaf

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Dublin, Ireland
I've always been intrigued at the fact the United States spent a great deal of time and money building up third system fortifications prior to the war but when it came down to it, they really didn't stand up to the artillery of the time. Time and time again they were battered into submission (Fort Pulaski, Fort Morgan, Fort Jackson, etc) or virtually destroyed (Fort McRee, Fort Sumter) in short periods of time.

Meanwhile, the earthwork fortifications that ringed Charleston Harbor held out nearly the entire war.

Pulaski in particular proved the era for traditional forts had ended.
 

Tom Elmore

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Last edited:

John S. Carter

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Mar 15, 2017
@KianGaf and @Rusk County Avengers -- I compared this structure with the 1891 US War Dept map of the Charleston defenses, and, as I thought, this location on the north of James Island seems to have been submerged at the time of the Civil War. I think the coastline around the harbor has changed considerably over the years -- for example, Morris Island has eroded quite a bit, threatening the sites of Batteries Wagner and Gregg.

Here's a Google sat map showing that structure close to the center of the triangle of Forts Johnson and Sumter and Battery Simkins:

View attachment 367020

And here's a detail from the 1891 War Dept map, which indicates that that location was under water at the time of the war. (By the way, the War Dept map was not oriented north-to-south in the customary manner, so I rotated it to orient to the Google map.)

View attachment 367021

That square also seems like an unlikely shape for a fort, but I don't know everything about fortifications. I'm wondering whether there are some Charleston experts here at CivilWarTalk that might be able to chime in.

@NFB22 might have an opinion also, or know someone familiar with the area. He put together a nice thread on Fort Johnson a while back:

https://civilwartalk.com/threads/forgotten-forts-series-fort-johnson-sc.102188/#post-914372
Roy B.
From what area did the first shots come from by the Rebels?
 

Snowbound

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May 6, 2019
Pretty sure this is a spoil area from past dredging operations. Berms are often constructed. Look at the area east and west of the Ben Sawyer bridge between Mt Pleasant and Sullivan's Island. There are several created from dredging the Inter-coastal waterway. I grew up in Charleston and remember these in the 60s when none were occupied. Its also not far from where the steamship Sumter would travel when rotating troops between FT Wagner and Ft Johnson. My wife's great grandfather and the 23rd Georgia were passengers on the night in 1863 when this vessel was forced to sail CCW around Ft Sumter because of tides. They were a victim of friendly fire from Sullivan's Island.
 

A. Roy

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Raleigh, North Carolina
Pretty sure this is a spoil area from past dredging operations. Berms are often constructed. Look at the area east and west of the Ben Sawyer bridge between Mt Pleasant and Sullivan's Island. There are several created from dredging the Inter-coastal waterway.

That makes sense. In other words, this could be a disposal site for dredged material. The berm would have been build for containment. Here are sat images of the areas I think you're referring to near the Ben Sawyer Bridge. I can see a similarity in construction. This to the west of the bridge:

DredgeSpoilArea.png


These to the east:

DredgeSpoilArea2.png


Roy B.
 

mjr251

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Location
Near Port Arthur, Texas
Sorry for the late reply, but I agree that it's a dredge spoil site. I duck hunt in one down here on the Texas coast. Last season was ruined because they put one of those sluice gates in a corner, and drained all the water.

Though it's already been established that the site didn't exist during the ACW, I agree that it's way too big and improperly shaped to be an ACW work. It's even bigger than Sumter!
 

Rusk County Avengers

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Coffeeville, TX
Sorry for the late reply, but I agree that it's a dredge spoil site. I duck hunt in one down here on the Texas coast. Last season was ruined because they put one of those sluice gates in a corner, and drained all the water.

Though it's already been established that the site didn't exist during the ACW, I agree that it's way too big and improperly shaped to be an ACW work. It's even bigger than Sumter!

No it was Mega-Fort Sumter...
 

NFB22

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Jun 21, 2012
Location
Louisville, KY
I would say look at Fort Moultrie. The defenders basically just surrounded it with sand to absorb the constant bombardment from Federal guns and then rolled sod over the top to keep it in place. I'm not quite sure why this type of method wasn't used more extensively by military engineers prior to the war, at least when the ground allowed for such works to be constructed. Naturally one would think properly constructed earthwork fortifications would absorb bombardment better than masonry structures alone.

In Charleston's case, this method was used long before the 1860s when British warships attacked early during the American Revolution and a fort on Sullivan's Island constructed of wood and earth held off the fleet. Probably why when the city was attacked later in the war the British forces didn't try that approach again.
Thoughts on this idea of engineering, @jrweaver ?
 

jrweaver

Corporal
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Dec 9, 2020
The key to the whole thing was whether the fort could be reached by land-based cannon. The larger smoothbore and new rifled guns extended the range such that previously invulnerable masonry became vulnerable, such as Fort Pulaski. Guns on Tybee Island used to be out of range for the fort, so the walls toward Tybee were not protected by an earthen coverface. The new guns, however, could reach the fort with significant energy to eventually breach the masonry.
Third System forts were designed with bare masonry to seaward, which allowed better direct fire on ships and ship-based cannon were not a threat to bare masonry. This was proven in different wars, and confirmed in the ironclad (armed with rifled cannon) on Fort Sumter. The ironclads lost - one sunk, one sunk the next day from battle damage, the other two escaped - with minor damage to the fort.
By the end of the Third System, it was known that something needed to be done to accommodate the larger cannon, many of which would not fit in casemates. The solution - for a variety of reasons, not the least of which was cost - was masonry-revetted earthworks, open-topped, with earthen traverses containing magazines between each pair of guns. This artificial setup at Fort Moultrie is an example of that doctrine, called the 1870s Modernization Program. The weapon had now become more important than the fort that was to protect the weapon.
In 1886, the launch of the Endicott Program using concrete emplacements and steel cannon obsoleted all previous fortification programs.

IMGP3272.JPG
 

jrweaver

Corporal
Joined
Dec 9, 2020
One of the few forts built during the 1870s Modernization Program was Battery Cavallo on the north side of the Golden Gate, in what is now the Fort Baker portion of Golden Gate National Recreation Area. While named Battery Cavallo, it is actually an enclosed fort, albeit an earthwork fort.

It is an incredible work that set's the standard for a heavily armed redoubt! While it is masonry-revetted earth, it was to mount the largest guns of the day. In fact, it was designed for three 20-inch Rodman guns. Only two (or four, historians disagree) of these behemoths were ever made. They were not mounted at Battery Cavallo, but the fort was designed for them. Two 20-inch guns exist, one at Fort Hancock on the Sandy Hook of New Jersey and one at Fort Hamilton, at the Narrows leading to New York Harbor.
In addition to these massive guns, Battery Cavallo was designed to mount ten 15-inch Rodman guns, themselves very large cannon. It also was designed for two 12-inch Parrott rifles. This fort was designed for the heaviest armament in existence at that time!

Historian John Arturo Martini did a great sketch of the fort; I colorized the sketch and added some cannon to his work.
Battery Cavallo Color Rev 02.jpg


The fort is off limits, so please do not attempt to visit this site. I obtained special permission to photograph the site; I've included a number of photos on this post. If more photos are desired, please contact me and I will gladly provide them to you.


These are the remains of two of the 15-inch gun positions.
15-inch gun positions.jpg

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The parade of the fort is divided by traverses, protecting the flanks of the gun positions.
IMGP2809.JPG


There are a number of earth-covered galleries that allowed artillerymen to move about the fort under cover. Many of these had access to earth-covered magazines for the powder for the massive cannon.
Two galleries.jpg

Gallery.jpg


This is the entrance to one of the magazines that is reached through a gallery. It is now boarded over.
Magazine Entrance.jpg


Other magazines were entered directly from the parade of the fort.
IMGP2815.JPG


Battery Cavallo can be viewed legally, and quite well, from the viewing platform on the north side of the Golden Gate Bridge.
IMGP4125.JPG
 
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