Tag Archives: Charleston Harbor

Loss of Charleston’s floating battery

The December 21, 1863 edition of the New York Daily Tribune ran a column with news “From the Department of the South.”  The column’s leaders ran, “The Loss of the Weehawken – Explosion-Fire in Fort Sumter – Harbor Obstructions Washing Ashore – Shelling of Charleston – The Steamer Planter Still With Us – Discovery of a Brass Twelve-Pounder.”

Most of these I can provide links back to blog posts, with, given my advantage of 150 years, have more details analysis than the reporter’s few paragraphs:

But for the accounts of harbor obstructions washing ashore, there’s a bit of added mystery here which 150 years of collective research have not, in my opinion, offered much more than the reporter’s brief explanation:

On Saturday night [December 12?], during the storm, a wooden concern 50 by 30 feet, double planks on the bottom and sides, strengthened inside by beams a foot square, was washed ashore on this island one mile from Light-House Inlet. The general inquiry is “What is it?”  Gen. Turner, the able Chief of Artillery, gave it as his opinion that it was formerly a Rebel floating battery, as evidently shows signs where guns have been mounted, but of late has been used as an obstruction to the harbor, as very large stones are still in it, which seems to justify that belief.

The floating battery debuted during the weeks after South Carolina’s secession.  During the 1861 crisis in Charleston harbor, state authorities ordered the construction of a floating, armored battery, using recent examples from the Crimean War.  The presence of the battery caused quite a stir in the days before the shooting war started.

The battery mounted a couple of 32-pounder guns and two 42-pounder guns. The battery participated in the bombardment of Fort Sumter on April 12-14, 1861.

In action, the battery proved less formidable than made out in both the public eye and military minds.  The war’s inaugural battle proved the high point for the floating battery’s career.  By the time of the operations on Morris Island in 1863, the battery lost its iron plating for use on other projects (ironclads and “Davids”).  The guns went to conventional land batteries around the harbor.   The battery was thus more of a barge at that point, perhaps serving as an anchor point for rope obstructions.  Federal maps have it laying off the “Middle Ground” shoal in the harbor.


The map indicates Battery Ripley along with an “ironclad battery” and a “floating iron battery” on the shoal.  One of the later is likely the original floating battery.  Either location placed it in a position to be swept out in the main channel, given a very high storm tidal rush.

At any rate, after December 1863 there is scant reference to the floating battery. Some reports have it’s hulk surviving at the end of the war, laying off Morris Island.  If so, there is corroboration for the Tribune report.  I always keep this in mind, when reviewing the background of the Morris Island photographs, hoping to catch a glimpse of wreckage which might have been the floating battery.  But likely the wreck was at least partially broken up by Federals in need of wood that winter.

The obscurity of the floating battery’s demise is due in part to the Confederate reliance on obstructions and torpedoes as barriers in the harbor’s entrance.  By December 1863, Federal naval officers were far more concerned with the obstructions and torpedoes than the batteries, floating or otherwise.  On the same day the New York newspaper ran the story, Rear-Admiral John Dahlgren reported the recovery of some debris from those obstructions:

For ten days subsequent to the disaster of the Weehawken the weather was wretched, with the exception of a single day – wind, rain, and a heavy sea having prevailed in different combinations; one result of which has been to wash down a quantity of obstructions from the upper harbor, much to the discomfiture of the rebels, no doubt, not only depriving them of the aid they expected to derive from such means, but disclosing to us obstructions of another and more formidable character than those which we were aware of.

The quantity was very considerable, and besides those made of rope, which were well known to us, there were others of heavy timber, banded together and connected by railroad iron, with very stout links at each end.

I cannot undertake to say how these parts were combined, for, when I saw the timber in the channel, the iron connections were not visible, and when I saw the later ashore, the timer had been cut up for firewood.

But the solidity of strength of the wood and iron were obviously so great that they must have proved formidable obstructions to encounter.

I think it significant that Dahlgren does not mention the floating battery among the debris. Though, the hulk could have been “cut up for firewood” by the time he viewed the debris and thus unrecognizable.

Further down in the Tribune‘s report, the reporter recorded:

The storm that has been visiting us for the past few days is over.  To-day the weather is like Spring.  Often before I think I date my letters June or July. The coldest time we have is about 4 o’clock a.m.  Then the mercury is not low, but we are cold because of the great change that has taken place since noon of the previous day.

As I write this post, the high temperature predicted for Charleston is 74º.  Maybe mother nature is likewise celebrating the sesquicentennial with us?

(Dahlgren’s report is from ORN, Series I, Volume 15, page 185.)

Chevaux-de-frise and mountain howitzers: Improving Fort Sumter’s defense against landings

When built in the antebellum period, Fort Sumter could stand against the most likely threat to itself and Charleston harbor – wooden sailing vessels standing to bombard the fort.  But by the fall of 1863, the fort had fallen once to bombardment from land batteries (in April 1861), and was at that time being pounded into rubble by another bombardment.  Although this latest bombardment was the heaviest, up to that time, in American history, simple demolition of the walls and reduction of its armament would not neutralize the fort’s importance as a link in the defensive chain protecting Charleston.  The threat of sharpshooters and light cannon fire from Fort Sumter could deter any attempt by the U.S. Navy to clear the obstacles at the harbor entrance.

As Federal cannons destroyed more of the fort’s original structure, the likelihood of another direct assault by boat.  To counter that threat, Confederate defenders improved the existing defenses to include features and weapons not contemplated when Fort Sumter was built.  For example on the night of November 7-8, 1863, engineers recorded the following work done:

Force, 170 hands; discharged 2,700 bags of sand and some timber; repaired, raised, and enlarged traverse over west circular stairway; filled mortar holes on gorge bomb-proof and traverse in rear of northeast lower casemate battery.  Carpenters worked on ladders, ventilators, and chevaux-de-frise; being obliged to remodel the latter.  No wire fencing yet built, as the expected posts and frames have not yet arrived from the city.

I would point out that some of those “hands” were slaves requisitioned by the Confederates for such work.

In the Civil War context we normally consider chevaux-de-frise as an obstacle designed to stop cavalry:

But the threat to Fort Sumter was not the mounted arm.  Rather from marines, sailors and soldiers scaling up the rubble from boats.  The Federal bombardment would turn these into splinters in short order.  The Confederates needed something light enough to put out at night (or other times when landings were expected) and have a low profile to avoid damage.  Photos taken at war’s end show some of those modified chevaux-de-frise:

Notice the orientation of the “barbs” on these chevaux-de-frise.  Laying on a frame, the points would impede those scaling up the rubble.  At the base of the wall, to the left, are some of the posts for wire fencing mentioned in the report.

Another postwar view of the fort shows the modified chevaux-de-frise from above:

And this view also brings up two of several very light artillery pieces used by the Confederates as anti-landing weapons.  As the Confederates removed the heavy guns from the fort, these light field pieces came in to provide close range fire to cover potential landing points around the fort.  In this case 12-pdr mountain howitzers.  At night, these were wheeled out of hiding and placed appropriately around the fort’s battered parapet.  At daybreak they were moved back under cover for protection.  But that didn’t always ensure the howitzers were safe.  On November 8, Colonel Alfred Rhett wrote in the singular sense about “the” mountain howitzer employed in the fort, and damage to the weapon:

The mountain howitzer, though placed in a position of supposed security, was struck in the chase by a fragment of a mortar shell, causing a convexity in the bore.  This, I think, can be removed by boring out.  The piece was sent up per steamer Randolph last night and contains a round of case shot.

Notice the howitzer was loaded with case shot while employed in this role.  If I may again dig at my favorite target of late… not canister!  For preventing boat landings, case shot could reach out a bit further than canister and stop the enemy before touching ground.  I’m reminded of Rear-Admiral Dahlgren’s original experiments with boat howitzers and the use of case shot, prior to the war, in that regard.

Chevaux-de-frise, mountain howitzers, and other defensive measures transformed Fort Sumter from a seacoast artillery platform into a secure observation post and sharpshooter’s nest.  Arguably the transformation was a success, as the post would not fall to direct assault during the war.

(Citations from OR, Series I, Volume 28, Part I, Serial 46, pages 635-6.)

Ericsson’s Obstruction Remover tried again at Charleston

When the U.S. Navy attempted to pass Fort Sumter in April 1863, one feared component of the Confederate defenses were the obstructions and torpedoes anchored between Fort Sumter and Sullivan’s Island.  Seven months later and those obstructions still barred the Federals from Charleston harbor.  Rear-Admiral John Dahlgren cited them in his assessment of the situation in October of that year.  With approval to attempt another run past Fort Sumter, Dahlgren turned to a device designed by John Ericsson named “the obstruction remover” as a potential solution to the problem at hand.

Recall that in the failed attack of April 7, the Federals had used something from Ericsson nicknamed “the Devil” and called “the obstruction remover” in some correspondence.  What is not clear IN the correspondence from November 1863 is if the obstruction removers were one and the same.  Or if these were similar designations of different devices originating from the same inventor. A Confederate diagram of “the Devil” that washed ashore after the April attack shows chains and hooks suspended from a raft, shaped to fit onto the bow of a monitor:


However, Federal descriptions did mention explosive devices suspended in front of the raft.  These devices were intended to be placed upon the obstructions then triggered remotely to blast a path.  Descriptions of the obstruction remover tested in November 1863 focus on the explosive device and less so on the raft.  Thomas J. Griffin, serving as a technical inspector of ironclads, provided  description of the device as tested in November:

This obstruction remover consists of a cast-iron shell, or torpedo, about 23 feet long and 10 inches in diameter, containing 600 pounds of powder. This is discharged by a trigger board placed directly in front and extending the entire length of the shell, adjusted on the plan of a parallel ruler; this board, by being pushed in contact with obstructions, will spring two locks placed equidistant on the torpedo, causing an explosion of the shell. These torpedoes are suspended from rafts carried on the bows of monitors, and held in position forward by two booms, which are firmly secured to the raft; there is also attached to the forward part of the torpedo a series of air vessels, so arranged to cause the explosive powder to be expended in that direction.

When, on November 4, the USS Patapsco went off the gun line for repairs and a replacement Parrott rifle, Dahlgren ordered additional tests of the obstruction remover.  Commander T.H. Stevens, of the Patapsco reported two trials were conducted on November 6, “… one of which failed on account of the damaged condition of the powder, we succeeded yesterday in exploding the torpedo designed by Mr. Ericsson.”  Griffin offered a detailed examination of the tests:

As this trial was only made to show the effect of the explosion on the monitor, and how much it interfered with the maneuvering of the vessel, it was carried on in deep water.  The Patapsco, the vessel on which the trial was made, had, on account of the foulness of her bottom, only a speed of about 3½ knots; with the raft on, I should judge she was not to be driven more than 3 knots; and in making a circuit with the helm hard down, it takes at least half as much more room.

In exploding the torpedo, which was suspended at a depth of 13 feet, the shock was hardly perceptible on the Patapsco, while the body of water displaced and thrown upward to a height from 40 to 50 feet, was really fearful; this body of water was thrown forward, and but a slight quantity of water fell upon the deck of the vessel.  The raft was raised about 2 feet at the forward end, but sustained no material injury.

Both Stevens and Griffin considered the the obstruction remover tests successful.  However, both offered caution with respect to the maneuvering of the monitors with these devices fitted.  Griffin added that the three rafts on hand could be fitted out, save the torpedoes themselves, and set up “for use at short notice.”

The idea of using an explosive device (and a rather large one in this case) to clear obstructions and mines is practical, to say the least.  In fact, that basic idea is in use today, on land, in the form of the Mine Clearing Line Charge (MICLIC):


The line charge is a bit more sophisticated, with a rocket pulling a line.  The charge is five pounds of C-4 explosive per linear foot.  The explosive line is triggered electrically and remotely (not on contact as with the Ericsson device).  Bigger boom, to say the least.  Principle is the same – the explosion clears mines and obstacles to form a safe path about 25 feet wide.

But in 1863, the Navy didn’t have rockets to put the charge at the necessary point. To bring the Ericsson Obstruction Remover into position, the ironclads would need to navigate the confined and dangerous waters at the mouth of Charleston harbor.  Events in mid-November would demonstrate just how difficult that would be, even with Fort Sumter suppressed.

(Citations from ORN, Series I, Volume 15, pages 102-3.)

The ever shrinking armament of Fort Sumter

In April, 1863, Fort Sumter repulsed an attack by Federal ironclads using forty-four guns. After that crisis past, the fort received a few new heavy guns. By the end of June, the fort bristled with sixty-four guns and four mortars. While General P.G.T. Beauregard would have preferred more of the heavy guns, particularly Brooke rifles, the fort remained a formidable obstacle blocking Federal attempts to reach Charleston harbor.

But with the Federals in possession of the southern two-thirds of Morris Island, the handwriting was on the wall. As a harbor defense, Fort Sumter’s days were numbered. Starting in July, Beauregard directed the reduction of Fort Sumter’s valuable heavy ordnance. If the Federals were soon to reduce the work, better to salvage those guns for work elsewhere in the harbor defenses.

According to John Johnson, who was a lieutenant during the campaign, serving as an engineer, and later wrote The Defense of Charleston Harbor, at the time of the August bombardment, Fort Sumter’s armament was reduced to thirty-eight guns and two mortars:

  • West flank barbette – two IX-inch Dahlgren guns
  • North-west face barbette – two 10-inch columbiads, two 8-inch columbiads, and four 42-pounders.
  • North-eastern face barbette – two 10-inch columbiads, and five rifled 42-pounder.
  • East flank barbette – one XI-inch Dahlgren and four 10-inch columbiads, one 8-inch columbiad, one 7-inch Brooke, and one rifled 42-pounder.
  • Gorge barbette – five rifled 32-pounders and one 24-pounder.
  • Salient casemate – three rifled 42-pounders.
  • Lower tier casemates on northwest and northeast flanks – two VIII-inch Dahlgrens and two 32-pounders.
  • Parade field – two 10-inch mortars.

Colonel Alfred Rhett provided a table detailing the distribution of Fort Sumter’s guns from the start of July through early September:


First line down, the XI-inch Dalhgren was one of those recovered from the USS Keokuk earlier that spring.

In his remarks about this table, Rhett explained the “left uninjured” weapons were buried in the fort’s remains. Most of those, he felt, were actually injured but could not confirm. At the time of this report, just before the evacuation of Battery Wagner, only one 32-pounder smoothbore, on the northwest casemate tier, was operational. All the remaining guns were buried, incapacitated, or transferred out of Fort Sumter.

The disarming of the Fort Sumter gave some sectors of the Confederate defenses a much needed boost. The biggest beneficiaries of the distribution were the batteries on James Island. The fourteen guns going to the batteries there included eight columbiads, a Brooke rifle, and four VIII-inch shell guns. A dozen guns went to the batteries in Charleston itself, finally giving the inner harbor a credible defense. Four more columbiads on Sullivan’s Island added weight to that flank’s already formidable armament. But a mortar and a rifled 32-pounder transferred from Fort Sumter would end up among the weapons given up in the withdrawal from Morris Island.

As these guns came out of Fort Sumter, the Confederate engineers filled casemates and other open spaces with sand and other materials to buttress the fort’s walls. Quaker guns kept the Federals from knowing the exact details about the fort’s disarmament. By the first week of September, Fort Sumter was little more than a symbol of defiance, lacking its former position as the centerpiece of the Charleston harbor defenses.

150 years ago: “…open fire on Fort Sumter when within easy range…”

On April 4, 1863, Rear-Admiral Samuel DuPont wrote orders for the long anticipated ironclad attack on Charleston harbor.

Flagship James Adger

North Edisto, South Carolina, April 4, 1863

The bar will be buoyed by the Keokuk, Commander Rhind, assisted by C.O. Boutelle, assistant, U.S. Coast Survey, commanding the Bibb; by Acting Ensign Platt, and the pilots of the squadron.

The commanding officers will, previous to crossing, make themselves acquainted with the value of the buoys.

The vessels will, on signal being made, form in the prescribed order ahead, at intervals of one cable’s length.

The squadron will pass the main Ship Channel without returning the fire of the batteries on Morris Island, unless signal should be made to commence action.

The ships will open fire on Fort Sumter when within easy range, and will take up a position to the northward and westward of that fortification, engaging its left or northwest face at a distance from 600 to 800 yards, firing low and aiming at the center embrasure.

The commanding officers will enjoin upon them the necessity of precision rather than rapidity of fire.

Each ship will be prepared to render every assistance possible to vessels that may require it.

The special code of signals prepared for the ironclad vessels will be used in action.

After a reduction of Fort Sumter it is probable that the next point of attack will be the batteries on Morris Island.

The order of battle will be the line ahead in the following succession:

  1. Weehawken.
  2. Passaic.
  3. Montauk.
  4. Patapsco.
  5. New Ironsides
  6. Catskill
  7. Nantucket.
  8. Nahant.
  9. Keokuk.

A squadron of reserve, of which Captain J.F. Green will be the senior officer, will be formed outside the bar and near the entrance buoy, consisting of the following vessels:

Canandaigua. Wissahickson. Housatonic. Houron. Unadilla.

And will be held in readiness to support the ironclads when they attack the batteries on Morris Island.

S.F. DuPont,

Rear-Admiral, Comdg. South Atlantic Blockading Squadron.

Once disseminated, the warships had to wait for weather, wind, and tides for the right time to sortie.  Several interesting aspects within DuPont’s orders – marking the channel, signal coordination, order of movement, intended ranges, and the posting of reserves.  But consider the firing instructions.  Slow, aimed, and deliberate.  For the initial target, Fort Sumter, the fires were to concentrate on a specific point in the middle of the fort’s face.  In other words, the objective was a breach of the wall.  Contrast those instructions to those used a year before at Fort Pulaski.

And the objective of these fires was the “reduction” of Fort Sumter.  Not “silencing” or “neutralizing” but reduction.  The word has a specific meaning and a specific intention.

(DuPont’s orders are from the Naval ORs, Series I, Volume 14, pages 8-9.)

Battlefields in Motion: Fort Moultrie

Charleston, South Carolina will soon return to our Civil War Sesquicentennial stream.  In our queue are the anniversaries of the events such as the Confederate ironclad sortie, the Federal ironclad assault on Fort Sumter, and the siege of Battery Wagner.  That in mind, any new resources for the “battlefield” at Charleston are welcome additions.

The team at Battlefields in Motion have put together a very useful resource offering a detailed study of Fort Moultrie – an important component of the Charleston battlefield.  Pages covering the pre-war period in the fort’s history are posted, along with several good articles on the artillery that armed the fort.  As are a set of videos:

Also useful for those “looking back” are a set of stills based on the CGI from the videos.  These allow a reader to look back in time at a fort which has undergone so many transformations over the years.

A good link to bookmark.  Many thanks to the Battlefield in Motion crew, and keep up the good work!

Mapping the Charleston Battlefield

From the University of South Carolina’s website:

Mapping Charleston’s Civil War Naval Battlefield

What remains of a five-year siege for control of Charleston Harbor during the Civil War now lay in watery graves amid the harbor’s channels and under the beaches of bordering sea islands.

Thanks to a team of archaeologists at the University of South Carolina, the Charleston Harbor naval battlefield has been mapped for the first time, providing historical and archaeological detail on the drawn-out struggle that spanned 1861-1865. The survey shows where military actions took place, where underwater obstructions were created to thwart enemy forces and the spots where Union ironclads and Confederate blockade runners sunk.

The National Park Service, which funded the project through an American Battlefield Protection Program grant with matching funds from USC, will use the survey to preserve the battlefield. Information gathered about the wrecks and obstructions also will be valuable to harbor managers, the U.S. Army Corps of Engineers and to USC archaeologists to ensure that underwater relics aren’t damaged. Their work will also be considered in decisions involving beach renourishment and the deepening of the harbor.

“The archives of South Carolina’s maritime history are under water. For years we have had these great resources that we should hold in as much respect as historical documents,” said James Spirek, a USC underwater archaeologist. “They are the physical representations of the state’s maritime legacies.”

Spirek directed the project that began in 2008 and wrapped up this spring. He applied the same approach that was used to understand the historic landscape of Gettysburg to understand the Civil War naval operations at Charleston Harbor.

“The scheme, called KOCOA, is a modern concept based on ages-old military tenets that gets archaeologists and historians to think about how the participants saw the battlefield,” Spirek said. “Today, all we see is the aftermath. But how did the battle come to be? And why are things where they are in Charleston Harbor?”

To answer those questions, Spirek had to define the boundaries of the harbor battlefield from the perspective of Union and Confederate forces. He conducted research on Confederate and Union ships and naval actions using official records of the armed forces, the National Archives, Library of Congress and USC’s South Caroliniana Library and Digital Collections.

His archaeological work centered on locating the various shipwrecks and obstructions. Two key findings were locating the famous First Stone Fleet, a series of New England whaling and merchant vessels filled with stone and intentionally sunk by Union forces to prevent Confederate blockade runners from entering the harbor, and getting exact locations for the blockade runners, most of which sank in Maffitt’s Channel along Sullivan’s Island. (Read More)

For those non-military types, KOCOA is an acronym, more a mnemonic device – standing for Key terrain, Observation and fields of fire, Cover and concealment, Obstacles, Avenues of approach – which describes the evaluation criteria for terrain analysis.  If you are going to talk about a battle, and hence a battlefield, then you must discuss these aspects of the terrain.  As my naval counterparts would agree, these elements of terrain analysis hold true in the littorals as they do on land.  So Charleston is a perfect place to apply KOCOA.

The project has a website offering some fruits of the study.  There’s already a virtual tour using a map of the harbor:

As the news release states, Charleston was the war’s longest continuously fought over objective.  There’s more to the city’s wartime story than just Fort Sumter.