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.)