Johnson’s defense

Ordnance, obstructions and torpedoes

What the guns were, what they did to five feet of brick, and what stopped a fleet without firing at it.

Johnson is an engineer writing about guns, and the difference shows: he is less interested in what a piece could do than in what it did to what it hit, measured afterwards with a rod. The figures below are his — armament returns, ranges, penetrations, and the counts of shot and shell kept inside Fort Sumter day by day.

The central fact of the ordnance in this book is a mismatch. Against XV-inch and XI-inch smoothbores and 8- and 10-inch rifles, the Confederate artillerists had nothing heavier than 10-inch smoothbores and 7-inch Brooke rifles, and they knew it. What they had instead was range knowledge, powder from Rains's works at Augusta, and a harbor whose obstructions frightened the Federal navy more than its guns did.

On why straw bedding had been left in the eastern barracks, where a shell set fire to it on 7 April 1863:
“it was thought that no single shell could breach the wall”
Johnson, p. 50

The guns

The 300-pounder Parrott

10-inch rifle · one gun · 4,290 yards to Fort Sumter

The single most destructive piece fired at the fort. It took a week for the 100- and 200-pounders to destroy a casemate arch; on 30 August 1863 this gun did it in eight hours, bringing down the terreplein with gun and carriage, and on 1 September it dropped four upper casemates at one fall. It was disabled soon after opening by a shell bursting at the muzzle, which took off about eighteen inches; repaired, it fired three hundred and seventy times more without any noticeable loss of range or accuracy, and was finally destroyed by more of the same. Getting it into position took a week, three broken sling-carts and a mile of deep sand.

The breaching batteries

eighteen rifled guns in eight batteries · 3,428 to 4,290 yards

Two 80-pounder Whitworths, nine 100-pounder Parrotts, six 200-pounders and the 300-pounder, throwing a ton of metal at each discharge. Johnson prints Turner's table of them — Brown, Rosecrans, Meade, the Naval Battery, Hays, Reno, Stevens and Strong — with the armament, range and garrison of each. Breaching at four thousand yards had never been done; the Federal batteries that took Fort Pulaski in 1862 had worked at 1,700.

The XI- and XV-inch Dahlgrens

smoothbore, naval · 440-pound projectile from the XV-inch

The armament of the monitors, and the guns that did what the land batteries could not: hit the sea face square on instead of at a slant. Johnson watched them from the parapet on 7 April 1863, and wrote afterwards that no one in the garrison would forget the size of those black spheres bounding in full view from the ports of the turrets to the walls of the fort. Two of them, an XV- and an XI-inch, went entirely through the weakest part of the scarp wall that day and burst inside.

The Keokuk's guns

two XI-inch Dahlgrens · 16,000 pounds each · recovered from the wreck, May 1863

Cut out of a sunken turret at night and turned on their former owners: one mounted at Fort Sumter's eastern angle, fired there until the night attack of 1–2 September 1863, and afterwards placed in Battery Ramsay at White Point Garden; the other in Battery Bee on Sullivan's Island, where it fought the action of 8 September and stayed to the end. They were the heaviest guns in the harbor.

The 7-inch Brooke rifles

Confederate · 30- to 34-pound shells · effective at 6,160 yards

The heaviest rifled pieces Fort Sumter had, mounted en barbette at the south-eastern and northern angles, and the guns that fired on the Federal working parties three and a half miles down Morris Island through July 1863. Johnson gives their charges and elevations exactly — 20 degrees, fifteen pounds of powder — and then records the failure: on the fifth day of firing the south-eastern gun showed a fracture in the breech along the ratchet marks, and only the band held the ruined piece together.

The rifled and banded 32-pounders

old smoothbores rebored and banded at Eason's works, Charleston

The Confederate answer to having no heavy rifles: take the 32-pounders out of the casemates and remake them. Mounted en barbette on the gorge, fired at 14 degrees with seven and a half pounds of powder and a 25-pound shell, they reached 4,800 yards. Guns of this class were still being mounted in Fort Sumter's west battery in February 1864.

The Whitworth sharpshooters' rifles

small arms with telescopic sights, run through the blockade

Used from the walls of Fort Sumter against the artillerymen on Cumming's Point at thirteen hundred yards — Johnson calls the disparity in weight of metal prodigious and the results quite satisfactory. Federal sharpshooters had used the same rifles from Battery Wagner against Gillmore's working parties the year before.

The Marsh Battery — the Swamp Angel

8-inch Parrott rifle · 7,900 yards to Charleston · burst on the 36th round

A single heavy rifle on a platform driven into a salt marsh on piles, with the parapet's sandbags acting as a counterweight against the gun's own tendency to sink. It opened on the city before daylight on 22 August 1863. Johnson's footnote follows the gun to the pedestal it stands on in Trenton, New Jersey, and quotes the inscription — which records, without a single punctuation mark, that it burst on the thirty-sixth round.

The obstructions, which were not what the navy thought they were

The rope obstruction was three cables ratlined together like the shrouds of a ship — the upper one floated and streaming slack lines to foul propellers, the lower anchored and doing the same — with an array of beer-barrel floats along it. It was placed between Fort Sumter and Battery Bee, not between Sumter and Moultrie as the accounts have it, and it had dragged a little below the line of Battery Bee. In April 1863 there were no torpedoes among it or in front of it, and there was a gap three hundred yards wide, next to Fort Sumter, entirely clear of everything.

The heavy timber boom that preceded it, coupled with iron and anchored across the channel between Moultrie and Sumter, was broken twice by the tideway and abandoned. Piling across the Middle Ground, driven in 1862, decayed continuously and was renewed to the end of the war.

None of it would have stopped a determined ship, and all of it stopped the squadron. Johnson's judgment is that many will always believe the whole of Du Pont's squadron would have turned back from the rope obstruction even if the forts had never fired a gun. The Federal navy did not examine the obstructions with small boats at night until January 1865, and the examination cost it the Patapsco.

Torpedoes, spar and fixed

Fixed torpedoes went into the Ashley in March 1863 by Beauregard's order, and into Hog Island Channel and Folly Channel; the large boiler torpedo — eighteen feet long, three feet in diameter, three thousand pounds of powder — was laid in the main ship channel about half a mile off Battery Wagner. On 7 April the New Ironsides is thought to have stopped directly over it. Langdon Cheves, at the firing post, tried to explode it and could not, and why it did not fire was never discovered.

The spar torpedo was Captain Francis D. Lee's: fifty to a hundred pounds of powder in a watertight case on a spar twenty-five or thirty feet long, pushed under water against a ship's side. Lee also designed the armored torpedo ram that South Carolina paid $50,000 for and that was never finished, and which Johnson calls the real precursor of the torpedo boats of the world's navies. What the harbor got instead were the David and the fish boat.

Johnson's footnote carries the best definition anyone gave the weapon: that a torpedo attacks matter and mind at once.

The ironclad rams built at Charleston

Four were built between 1862 and 1865. The Palmetto State, four-inch plating, an 80-pounder rifle forward, a 60-pounder aft and an VIII-inch shell gun on each broadside; the Chicora, with two IX-inch smoothbores and four 60-pounder rifles; the Charleston, completed early in 1864; and the Columbia, with six inches of plate, completed early in 1865, disabled by an accident, and never in service.

Johnson's assessment is unsentimental: the boats were well built, their steam power was insufficient for the speed a ram needs, and their engines wanted constant repair. On 31 January 1863 the first two of them went out before daylight, disabled two blockaders that surrendered and then escaped in the dark, and held the sea for nearly twelve hours without a casualty. It was as much as they ever did, and the claim that they raised the blockade was never sustained.

What Fort Sumter was armed with, and when

*April 1863* — 40 guns in casemate and 45 in barbette, with 7 mortars: 85 guns in all, of which Johnson reckoned 24 could be effective against armor.

*End of July 1863* — 38 guns and 2 mortars, more than twenty pieces having been taken out and sent to the new works of the inner harbor.

*23 August 1863 — one gun in good condition, the recovered Keokuk* XI-inch, and two partly serviceable.

*1–2 September 1863 — none. The last two 10-inch columbiads had gone over the wall the night before, and the fort took a five-hour attack by six monitors and the New Ironsides* without a reply.

*October 1863 — three heavy guns in the lower casemates of the north-eastern face: the three-gun battery*, protected from reverse fire and never brought into action, but covering the channel to the end.

*February 1864 — three more in the casemates of the city front: the west battery. Mounting them cost the fort its evening gun*, the 32-pounder that had been fired at sundown for months and was for most of that time the only gun fired in Fort Sumter at all.

What the guns did to the masonry

Fort Sumter's scarp wall was five feet thick, backed by the arches and piers of the casemates; the parapet on the gorge was four feet three inches, the thinnest part of the work. The best Carolina gray brick, a concrete of pounded oyster shell and cement, and a harder composition used only for the embrasures.

On 7 April 1863 the squadron made thirty-four hits and about twenty other marks; fifteen shots did the actual damage; the penetrations in the original brickwork averaged one to two and a half feet, with craters about three feet across. On 12 August 1863 a single 8-inch bolt opened a crater three feet across and one and a half deep and went three feet four inches further, so that the measuring rod was stopped by the base of the shot, nearly through the wall.

By December 1863 the sea face had gone from a perpendicular wall forty feet high to an irregular mass of rubbish averaging twenty feet above tide with a crest six feet wide. By July 1864 it was in places at or below the level of the lower embrasures, about five feet above the tide — and it was the one face the Federals never concentrated on.