At the start of the Third Major Bombardment of Fort Sumter, Major-General John Foster had in mind a plan to level the fort by way of a large explosive device. “As soon as a good cut is made through the wall,” Foster wrote to Washington on July 7, 1864, “I shall float down against it and explode large torpedoes until the wall is shaken down and the surrounding obstructions are entirely blown away.”
Seven weeks later, the desired “cut” was evident, but the torpedoes were yet to be employed. Early in the bombardment, Foster called upon the Navy for support, as they were somewhat more experienced with floating demolition devices and torpedoes. On July 21, 1864, the USS Nahant attempted to push an explosive laden barge into position. But miscommunication and bad weather thwarted the attempt. After this failure, the Navy, particularly Rear-Admiral John Dahlgren, became disenchanted with the whole idea.
Brigadier-General Alexander Schimmelfennig, in command of the forces in front of Charleston, continued with the plans as directed. Using his special relation with the Admiral and other naval officers, Schimmelfennig received technical support while troubleshooting the torpedo clocks that timed the explosive device. By the close of August, the explosive devices were ready for employment. The first of these devices was a raft, filled with explosives and fitted with a torpedo clock. It would be towed out to Fort Sumter and pushed into position.
Reporting on the first effort, which took place on the night of August 28, 1864, Schimmelfennig wrote:
On the night of the 28th ultimo, a pontoon-boat, fitted up for the purpose and containing about twenty hundredweight of powder, was taken out by Lieut. G.F. Eaton, One hundred and twenty-seventh New York Volunteers, boat infantry, and floated down into the left flank of Fort Sumter. The garrison of Sumter was alarmed before the mine reached them, and opened upon our boats with musketry, without, however, doing them any injury.
At 9:15 p.m. that night, Captain Thomas A. Huguenin, Confederate commander of Fort Sumter, reported the first torpedo attack. “The enemy floated a torpedo down from direction of [Fort] Johnson, which exploded near our wharf; no damage as far as ascertained yet.” Huguenin went on to suggest the Federals had caught onto the Confederate passwords, perhaps alluding to how the Federals had gotten so close to Fort Sumter without any challenge.
Two nights later, the Federals tried again with different equipment:
On the night of the 31st ultimo six torpedoes, made of barrels set in frames, each containing 100 pounds of powder, were set afloat with the flood-tide from the southeast of Sumter with the view of destroying the boom. They probably exploded too early and only injured perhaps two lengths of the links of the boom, which are now not visible.
At Sumter, Huguenin reported, on September 1, “The enemy again attempted to blow up the fort with a torpedo, but failed. The torpedo exploded about 300 yards off the east angle.”
Although picking at a weak corner of the fort, the means to place the explosive were faulty. In the end, these Federal efforts came to naught. So the long bombardment of Fort Sumter continued through September.
(Citations from OR, Series I, Volume 35, Part I, Serial 65, pages 15, 74, 239, and 240.)