Daniel Ammen, Confederate Military History, a library of Confederate States Military History: Volume 7.2, The Atlantic Coast
Clement Anselm Evans, Ed.

[159] great many barrel torpedoes fitted for placing in that channel-way and off Charleston with the least possible delay. They were of the same construction as those which had sunk three army transports in St. John's River, the monitor Patapsco off the harbor on January 15th, and the flag-ship Harvest Moon below Georgetown after the fall of Charleston. These barrel torpedoes were held by their moorings some eight feet below the ordinary surface of the water, and were fitted so as to explode on contact.

On the wharf at Charleston was found one of these inclined frames ready for use, with thirty torpedoes fitted for it; they also were constructed to explode by contact.

A boiler torpedo, probably of English fabrication, was found on the wharf ready for charging, together with a large quantity of insulated copper wire protected by a hemp wrapping overlaid with wire.

The torpedoes made for the ironclads, or rams, as they were called, and for the torpedo-boats, were elongated copper cylinders ten inches in diameter, with hemispherical ends, thirty-two inches long, each having several screw sockets for eight fuses so as to present points of explosion widely separated. The charge was one hundred and thirty-four pounds of powder.¹

Another was of copper, barrel-shaped, tapering to points on the ends; it had sockets for seven fuses on the upper bilge, and contained one hundred and thirty-four pounds of powder.1

During the autumn of 1863 reconnoitering boats were sent almost nightly, when the weather permitted, into the mouth of Charleston Harbor, and diverse reports were brought to the admiral in respect to the character of the channel obstructions.