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

On board of the Nahant, the compresser of the Xv-inch gun became disarranged at various times, and at the twentieth discharge, the rivets securing the brass guides on the after-part of the carriage gave way, the guides falling down into the turret-chamber, without, however, disabling the gun. A cast-iron ‘yoke’ put in to allow the use of an Xi-inch gun temporarily on a carriage made for a Xv-inch gun was broken at the thirty-ninth discharge, thus disabling the gun until a new ‘yoke’ could be put in. The foundries were not able to furnish a sufficient number of Xv-inch guns when the vessels were completed, hence the temporary use of a smaller calibre, and the fitment of a ‘yoke’ to hold the trunnions of a smaller gun. It should have been made of bronze, cast-iron not having the tenacity to resist the strain brought upon it. The rifle of the Patapsco had, months before, carried away its ‘yoke’ in like manner, and the Ordnance Bureau, being thus informed, had bronze ‘yokes’ sent down, which were substituted, and cured that defect.

After the bombardment the vessels withdrew, as did the mortar schooners and the gunboats Seneca, Wissahickon, and Dawn, that had laid two miles from the fort to signal the effect of the shells.

On the 6th, early in the day, the Passaic, Patapsco, and Nahant left Ossabaw Sound in tow of suitable vessels, and the same evening entered Port Royal Harbor.

The Passaic was at once put under repairs, which were not fully effected until the 28th. She also had a bronze ‘yoke’ put in to avoid a future mishap, such as the Patapsco and Nahant had undergone. The last-named, and indeed all of the monitor class, had bronze ‘yokes’ placed in the carriages upon which the Xi-inch guns were mounted. All of them, too, had one-inch plates of iron placed over the