Bad fuzes, and an intercepted signal
Major Manigault complained again in his journal of the bad quality of the shell fuzes, and reported the Marsh Battery repaired and its gun no longer visible. Confederate signal operators on Sullivan’s Island intercepted a Federal dispatch arranging for the New Ironsides to hoist a red flag when she began rapid fire “at the moment of assault to-morrow at about 9 o’clock.”
Journal of Operations in Charleston Harbor, OR I, 28, Pt. 1