Emilio describes appoaching climax of the Ft. Wagner siege ( [BBR] pp.116-119):

With our capture of the ridge on the 26th the last natural cover was attained. Beyond for two hundred yards stretched a strip of sand over which the besiegers must advance. It seemed impossible to progress far, as each attempt to do so resulted in severe losses. Every detail at the front maintained its position only at the cost of life. So numerous were the dead at this period of the siege that at almost any hour throughout the day the sound of funeral music could be heard in the camps. Such was the depressing effect upon the men that finally orders were issued to dispense with music at burials. The troops were dispirited by such losses without adequate results. That the strain was great was manifested by an enormous sick list. It was the opinion of experienced officers that the losses by casualties and sickness were greater than might be expected from another assault.

Success or defeat seemed to hang in the balance. Under no greater difficulties and losses many a siege had been raised. General Gillmore, however, was equal to the emergency. He ordered the fifth parallel enlarged and strengthened, the cover increased, and a line of rifle trench run in front of it. New positions were constructed for the sharpshooters. All his light mortars were moved to the front, and his guns trained on Wagner. A powerful calcium light was arranged to illumine the enemy’s work, that our fire might be continuous and effective. Changes were also made in the regiments furnishing permanent details in the trenches and advanced works, and an important part, requiring courage and constancy, was now assigned to our regiment. It is indicated in the following order: —

MORRIS ISLAND, S. C, Aug. 31,1863.
Special Orders No. 131.

II. The Fifty-fourth Massachusetts Volunteers, Col. M. S. Littlefield, Fourth South Carolina Volunteers, commanding, are hereby detailed for special duty in the trenches under the direction of Maj. T. B. Brooks, A. D. C. and Assistant Engineer. The whole of the available force of the regiment will be divided into four equal reliefs, which will relieve each other at intervals of eight hours each. The first relief will report to Major Brooks at the second parallel at 8 A. M. this day. No other details will be made from the regiment until further orders.

By order of
Captain, and Assistant Adjutant-General.

Major Brooks, in his journal of the siege under date of August 31, thus writes, —

” The Third United States Colored Troops, who have been on fatigue duty in the advance trenches since the 20th inst., were relieved to-day by the Fifty-fourth Massachusetts Volunteers (colored), it being desirable to have older troops for the important and hazardous duty required at this period.”

Throughout the whole siege the First New York Engineers held the post of honor. Their sapping brigades took the lead in the advance trench opening the ground, followed by fatigue details which widened the cut and threw up the enlarged cover. These workers were without arms, but were supported by the guard of the trenches. Upon this fatigue work with the engineers, the Fifty-fourth at once engaged. During the night of the 31st work went on rapidly, as the enemy fired but little. Out of a detail of forty men from the One Hundred and Fourth Pennsylvania, one was killed and six were wounded. One of the guard was killed by a torpedo. A man of Company K, of our regiment, was mortally wounded that night.

Early on September 1 our land batteries opened on Sumter, and the monitors on Wagner. Four arches in the north face of Sumter with platforms and guns were carried away. Lieut. P. S. Michie, United States Engineers, was temporarily in charge of the advance works on the right. Much work was done in strengthening the parapets and revetting the slopes. Our Fifty-fourth detail went out under Lieutenant Higginson that morning, and had one man wounded. Rev. Samuel Harrison, of Pittsfield, Mass., commissioned chaplain of the regiment, arrived that day.

September 2 the land batteries were throwing some few shots at Sumter and more at Wagner. Capt. Jos. Walker, First New York Engineers, started the sap at 7 P. M. in a new direction under heavy fire. Considering that the trench was but eighty yards from Wagner, good progress was made. The sap-roller could not be used, because of torpedoes planted thereabout. Our fire was concentrated upon Wagner on the 3d, to protect sapping. But little success resulted, for the enemy’s sharpshooters on the left enfiladed our trench at from one hundred to three hundred yards. At this time the narrowest development in the whole approach was encountered, — but twenty-five yards; and the least depth of sand, — but two feet. Everywhere torpedoes were found planted, arranged with delicate explosive mechanism. Arrangements were made to use a calcium light at night. From August 19 to this date, when the three regiments serving as guards of the trenches were relieved by fresher troops, their loss aggregated ten per cent of their whole force, mainly from artillery fire.

On the night of the 3d, Wagner fired steadily, and the James Island batteries now and then. Our detail at the front had George Vanderpool killed and Alexander Hunter of the same company — H — wounded. Throughout the 4th we fired at Wagner, and in the afternoon received its last shot in daylight. Captain Walker ran the sap twenty-five feet in the morning before he was compelled to cease.