page_title: Battle of the Crater
section_title: Mine construction
hierarchical_section_title: Battle of the Crater / Background / Mine construction
caption_attribution_description: Charcoal sketch depicting Col. Pleasants supervising the mining at Petersburg in preparation for the Battle of the Crater. Title inscribed below image. Note: Inscribed on an attached piece of cream paper: Carrying powder into the mine. The soldiers detailed for this duty carried the power--a keg in either end of a grain bag thrown across the shoulder. A portion of the covered way' along which they had to pass, was exposed to the enemies fire. At the dangerous points they would watch their oppartunity[sic] and dash over the exposed ground into comparative safety. Published in: Harpers Weekly, 20 August 1864, p. 528 (cover). Info from LOC: TITLE: Within the mine. Col. Pleasants superinting [sic] the arrival of powder CALL NUMBER: DRWG/US - Waud, no. 447 (A size) [P&amp;P] REPRODUCTION NUMBER: LC-USC4-12564 (color film copy transparency) LC-USZ62-14653 (b&amp;w film copy neg.) No known restrictions on publication. CREATED/PUBLISHED: [] CREATOR: Waud, Alfred R. (Alfred Rudolph), 1828-1891, artist. NOTES: Signed lower right: AR. Waud. Gift, J.P. Morgan, 1919 (DLC/PP-1919:R1.2.447) Reference print available in the Civil War Drawings file -- 1864. Forms part of: Civil War drawing collection.
context_page_description: The Battle of the Crater was a battle of the American Civil War, part of the Siege of Petersburg. It took place on July 30, 1864, between the Confederate Army of Northern Virginia, commanded by General Robert E. Lee, and the Union Army of the Potomac, commanded by Maj. Gen. George G. Meade.
  After weeks of preparation, on July 30, Union forces exploded a mine in Maj. Gen. Ambrose E. Burnside's IX Corps sector, blowing a gap in the Confederate defenses of Petersburg, Virginia. From that propitious beginning, everything deteriorated rapidly for the Union attackers. Unit after unit charged into and around the crater, where soldiers milled in confusion. Grant considered the assault "the saddest affair I have witnessed in this war."
  The Confederates quickly recovered and launched several counterattacks led by Brig. Gen. William Mahone. The breach was sealed off, and Union forces were repulsed with severe casualties. Brig. Gen. Edward Ferrero's division of black soldiers were badly mauled. It may have been Grant's best chance to end the Siege of Petersburg. Instead, the soldiers settled in for another eight months of trench warfare.
context_section_description: Digging began in late June, but even Grant and Meade saw the operation as a "mere way to keep the men occupied" and doubted it of any actual tactical value. They quickly lost interest, and Pleasants soon found himself with few materials for his project, and his men even had to forage for wood to support the structure.
  Work progressed steadily, however. Earth was removed by hand and packed into improvised sledges made from cracker boxes fitted with handles, and the floor, wall, and ceiling of the mine were shored up with timbers from an abandoned wood mill and even from tearing down an old bridge.
  The shaft was elevated as it moved toward the Confederate lines to make sure moisture did not clog up the mine, and fresh air was drawn in by an ingenious air-exchange mechanism near the entrance. A canvas partition isolated the miners' air supply from outside air and allowed miners to enter and exit the work area easily. The miners had constructed a vertical exhaust shaft located well behind Union lines. At the vertical shaft's base, a fire was kept continuously burning. A wooden duct ran the entire length of the tunnel and protruded into the outside air. The fire heated stale air inside of the tunnel, drawing it up the exhaust shaft and out of the mine by the chimney effect. The resulting vacuum then sucked fresh air in from the mine entrance via the wooden duct, which carried it down the length of the tunnel to the place in which the miners were working. That avoided the need for additional ventilation shafts, which could have been observed by the enemy, and it also easily disguised the diggers' progress.
  On July 17, the main shaft reached under the Confederate position. Rumors of a mine construction soon reached the Confederates, but Lee refused to believe or act upon them for two weeks before he commenced countermining attempts, which were sluggish and uncoordinated, and were unable to discover the mine. However, General John Pegram, whose batteries would be above the explosion, took the threat seriously enough to build a new line of trenches and artillery points behind his position as a precaution.
  The mine was in a "T"-shape. The approach shaft was 511 feet (156 m) long, starting in a sunken area downhill and more than 50 feet (15 m) below the Confederate battery, making detection difficult. The tunnel entrance was narrow, about 3 feet (1 m) wide and 4.5 feet (1.4 m) high. At its end, a perpendicular gallery of 75 feet (23 m) extended in both directions. Grant and Meade suddenly decided to use the mine three days after it was completed after a failed attack known later as the First Battle of Deep Bottom. Union soldiers filled the mine with 320 kegs of gunpowder, totaling 8,000 pounds (3,600 kg). The explosives were approximately 20 feet (6 m) under the Confederate works, and the T-gap was packed shut with 11 feet (3 m) of earth in the side galleries. A further 32 feet (10 m) of packed earth in the main gallery to prevent the explosion blasting out the mouth of the mine. On July 28, the powder charges were armed.
caption: Contemporary sketch of Col. Pleasants supervising the placement of powder in the mine
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