24 pdr. Coehorn
- Type: 24 pdr. Model 1841 Coehorn Mortar
- Rarity: Common
- Years of Manufacture: 1841 - 1865
- Tube Composition: Bronze (Some C.S. variants are cast in iron)
- Bore Diameter: 5.82 inches
- Standard Powder Charge: 1/2 lbs.
- Projectiles: 16.8 lbs. Round Mortar Shells
- Tube Length: 16.3 inches
- Tube Weight: 164 lbs.
- Overall Weight: 296 lbs.
- Range (at 45°): 1,200 yards
- Invented By: Dutch inventor, Baron van Menno Coehoorn
- Special Notes: Photos at right are cropped from a larger photo from the Library of Congress: Broadway Landing, Va. Federal ordnance at the depot, 1865.
The Coehorn mortar, a small muzzle-loading mortar, caliber generally 5.82 inches, is named for it's Dutch inventor, Barron Menno van Coehorn (1641-1704). Mounted on a block or platform, it was portable, easily adjusted, took little powder, and was particularly effective in sieges. The US Army had a 24-pounder brass Coehorn that weighed 164 pounds, or 296 pounds when mounted on it's four-handled oak mortar bed. Two men could move this mortar, but four men could better maneuver and rush this mortar into position in unprepared locations. Explosive shells could be lobbed into masked targets from 50 to 1,200 yards with the Coehorn.
Although the Model 1841 24 pdr. Coehorn is the most widely used on the Union side, the Confederate army did cast and use Iron 12 pdr. Coehorns, with a bore of 4.62 inches, as well as Iron 24 pdrs. As the war progressed, trench warefare became quite common, and mortars were found to be increasingly useful.