Also known as: Thomas Jackson Rodman.
| Service | United States Army Ordnance Department |
|---|---|
| Innovation | Hollow casting with interior cooling of large iron guns |
| Experiments begun | 1844 |
| Landmark gun | 20-inch Rodman, firing a solid shot of over 1,000 pounds |
The Rodman process
In 1844 Lieutenant Thomas Jackson Rodman, then only three years out of the military academy, began a long series of experiments aimed at the central difficulty in casting very large iron cannon: the internal stresses that set a practical limit on gun size. His solution cast the gun hollow around a water-cooled core, so the metal solidified from the inside outward and set the interior in compression.
The method produced iron guns of unprecedented size and strength. Its ultimate expression was the 20-inch Rodman, one of the largest muzzle-loaders ever built, which fired a solid shot of over 1,000 pounds. Rodman smoothbore columbiads served in the heavy and seacoast batteries of the war.
On this site
Sources & further reading
- Melton, Jack W., Jr. Civil War Artillery Projectiles: The Half Shell Book. Blue Ridge, GA: Historical Publications LLC, 2018.
- CivilWarArtillery.com research archive: inventor biographies, manuals, reports, and patent files.