Editing Rodman gun (section)

== Use ==

Rodman guns saw little action during [[American Civil War|the Civil War]]. Two 10-inch [[columbiad]]s were used in 1864 and 1865 in Union operations against [[Fort Sumter]].<ref>Suter 1891, p. 117</ref> It seems likely, due to the time period in which they were used, that these were Rodman guns rather than earlier model columbiads. Other reports of the use of 8-inch and 10-inch columbiads may refer to Rodman guns. The 15-inch Rodman guns were never fired in anger;<ref>Birkhimer 1884, p. 291, fn</ref> however, they were widely deployed in [[Seacoast defense in the United States|coast defense]] until replaced by [[Board of Fortifications|Endicott Period]] fortifications in 1895–1905. Some Rodmans of various sizes, along with Parrott rifles, were deployed shortly after the outbreak of the [[Spanish–American War]] in 1898 as a stopgap; it was feared the Spanish fleet would bombard the US east coast.<ref name=ComRep1>[https://books.google.com/books?id=RUtZAAAAIAAJ&dq=submarine+mine+kennebec&pg=PA3780 Congressional serial set, 1900, ''Report of the Commission on the Conduct of the War with Spain'', Vol. 7, pp. 3778–3780, Washington: Government Printing Office]</ref>

The 20-inch Rodmans were only fired eight times in practice<ref>Ripley 1984, p. 80</ref> to determine the effect of the {{cvt|1080|lb|kg|adj=on}} projectiles. It was nearly impossible to find a target that would leave enough evidence to measure the effect of hits. The first four shots were fired with charges of 50, 75, 100, and {{cvt|125|lb|kg}} of [[gunpowder]], reaching a bore pressure of {{cvt|25000|psi}}. Four more shots were fired in March 1867 with charges of 125, 150, 175, and {{cvt|200|lb|kg}} throwing the projectile {{cvt|8000|yd|km}} with the barrel elevated to 25 degrees.<ref>{{cite book |last=Miller |first=Francis Trevelyan |title =The Photographic History of The Civil War |publisher =Castle Books |volume =Five: Forts and Artillery |date =1957 |location =New York |page =137 }}</ref>

=== Rifled versions ===
[[file:Knox8inchConvRifle01.jpg|thumb|250px|8-inch converted rifle, lined down from 10-inch smoothbore]]

During the War, and immediately after, attempts were made to cast [[rifling|rifled]] Rodman guns. Unsuccessful attempts were made to cast a 12-inch rifle in 1861, an 8-inch rifle in 1862, and another 12-inch rifle in 1868.<ref>Birkhimer 1884, p. 267</ref> However, [[Robert Parker Parrott]] at the Cold Spring Foundry, across the Hudson River from the United States Army Military Academy at West Point, used the Rodman water core method of casting to produce large-bore rifled guns in 200- and 300-pound models. [[Parrott rifles]] that had been cast using the Rodman method were inscribed with the initials WC in order to differentiate those guns from ones that had been cast using ordinary methods. Primarily these guns were used on naval vessels, especially large monitors.
In the 1870s and 1880s, efforts focused on converting existing Rodman guns into rifles. 10-inch Rodman smoothbore guns were converted into 8-inch rifles. The first method used was inserting a wrought iron rifle sleeve through the muzzle; a similar steel sleeve was also used later. The last method involved drilling and [[Tap and die|tapping]] the breech of the 10-inch Rodman and inserting a rifled steel sleeve and screwing it in tight with a threaded breech plug. These breech-inserted guns are easily recognized by the square cascabel  which was designed to provide purchase for screwing the breech plug and liner securely into the gun.

These conversions were not viewed favorably and were primarily seen as cheap stopgaps until modern [[breech-loading]] rifles could be developed and emplaced.<ref>Birkhimer 1884, p. 293</ref> However, the 8-inch converted rifle was widely deployed in fortifications constructed in the 1870s, and remained in service until 1905.

=== Confederate copies ===

In 1859 [[Joseph R. Anderson]] of the [[Tredegar Iron Works]] in [[Richmond, Virginia]], and [[Junius L. Archer]] of the [[Bellona Foundry]] in [[Midlothian, Virginia]] (the only two gun foundries then operating in what would become the [[Confederate States of America|Confederacy]]), failed to adopt the Rodman technique of hollow casting, and as result the US Army cancelled contracts with both firms for casting columbiads. Therefore, at the outbreak of the war, southern foundries were not capable of casting guns using the Rodman method.<ref>Daniel & Gunter 1977, p. vii</ref>

The Confederates used solid cast 8-inch and 10-inch columbiads that resemble Rodman guns. A closer examination of these Confederate columbiads reveals that they have a straighter cylindrical contour between the trunnions and the breech as opposed to the sweeping continuous curve of the Rodman gun. The Confederate columbiads have longer [[trunnion]]s that were intended for use with heavy wooden carriages. The Union gun were designed to be mounted in iron carriages with thinner cheeks, permitting shorter trunnions. The exteriors of the Confederate columbiads are rough, not having been finished on a lathe as were their Union counterparts.

On November 14, 1864, and February 20, 1865, at the Tredegar Iron Works, Anderson cast two 12-inch columbiads using the Rodman method. The guns were made too late and were never finished or mounted.<ref>Daniel & Gunter 1977, pp. vii, 103, 104</ref>