Let me resume discussion of 6-pdr field guns, picking up from the earlier post about guns from the colonial and revolutionary period. At the close of the War of 1812, the U.S. Army had on hand a wide array of cannons, both in terms of caliber, design, and origin. Gun-making at that time had emerged from an “art” to a “science.” In Europe, all combatants in the Napoleonic era adopted “systems” of artillery which standardized calibers, gun forms, ammunition sizes, carriages, implements, and other associated equipment. And the Americans would soon follow suit.
While Europeans preferred bronze for field pieces, at least in those early decades of the 19th century, the Americans opted for iron. Lacking large sources of copper or tin (which were discovered later as the new nation expanded), Americans opted to use the very plentiful iron ore. Therefore this period of American gun-making is often known as the “iron age.” Cheaper and harder than bronze, iron had some technical advantages. But at the same time brittle iron required careful construction and casting (which somewhat negated the price advantage over bronze!). There in lay the problem facing American gun-makers and ordnance officers, essentially right up to the eve of the Civil War. And since the 6-pdr guns were the backbone of the field artillery, the type history reveals many of the solutions offered to address the problem.
During the twenty-five years after the last war with Britain, American foundries produced several series and a few experimental batches of cast iron 6-pdr guns. These met with varying degrees of success, but none completely satisfied the Army’s performance requirements.
Columbia Foundry produced at least 40 (probably more) 6-pdr field guns sometime in 1815-1820. These followed the patterns established in the 18th century for the most part. Two of these are on display today at Fort Niagara, New York. These guns lacked rimbases attaching the trunnions to the gun, and retained the vent field ring of earlier forms. (I refer to these by the completely arbitrary designation “Pattern of 1815″)
Bellona Foundry (then known as John Clarke & Co.) produced 122 in 1820-21. These guns continued to follow the older forms. Today one of those guns is identified, and only tentatively at that, on display in Batavia, New York. (I refer to these with another arbitrary designation – Bellona Pattern of 1820.)
With the establishment of a “system of artillery” in 1819, the Ordnance Department provided drawings to the McClurg Foundry (later Fort Pitt Foundry) in Pittsburgh with a contract for 100 guns. McClurg delivered 74 in 1821-22, with an unknown number rejected. These “Model 1819″ are often identified by the nickname “Walking Sticks” due to their slim appearance accentuated by their length. Measuring 66 inches from breech to muzzle, these were longer than any regulation 6-pdrs. The guns weighed 742 pounds.
The “Walking Sticks” foreshadowed the later simplified exterior forms with only a base ring, reinforce shoulder and rather abrupt muzzle swell interrupting an otherwise smooth design. The Model 1819 introduced rimbases to strengthen the trunnions.
The vent of the “Walking Sticks” retained a key-hole shaped pan, indicating the use of matches when firing.
The “Walking Sticks” are perhaps the oldest 6-pdrs which have at least a reasonable claim to be “Civil War Guns.” A plaque fixed to one example at Chickamauga indicates the gun was “captured and recaptured” during the September 1863 battle.
But the weakness of the design lay in the diameter of the breech – a scant 10-inches for the base ring. With such little iron around the chamber, the “sticks” tended to burst. In response, McClurg produced another 90 guns to a revised design. The overall length dropped to 51 inches, with the base ring diameter increased to 11 inches. These new guns weighed 776 pounds. I’ve not seen the guns, but some describe them as “fat” compared to the “Walking Sticks.” (Some references consider these 6-pdr Model or Pattern 1827 field guns)
Columbia Foundry (Washington, D.C.) offered two experimental guns in 1833 which increased weight to 906 pounds. Both guns failed proofing. Following that setback, Columbia produced three 6-pdrs for an “experimental battery.” After successful tests, the Army ordered forty more. One of those sits in a casemate at Fort Pulaski, Georgia today. The form revived both the vent field ring and chase ring of older patterns. But note the addition of a lock-piece block over the vent. The new form is known as Model or Pattern of 1834.
The gun measured 52 inches from base ring to muzzle and weighed 845 pounds. The base ring measured 11.4 inches in diameter. Later Penn Foundry (was McClurg, and of course later Fort Pitt… you got to keep up with the names here!) in Pittsburgh produced 113 more of this Model. The Army rejected at least 22 of the lot in proofing. The remainder suffered from the same lack of endurance of the earlier iron guns.
Thus far the Army’s ordnance officers focused on the breech thickness and exterior form. In 1834 the Army asked West Point Foundry to produce four bronze 6-pdrs for testing. Three of the lot exhibited casting flaws and cavities, a common problem with bronze. Later in 1835 the Army asked West Point to try their hand at cast iron guns, calling for two “long” and two “short” 6-pdrs. This set also failed to meet expectations.
So over twenty-five years, four gun-makers delivered just under 500 iron guns in at least seven patterns. Yet the iron guns failed to meet endurance expectations. While the early “Walking Sticks” certainly lacked sufficient metal at the breech, the chief problem with the later guns lay with the metal. In the 1830s the foundries switched to hot-blast furnaces. Only in the 1840s did Lieutenant Louis A. de Barth determine this technique resulted in low tensile strength guns. But long before the Ordnance Department called for the use of cold-blast furnaces, the Army switched 6-pdr production to bronze.
I’ll look at the first of those “bronze age” guns next.
Aside from on site notes and links provided above, sources consulted for this post were:
Birkhimer, William, Historical Sketch of the Organization, Administration, Material and Tactics of the Artillery, United States Army. Washington: James J. Chapman, 1884. Particularly pages 275-9 discussing the evolution of the American systems of artillery.
Hazlett, James C., Edwin Olmstead, and M. Hume Parks. Field Artillery Weapons of the Civil War, Revised Edition. Urbana and Chicago: University of Illinois Press, 2004.
Ripley, Warren. Artillery and Ammunition of the Civil War, 4th Edition. Charleston, S.C.: The Battery Press, 1984.