Artillery of the Northern States
Colonel Bomford, of the United States ordnance department, invented a cannon called the columbiad, a long - chambered piece for projecting solid shot and shell with a heavy charge of powder, in 1812. The West Point foundry established under special patronage of the government in 1817. The Dahlgren gun, of iron, cast solid and cooled from the exterior, very thick at breech and diminishing to muzzle; first cast, May, 1850. The Rodman gun, a columbiad model, smooth -bore, made by the Rodman process of hollow casting, cooled from the interior; adopted by the United States for all sea-coast cannon, 1860. The first 10-lb. Parrot gun, of iron, cast hollow, cooled from the inside and strengthened by an exterior tube made of wrought-iron bars spirally coiled and shrunk on; made at the West Point foundry in 1860.
McClellan was called to Washington and placed in command, and immediately, by his great energy, tact, and professional skill, restored confidence. On his assuming command of the Military Division of the Potomac, the field-artillery of the division consisted of no more than parts of nine batteries, or thirty pieces of various and, in some instances, unusual and unserviceable calibers. Calculations were made for an expansion of this force, based on an estimated strength of the new Army of the Potomac, about to be formed, of one hundred thousand infantry. Considerations involving the peculiar character and extent of the force to be employed, the probable field and character of the operations, and the limits imposed by the as yet undeveloped resources of the nation, led to the adoption, by General McClellan, of certain recommendations that were made to him by General W. F. Barry, his chief of artillery.
The most important of these were: to have, if possible, three guns for each thousand men; one-third of the guns to be rifled and either Parrott or Ordnance Department guns; batteries to be of not less than four nor more than six guns, and then followed a number of important recommendations concerning the tactical organization of the arm. A variety of unexpected circumstances compelled some slight modifications in these propositions, but in the main they formed the basis of the organization of the artillery of the Army of the Potomac. The supply of ordnance matériel before the Civil War was in large measure obtained from private arsenals and foundries. This sudden expansion in the artillery arm of the country overtaxed these sources of supply, and the Ordnance Department promptly met the requisitions of the chief of artillery of the Army of the Potomac by enlarging, as far as possible, their own arsenals and armories. The use of contract work was in some instances the cause of the introduction of faulty matériel.
The field-guns were of two kinds—the 3-inch wrought-iron (10-pounder) rifle and the smooth-bore Napoleon 12- pounder. The first was made by wrapping boiler-plate around an iron bar to form a rough cylinder, welding it together, and then boring it out and shaping it up. The second was gen- erally made of bronze, cast solid, then bored and prepared. For short ranges in rough country, the Napoleon gun was preferred to the rifle, as it carried heavier charges and the use of canister in it was more effective.
The siege-guns, in which mobility was less important, were of cast iron. Owing to the length of bore and the relatively small diameter, these guns were also usually cast solid. One of these pieces, the Parrott, was strengthened by a wrought-iron cylinder shrunk over the breech.
Sea-coast guns were generally of cast iron, and the best types were cast hollow and cooled by the Rodman process of playing a stream of water on the interior of the tube while the exterior was kept hot, thus regulating the crystallization of the iron and increasing its durability. To some of the sea-coast guns the Parrott principle of construction was applied.
For centuries guns were made of single-piece forgings and castings, and during those centuries there was naturally very little advance in gun construction. The evolution of the one-piece gun to the built-up steel type took place during the Civil War. Captain Rodman, U S. A., succeeded in making cast iron guns in one piece, 20-inch bore, weighing 117,000 pounds. They threw shells weighing 1048 pounds 8000 yards. He accomplished this by cooling the interior of the gun with water circulation before it had cooled. Thus initial tension was produced on the interior parts. The classic researches of Poisson, Barlow and Lame on the behavior of small particles of metal within thick cylinders showed that the stress was maximum at the least radius, and that, passing a certain point, additional metal accomplished nothing. The famous Parrott rifles (West Point foundry) recognized this truth by shrinking a wrought iron band upon the cast iron breech of the gun, which was also cooled on Rodman's principle. Captain Brooke, U.S.A., followed the same practice.
When the army took the field, in March, 1862, the light artillery consisted of ninety-two batteries of five hundred and twenty guns, twelve thousand five hundred men, and eleven thousand horses, all fully equipped and in readiness for field- service. Of this force, thirty batteries were regular and sixty-two volunteer.
The prevailing impression in England was that in cannon, as in other matters, America eclipsed others when it comes to mere size. No doubt bigger guns have been made in America than elsewhere — but the big guns were smooth bores. The largest gun is a 50-ton 20-inch gun, and designed to carry a charge of 1001b. of powder, with a round shot. It was reserved for America to regard weight so lightly as to produce a gun weighing 50 tons, and yet of hardly greater power as a smooth bore than the British 22-ton gun, which can besides throw rifled projectiles. As to n'fled guns the Northern States had a considerable number of Parrot guns. These were nothing more or less than the hooped wrought iron gun with which all Europe was familiar.
At times, big mortars were used for siege purposes, although their great weight — 17,000 pounds — made them difficult to emplace in temporary works. At Petersburg, an interesting experiment was tried which resulted successfully. A large 13-inch Coehorn mortar was mounted on an ordinary railroad platform car, run down to a point within range of the Confederate works, and halted on a curve so that by a slight movement of the car the direction of the piece could be changed. The mortar, fired with fourteen pounds of powder, recoiled less than two feet on the car, which, in turn, was moved only ten or twelve feet on the track. The firing excited much apprehension in the Confederate works, and was effective in preventing their batteries from enfilading the right of the Union lines.
William P. Brady's Civil War Pictures contain several excellent photographs of two designs of artillery that were used by the Union Army in their siege of Petersburg in 1864. One of these guns, plates 2 and 2A, was a 13-inch muzzle-loading mortar, 2.7 calibers in length. This mortar weighed 17,000 pounds, used a spherical shell weighing 220 pounds, apd a powder charge of 20 pounds. The records available indicate that this mortar had a range between 3 and 4 miles and did effective work in the siege. It will be noted that the car on which the mortar is mounted seems to be made up of two standard trucks on which an improvised platform has been placed. It is understood that this carriage failed after the mortar had been fired several times and that thereafter the practice was to transfer the mortar and its platform from the railway car to a more solid foundation. This railway mount was called "The Dictator" and "Petersburg Express".
In Professional Papers, Corps of Engineers, No. 14, Siege Artillery in the Campaign Against Richmond, by Bvt. Brig. Gen. Henry L. Abbott, United States Army, 1868 (5), referring to the campaign of 1864: "The mortar fired with 14 pounds of powder, recoiled less than 2 feet on the car, which moved 10 or 12 feet on the track. The effect of the charge was taken up without damage to the axles, even when the full allowance of 20 pounds of powder wap used. This mortar, whose shell would crush and explode any ordinary field magazine, excited dread among the Confederate gunners, and was effective in inducing their enfilading batteries on Chesterfield Heights to discontinue fire upon the right of our line. Its practice was excellent. At the Battle of the Mine, as reported by three different observers stationed at different points, the explosion of one of its shells blew a Confederate field gun and carriage above the parapet at a range of about 3,600 yards."
The fact that Gen. Abbott mentions that this mortar which operated against Richmond was mounted on a standard flat car seems to indicate that it is not the same mortar that was photo- graphed by Brady at Petersburg. The mortar carriage was apparently improvised, the two trucks being practically together.
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