The Gatling Gun
Hartford, June 15th, 1877
My Dear Friend.
It may be interesting to you to know how I came to invent the gun which bears my name; I will tell you: In 1861, during the opening events of the war, (residing at that time in Indianapolis, Ind.,) I witnessed almost daily the departure of troops to the front and the return of the wounded, sick, and dead. The most of the latter lost their lives, not in battle, but by sickness and exposure incident to the service. It occurred to me if I could invent a machine--a gun-- which could by its rapidity of fire, enable one man to do as much battle duty as a hundred, that it would, to a great extent, supersede the necessity of large armies, and consequently, exposure to battle and disease be greatly diminished. I thought over the subject and finally this idea took practical form in the invention of the Gatling Gun.
Yours truly,
R.J. Gatling
The Gatling gun is one of the best-known early rapid-fire weapons and a forerunner of the modern machine gun. Invented by Richard Gatling, it is known for its use by the Union forces during the American Civil War in the 1860s, which was the first time it was employed in combat. Later it was used in the Boshin War, the Anglo-Zulu War and still later in the assault on San Juan Hill during the Spanish-American War.
The Gatling gun's operation centered on a cyclic multi-barrel design which facilitated cooling and synchronized the firing/reloading sequence. Each barrel fired a single shot when it reached a certain point in the cycle, after which it ejected the spent cartridge, loaded a new round, and in the process, cooled down somewhat. This configuration allowed higher rates of fire to be achieved without the barrel overheating.
History
The Gatling gun was designed by the American inventor Dr. Richard J. Gatling in 1861 and patented on November 4, 1862. Gatling wrote that he created it to reduce the size of armies and so reduce the number of deaths by combat and disease, and to show how futile war is.
Although the first Gatling gun was capable of firing continuously, it required a person to crank it; therefore it was not a true automatic weapon. The Maxim gun, invented in 1884, was the first true fully automatic weapon, making use of the fired projectile's recoil force to reload the weapon. Nonetheless, the Gatling gun represented a huge leap in firearm technology.
Prior to the Gatling gun, the only weapons available to militaries capable of firing many projectiles in a short space of time were mass-firing volley weapons like the French Reffye in 1870–1871, or field cannons firing canister, much like a very large shotgun. The latter were widely used during and after the Napoleonic Wars. Although the maximum rate of fire was increased by firing multiple projectiles simultaneously, these weapons still needed to be reloaded after each discharge, which for multi-barrel systems like the mitrailleuse was cumbersome and time-consuming. This negated much of the advantage of their high rate of fire per discharge, making them much less powerful on the battlefield. In comparison, the Gatling gun offered a rapid and continuous rate of fire without having to manually reload by opening the breech.
The original Gatling gun was a field weapon which used multiple rotating barrels turned by a hand crank, and firing loose (no links or belt) metal cartridge ammunition using a gravity feed system from a hopper. The Gatling gun's innovation lay neither in the rotating chamber mechanism, first used by the Puckle gun nearly a century and a half before, nor in the use of multiple barrels to limit overheating (used by the Mitrailleuse gun); rather, the innovation was the gravity feed reloading system, which allowed unskilled operators to achieve a relatively high rate of fire of 200 rounds per minute.
American Civil War and the Americas
The Gatling gun was first used in warfare during the American Civil War. Two of the guns were employed near Petersburg and eight were fitted on gunboats. The gun was not accepted by the American Army until 1866, but a sales representative of the manufacturing company demonstrated it in combat.
Captain Germán Astete of the Peruvian Navy took with him dozens of Gatling guns from the United States to Peru in December 1879 during the Peru-Chile War of the Pacific. Gatling guns were used by the Peruvian navy and army, especially in the Battle of Tacna (May 1880) and the "Battle of San Juan" (January 1881) against the Chilean army invaders. Lieutenant A.L. Howard of the Connecticut National Guard had an interest in the company manufacturing Gatling guns, and took a personally-owned Gatling gun to Saskatchewan in Canada in 1885 for use with the Canadian military against the Métis during Louis Riel's North-West Rebellion.
Early multi-barrel guns were approximately the size and weight of artillery pieces, and were often perceived as a replacement for cannon firing grapeshot or canister shot. Gatling guns were even mounted aboard ships. Compared with earlier weapons such as the Mitrailleuse, which required manual reloading, the Gatling gun was more reliable and easier to operate, and had a lower, but continuous rate of fire. The large wheels required to move these guns around required a high firing position, which increased the vulnerability of their crews.
Sustained firing of gunpowder cartridges generated a cloud of smoke, making concealment impossible until smokeless powder became available in the late 19th century. When fighting troops of industrialized nations, Gatling guns could be engaged by artillery they could not reach and their crews could be targeted by snipers they could not see.
Basic design
The Gatling gun was hand-crank operated with six barrels revolving around a central shaft, although some models had as many as ten. Early models had a fibrous matting stuffed in among the barrels which could be soaked with water to cool the barrels down. Later models eliminated the matting-filled barrels as being counterproductive.
The ammunition was initially a steel cylinder charged with black powder and primed with a percussion cap, because self-contained brass cartridges had not yet been fully developed and available. The shells were gravity-fed into the breech through a hopper or stick magazine on top of the gun. Each barrel had its own firing mechanism. After 1861, new brass cartridges similar to modern cartridges replaced the paper cartridge, but Gatling did not switch to them immediately.
The Model 1881 was designed to use the 'Bruce'-style feed system (U.S. Patents 247,158 and 343,532) that accepted two rows of .45-70 cartridges. While one row was being fed into the gun, the other could be reloaded, thus allowing sustained fire. The final gun required four operators. By 1876, the gun had a theoretical rate of fire of 1,200 rounds per minute, although 400 rounds per minute was more likely in combat.
Each barrel fires once per revolution at about the same position. The barrels, a carrier, and a lock cylinder were separate and all mounted on a solid plate revolving around a central shaft, mounted on an oblong fixed frame. The carrier was grooved and the lock cylinder was drilled with holes corresponding to the barrels. Each barrel had a single lock, working in the lock cylinder on a line with the barrel. The lock cylinder was encased and joined to the frame. The casing was partitioned, and through this opening the barrel shaft was journaled. In front of the casing was a cam with spiral surfaces. The cam imparted a reciprocating motion to the locks when the gun rotated. Also in the casing was a cocking ring with projections to cock and fire the gun.
Turning the crank rotated the shaft. Cartridges, held in a hopper, dropped individually into the grooves of the carrier. The lock was simultaneously forced by the cam to move forward and load the cartridge, and when the cam was at its highest point, the cocking ring freed the lock and fired the cartridge. After the cartridge was fired the continuing action of the cam drew back the lock bringing with it the spent cartridge which then dropped to the ground.
The grouped barrel concept had been explored by inventors since the 18th century, but poor engineering and the lack of a unitary cartridge made previous designs unsuccessful. The initial Gatling gun design used self-contained, reloadable steel cylinders with a chamber holding a ball and black-powder charge, and a percussion cap on one end. As the barrels rotated, these steel cylinders dropped into place, were fired, and were then ejected from the gun. The innovative features of the Gatling gun were its independent firing mechanism for each barrel and the simultaneous action of the locks, barrels, carrier and breech.
The smallest-caliber gun also had a Broadwell drum feed in place of the curved magazine of the other guns. The drum, named after L. W. Broadwell, an agent for Gatling's company, comprised twenty stick magazines arranged around a central axis, like the spokes of a wheel, each holding twenty cartridges with the bullet noses oriented toward the central axis. This invention was patented in U. S. 110,338. As each magazine emptied, the drum was manually rotated to bring a new magazine into use until all 400 rounds had been fired.
By 1893, the Gatling was adapted to take the new .30 Army smokeless cartridge. The new M1893 guns featured six barrels, and were capable of a maximum (initial) rate of fire of 800–900 rounds per minute. Dr. Gatling later used examples of the M1893 powered by electric motor and belt to drive the crank. Tests demonstrated the electric Gatling could fire bursts of up to 1,500 rpm.
The M1893, with minor revisions, became the M1895, and 94 guns were produced for the U.S. Army by Colt. Four M1895 Gatlings under Lt. John H. Parker saw considerable combat during the Santiago campaign in Cuba in 1898. The M1895 was designed to accept only the Bruce feeder. All previous models were unpainted, but the M1895 was painted olive drab (O.D.) green, with some parts left blued.
The Model 1900 was very similar to the model 1895, but with only a few components finished in O.D. green. The U.S. Army purchased a quantity of M1900s. All Gatling Models 1895–1903 could be mounted on an armored field carriage. In 1903, the Army converted its M1900 guns in .30 Army to fit the new .30-03 cartridge (standardized for the M1903 Springfield rifle) as the M1903. The later M1903-'06 was an M1903 converted to .30-06. This conversion was principally carried out at the Army's Springfield Armory arsenal repair shops. All models of Gatling guns were declared obsolete by the U.S. Army in 1911, after 45 years of service.