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Vietnam era helicopters
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Models 1862-1871
Models 1874-1877
Models 1879-1881
Models 1883-1889
Models 1893-1903
Evolution of M61 Vulcan Gatling Gun
A Gatling Gun for use on helicopters
Phalanx CIWS (Close-In Weapon System)
Gatling Machine Guns indexed by Aircraft Model No.
Note: Most of the information on this page is based on information from The Gatling Gun by Paul F. Wahl and Donald R. Toppel, Arco Publishing Company, New York, NY, 1965.
By the time the Civil War broke-out in April 1861, Richard J. Gatling had already applied for at least 10 patents. In 1835, Richard Gatling invented, but missed a previously patented ship's screw propeller by only a few months. In 1839 he invented a seed-sowing rice planter, later adapted as a very successful wheat drill, which used less seed and increased yield from the hand sowing method in use at the time.
Born September 12, 1818 in Hertford Count, North Carolina, Richard Gatling was the son of a well-to-do planter, Jordan Gatling, who himself had two patents to his credit. At the start of the war, Gatling thought the invention of a high rate of fire automatic gun would reduce the number of soldiers required to man the battlefield, reducing their exposure to disease and other hazards of war.
In 1870, Richard Gatling moved his family to Hartford, Connecticut where the Gatling gun was manufactured at the Colt Armory. The Gatling's lived in Hartford until 1897 when the family moved to New York City to be near their daughter and her husband.
Richard Gatling pursued and promoted many new inventions until he died in February 1903, at the age of 84. His most successful inventions, the Gatling gun and his wheat drill, made him a fortune which he largely lost in unwise investments in railroads, real estate, and in promotion of his other inventions, but when he died he was still a wealthy man. In 1943, during World War II, the U.S. Government named a new destroyer the USS Gatling, in honor of the service he performed to his country.
The Gatling Gun Company remained in Indianapolis, Indiana until 1874, when it was incorporated at Hartford, Connecticut, where the gun was manufactured by Colt. The partnership between Colt and the Gatling Gun Company grew closer and by 1897 the two companies essentially merged. Within a few years Colt Patent Fire Arms Manufacturing Company completely absorbed the Gatling Gun Company. Gatling's European subsidiary had previously been sold to Frederick C. Penfield, of London, England, in 1888.
Model 1862. In 1862, at the age of 44, Richard Gatling had demonstrated
his first working model of the Gatling gun in Indianapolis, Indiana. He patented
the Gatling gun on November 4, 1862. Its key elements were a lock cylinder
containing six strikers which revolved with six gun barrels, powered by a hand
crank. The gun used separate .58 cal. paper cartridges and percussion caps, which
resulted in gas leakage. The model 1862 Gatling gun attained a very high rate of
fire of 200 spm (shots per minute) for that time.
Model 1865. By changing to a unitary cartridge, Gatling overcame the
problem with gas leakage only to encounter problems in the ammunition feed
mechanism. Gatling designed a new breech mechanism which fixed the feed problem,
leading to the development of the much improved model 1865 six-barrel 1 inch
Gatling gun, the forerunner of all later model Gatling guns.Models 1862-1871
Model 1866. After successful trials at Frankford Arsenal and Fort Monroe, the U.S. Army ordered 50 1 inch cal. and 50 .50 cal. model 1866 six-barrel Gatling guns. All but five of the .50 cal. guns were converted to .45 cal. beginning in August 1866. The gun used a simple tin box to hold cartridges. These guns were all fixed-mounted on an artillery carriage.
Model 1871 had improved breech bolts that could be easily removed for maintenance in the field used a new curved cartridge magazine. In 1872 a new hopper design permitted use of a 400 round Broadwell drum. The Broadwell drum was a circular cluster of 20 vertical feed magazines containing 20 cartridges each. When a magazine emptied, the gunner manually turned the drum to align the next full magazine. The U.S. Army purchased one 1 inch cal. and nine .50 cal model 1871 ten-barrel weapons.
Model 1874 featured a shorter, lighter bronze breech that resulted in
a lighter and sturdier .45 cal. gun. The gun had an automatic or manual traversing
mechanism and for the first time, an adjustable set screw which permitted head
space adjustment. A right hand mounting sight permitted the feed hopper to be
shifted from 45° to a vertical feed, using a new box magazine. The guns were made
in two lengths, a musket length and a smaller shorter length "Camel" gun.
This ten-barrel .45 cal. gun had an improved automatic or manual traversing mechanism.
The U.S. Army bought eight musket length guns. The lighter "Camel" gun
could be mounted on a new lighter cavalry cart, tripod, or camel saddle. The
"Camel" name was more a marketing ploy than a practical application. The
U.S. Army bought 11
model 1874 guns.Models 1874-1877
Model 1875 had an improved hopper, new magazine, and a beveled bolt face to correct some jamming problems experienced with the model 1874 gun. A new vertical feed 40 round magazine, trapezoidal in cross-section, was introduced at this time. The U.S. Army bought 44 long barrel and four "Camel" guns.
Model 1876 featured relocation of the hopper to the left of center, cartridge guides, improved breech, and altered breech bolt bevel.
Model 1877 long barrel had a new feed hopper for easier ejection and a higher rate of fire.
Model 1877 "Bulldog" was the first Gatling gun to feature a fully enclosed bronze housing over the barrels and breech. The "Bulldog" was a five-barrel .45 cal. tripod mounted weapon. A few were mounted on a light cavalry cart. A rear mounting hand crank permitted a very high rate of fire of up to 1,000 spm, almost twice the rate of a typical World War II machine gun.
Model 1879 was the first Gatling gun with a flexible mount that could
traverse through an arc like a true machine gun. Head spacing could be adjusted
using a notched adjusting knob without using any tools. Most model 1879 guns were
mounted on artillery carriages, but a few were mounted on tripods. The model 1879
was a ten-barrel .45 cal. fully encased gun using the standard 40 round trapezoidal
magazine. The U.S. Army purchased 32 model 1879 Gatlings.Models 1879-1881
Model 1881 was similar to the model 1879, but had a modified feed hopper to accept the new Bruce feeder. The U.S. Army bought 27 model 1881 guns.
Bruce feeder, named after it's inventor, L.F. Bruce, permitted the Gatling gun to be loaded directly from 20 round cardboard cartons into a two slot vertical bar. When one slot emptied, gravity forced a full slot over the feed hopper. By alternately loading the empty slot, a continuous fire could be sustained. The Bruce feeder was a favorite of the U.S. Army.
Model 1883 was a ten-barrel .45 cal. gun fully encased in a bronze jacket.
A side mounting hand crank produced a rate of fire of up to 800 spm, but could
be rear mounted to increase the rate up to 1,500 spm. Internal components were
strengthened to withstand the punishment from the higher rate of fire. The model
1883 had a new flexible yoke that permitted a wider angle of traverse and elevation
than previous models. However, the vertical feed magazine did not work as well with
wider range in elevation. A new flat donut-shaped Accles mechanical drum feeder was
developed for use with this gun. The standard mount was a heavy steel Army carriage,
but it could also be mounted on a light folding steel tripod. The Accles feeder
was a complex mechanism subject to jamming. In 1898, the U.S. Army refitted it's
model 1883 Gatlings with a Bruce feeder adapter.Models 1883-1889
Models 1885, 1886, and 1887 were modifications to the model 1883 with improvements in the ejector and cartridge guides. The Army purchased 100 model 1885-1887 Gatling guns.
Model 1889 went back to an improved version of the model 1881 that could use either a Bruce feeder or the older style gravity feed magazine. This model featured a heavy steel gunner's shield and ten exposed .45 cal. barrels. The U.S. Army bought 53 model 1889-1892 Gatlings.
Model 1893 was similar to models 1889-1892, but the caliber was changed
to the new Army standard .30/40 cartridge. A new horizontal strip feeder was
introduced with the model 1893. The strip feeder fed from the left side. Wedges
in the hopper stripped each round from its retaining prongs into the hopper. The
empty feeder ejected to the right side. The U.S. Army bought 18 ten-barrel .30 cal.
model 1893 guns. The strip feeder was also subject to jamming. In 1897 the Army
converted all of it's .30 cal. Gatlings to accept the Bruce feeder. In 1893 the
Gatling Gun Company introduced a six-barrel version of the model 1893 that was
the smallest of all the Gatling guns.
Model 1895 was similar to the model 1893, but was designed to accept
only the Bruce feeder. All previous model were unpainted, but this model was
painted olive drab, with some parts blued.
Model 1900 was very similar to the model 1895, but only a few parts
were painted olive drab. Models 1895-1903 could be mounted on an armored field
carriage. The U.S. Army bought 94 model 1895 Gatlings and many model 1900s.
Model 1903. In 1903, the Army converted their model 1900 guns to fit
the .30-03 cartridge that became the Army standard with the introduction of their
new model 1903 Springfield rifle.
Model 1903-06. Later, all model 1903 Gatlings were converted to cal.
.30-06. This conversion was done mostly at the Army's Springfield Armory.
Obsolescence. With a advent of the automatic machine gun, the U.S. Army
declared their Gatling gun obsolete in 1911, after 45 years of service to the
U.S. Army.
Models 1893-1903
World War II fighters and bombers were commonly equipped with Browning M2 heavy
barrel .50 cal. machine guns which had a maximum firing rate of 1,200 spm. The
Gatling gun had exceeded that rate of fire in 1880.
In 1946, U.S. Army Ordnance Research and Development Service engineers dusted-off
the old Gatling principle and adapted it to create the 6,000 spm M61 series Vulcan
20mm Gatling gun that now arms many of our U.S. Air Force and U.S. Navy supersonic
fighters, including the F-14, F-15, F-16, F/A-18 and the F-111A. The Gatling principle
permitted a high rate of fire while reducing heat and barrel erosion.Evolution of the M61 Vulcan Gatling Gun
In June 1946, the General Electric Company was awarded the contract for "Project Vulcan". In 1950, GE delivered ten initial model A .60 cal. T45 guns for evaluation. Thirty-three model C T45 guns were delivered in 1952 in three calibers: .60 cal., 20mm, and 27mm, for additional testing. After extensive testing, the T171 20mm gun was selected for further development. In 1956 the T171 20mm gun was standardized by the U.S. Army and U.S. Air Force as the M61 20mm Vulcan aircraft gun. The M61 20mm Vulcan is an externally powered, six-barrel, rotary-fire gun having a rate of fire of up to 7200 spm. The firing rate is selectable at 4,000 spm or 6,000 spm. The gun fires standard electrically primed 20mm ammunition. The M61A1 is hydraulically or ram-air driven, electrically controlled, and uses a linkless ammunition feed system. The M61A1 is used in the Air Force GAU-8 and the Navy Phalanx CIWS (SeeWiz).
Source material:
The Gatling Gun by Paul F. Wahl and Donald R. Toppel, Arco Publishing
Company, New York, NY, 1965. The Gatling Gun is the best and possibly
only definitive work that has ever been written on the Gatling gun.
The M61 Vulcan was modified into a lighter three-barrel version by removing
three of the barrels, shortening the barrels, and changing the ammunition
feed mechanism. The light weight modified Vulcan was type classified as
the Development of a light Gatling Gun for use on helicopters
Modified
three-barrel M61 Vulcan (M197) door gun on HU-1B "Huey"
M197 20mm door gun on UH-1B "Huey"
M195 20mm automatic gun on XM35 armament subsystem for AH-1G Cobra
M197 20mm automatic gun on AH-1F Modernized Cobra (Copyright
Butch Lottman)
Near the end of the Vietnam war, the XM134 was tested experimentally for use on combat vehicles and as a infantry weapon. These programs were terminated in the early 1970s due to lack of funding.
The Air Force GAU-2B/A (Army M134) 7.62mm
"minigun" was designed to provide a light weight high rate of
fire armament package for use on helicopters and light fixed-wing aircraft. The
basic M61 Vulcan has been simplified and redesigned to fire percussion primed
7.62mm ammunition. The basic M134 can be readily modified to fire other smaller
caliber ammunition, such as the XM214 5.56mm
"mini-minigun". See table below for a
cross-reference to specific armament subsystems.
M134 7.62mm
"minigun"
XM214 5.56mm
"mini-minigun"
Pintle mounted M134 minigun on UH-1H Nighthawk gunship
(Copyright
Mike Austin at
http://www.vietvet.org/bg23.htm)
M134 Minigun firing (viewed thru pilot's window of UH-1M gunship)
(Copyright Butch
Lottman)
Phalanx CIWS (SeeWiz) is a rapid-fire, computer-controlled radar and gun
system to defeat anti-ship missiles, as well as other close-in surface and
air threats. The Phalanx system automatically carries out search, detection,
target acquisition, firing and kill assessment. The system's unique defensive
capability is based on closed-loop spotting, a radar technology breakthrough.
This technique uses advanced radar and computer technology to locate, identify
and direct a stream of Armor Piercing Discarding Sabot (APDS) rounds to the
target. The system uses an electrically-controlled, pneumatically-driven M61A1
Vulcan 20mm six-barrel Gatling-type gun capable of firing at a selectable 3,000
or 4,500 spm rate. Initially deployed in 1979, Phalanx is installed on every U.S.
combatant ship, as well as combatant ships of 16 allied nations (Source:
Phalanx CIWS (Close-In Weapon System)
Phalanx 20mm high rate of fire Close-In Weapon System (Copyright Raytheon Company)
Phalanx video [phalanx.mpg] 258k, 11 sec (Copyright Raytheon Company)
Phalanx video, with sound bit [phalanx.avi] 138k, 2 sec (Video provided by
Robert Maddog Moland)
Gatling Machine Guns indexed by Aircraft
Model No.
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