Model 1874 Gatling Gun

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The Model 1874 Gatling gun, sometime known as the Camel Gun, was a much lighter gun than had been made previously. This gun could be carried on pack horses, and fired from a tripod mount, or as one famous advertising engraving showed, from the back of a camel, which gave it the nickname. It is unlikely, however, if the gun was ever used from this mount. This page illustrates the new lock mechanism patented by Richard Gatling in 1872. Links are provided to more information on some of the more successful ammunition hopper mechanisms.

Animation of 1874 model Gatling Gun [G6]

The short 10-barrel Gatling gun of 1874, sometimes referred to as the Camel Gun, was designed to be light enough to be transported on pack horse, or man-ported (or even by camel) and fired from a tripod, cart (or camel). It weighed 135 lbs (61.2 kg). The gun incorporated several features to reduce weight. Barrel lengths were reduced to 18 inches. The lock cylinder and carrier blocks were cast hollow, and much use was made of brass rather than iron. The key feature was the design of the locks, which had been patented two years before (U.S. Patent No. 125563, dated 9 April 1872). The operation of this lock is the main purpose of this page and animation.

In previous designs, the locks, one for each barrel, had been driven forward and pulled back by inclined ramps or cams. The firing pin had been cocked by another cam positioned towards the front of the lock chamber. This is illustrated in the animation for the 1865 model. The locks themselves were quite long.

Gatling's 1872 patent introduced a lock design that was significantly shorter, and which therefore required a shorter casing, and thus reduced the weight of the gun. The firing pin runs through the body of the lock, and is fired by pulling back on the knob at the rear of the pin, and then releasing it at the appropriate moment.

The lock forward and backward motion is now caused by a lug at the rear of the lock, which rides within 'racetrack' cams that are cast or machined into a stationary part of the gun. A spring loaded detaining cam is then positioned to capture the firing pin knob. As the assembly continues to rotate, the lock is driven further forwards by the cam tracks, but the firing pin is held back by the Detaining cam and then released to fire the cartridge.

When the gun is in action, there are always five cartridges going through the process of loading, and five in the process of being extracted and these several operations are continuous while the gun is being worked. Thus as long as the gun is being fed with cartridges the several operations of loading, firing and extracting are carried on automatically, uniformly and continuously. [G6].

Naming the parts

Exploded view of short 1874 gatling with named parts

The Detaining Cam

One of the problems of the early Gatling gun designs that used cocking cams with a significant step, as shown in the 1865 animation, is that if the crank handle were to be turned the wrong way, the tenon on the lock would jam against the step in the cam, and potentially damage either the lock or the cam. Furthermore, if a lock was damaged, or the firing pin broke, the whole gun would have to be disassembled.

Detaining Cam Action

The new shorter lock design used in the short 1874 gun was particularly vulnerable to damage to the knob on the end of the firing pin should the handle be turned the wrong way. For this reason, Gatling designed the Detaining cam so that it was spring loaded. With the gun turning in the correct direction, the knobs are captured as they pass and released to fire at a given point. However, if the gun is turned in the wrong direction, the knob on the lock will push the Detaining cam rearwards. A short animation shows this action.

Another innovation included in the 1874 gun is the lock extractor, which was patented in U.S. Patent No.112138, dated 28 Feb 1871. The crank is turned until markings on the barrel assembly line up with an arrow on the casing. The lock extractor is then turned 90 degrees to unlock it, and it then can be pulled back, bringing with it one of the locks. The locks can then be replaced or repaired without dismantling the gun, and this can be done in the field. The gun can still be operated with the remaining locks.

Ammunition

Gatling guns were chambered for a wide range of ammunition, with overseas customers requiring their purchases to be able to fire the locally-made cartridges. The dimensions of the cartridge shown in the animation are taken from the 1872 patent and show a cartridge with a pronounced shoulder, but in practice the guns would have fired the United States issue 45-70-500 cartridge (.45 inch calibre, 70 grains of black powder, lead bullet weight 500 grains). The animation shows the Broadwell drum magazine, which contained 16 columns of 15 cartridges. The Broadwell drum and other improved magazines are described on the Magazines page.

The Long 1874 model Gatling gun

Gatling also made an 1874 model gun that had 10 32inch barrels and was mounted on an artillery carriage. It is interesting that an illustration of the component parts of this model (G1) show a lock very similar to the 1865 model, this is with a cocking lug cut into the length of the lock, rather than the short lock illustrated above for the short model. Further confusion arises where (G1) shows the firing cycle for an 1871 model Gatling gun using the short lock design that was patented in April 1872. However, it must be recognised that Patent drawings represent ideas and patent drawings rarely translate into an actual gun. The actual guns as built would combine ideas from previous patents as well as practical engineering experience.

Aiming and Scattering.

With the Broadwell drum magazine blocking the centreline view, the 1874 guns used a fixed sight at the front of the right-hand frame, and an adjustable tangent sight at the rear of that side. By adjusting the tangent sight's height, the gun could fire to different ranges.

As an illustration, the following range table shows the gun elevation for various ranges. Note that these tables are for the British .45 cartridge with an 85 grain charge and 480 grain bullet, and fired from a 32 inch barrel. The 45-70-500 cartridge fired from a shorter 18 inch barrel would have had different range - elevation characteristics.

Range (yards)	100	200	300	400	500
Elevation	9 mins	20 mins	33 mins	48 mins	1 deg 4 mins
Range (yards)	800	1000	1500	2000	2400
Elevation	1 deg 54 mins	2 deg 34 mins	4 deg 25 mins	6 deg 32 mins	8 deg 23 mins

The short Model 1874 gun mounted on a tripod (or camel) could easily be aimed and trained to cover a wide front if desired. However, once mounted on an artillery carriage the gun was much more constrained. A training mechanism would be needed. Furthermore the hail of fire put down by a Gatling needed to be distributed across a front. Gatling introduced automatic scattering mechanisms, which automatically adjusted the point of aim as the crank handle was turned. These scattering mechanisms will be described in a separate page.

Engraving of the Short 1874 Gatling Gun on a tripod mount

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If you are unable to view this Quicktime movie, click here to view the animation on YouTube