Autoloader
Encyclopedia
An autoloader or auto-loader is a mechanical aid or replacement for the personnel that load ordnance
into crew-served weapons, such as tank
s and artillery
. The term is generally only applied to larger weapons that would otherwise have a dedicated person or persons loading them; however, semi-automatic firearm
s are sometimes informally called "auto-loaders".
An autoloader, as its name suggests, extracts a shell
and propellant charge from a magazine
, loads it into the chamber
of the gun, and closes the breech
. It can and often does replace the loader. By automating the loading process, it could streamline and speed up the loading process, resulting in a more effective fighting machine. Also, since an autoloader can take up less volume inside a tank than a human, it allows for a lower profile, saving weight and making the tank harder to hit. However, auto-loaders on tanks often fail to live up to these promises and even when they do, they are often to the detriment of other factors that determine combat effectiveness.
. Their first combat use was in tank-buster aircraft such as the 75 mm calibre Bordkanone BK 7,5 cannon-equipped Henschel Hs 129
B-3. Auto-loaders in the modern sense bear the closest similarity to those fitted to aircraft. Every Soviet
- and Russian-derived tank since the T-64
main battle tank
has used an autoloader, allowing a significant decrease of weight and size. Their use has been mostly shunned by American
and British
tanks, although the American T22 medium tank was one of the first to use an autoloader.
In the modern era, autoloading is ubiquitous on any large (3–inch, or 76.2 mm caliber or greater) naval gun. The size of the shells, when combined with the more elaborate autoloading facilities available in the wider spaces of a ship, makes an autoloader much faster than human loaders. For example, the US
5"/38 Mark 12 can load about 20 rounds per minute.
The Soviet/Russia
n AK-130 (twin barrel 130 mm), using autoloading, can achieve up to 40 rounds per barrel per minute.
The Italian
127 mm/5" Compact has similar performance. The largest caliber auto-loading naval rifles were the US 8"/55 Mark 16, deployed on the three cruisers of the Des Moines
class in the late 1940s, and the 8"/55 Mark 71 tested aboard the destroyer USS Hull in the late 1970s. Both weapons achieved a rate of fire of 12 rounds barrel per minute, compared to 3-4 rounds per minute for the preceding hand-loaded weapons.
The advent of jet aircraft, and the rate of fire required to engage them, hastened the adoption of automatic loaders on naval artillery. Development of the loading systems was often problematic, and reliability was seriously compromised in many cases. The US 5"/54 Mark 42 was derated from 40 rounds per minute to 34 to improve reliability. The Soviet/Russian AK-130 was so badly delayed that the missile cruiser Kirov
(later Admiral Ushakov) was forced to use two older weapons in its place. The US 3"/70 Mark 37 actually spent more time in design (13 years) than in service (12 years) due to severe unreliability. These problems are largely of the past; the state of the art has advanced a great deal, and requirements have generally become less aggressive.
On the other hand, the very newest autoloaders claim to match this rate of fire. Furthermore, it is considered atypical to engage more than a few targets per minute in a tank. The autoloader may also have an advantage over rough terrain that may jar the human loader enough to disrupt his loading cycle.
For weapons above 127 mm, the increased weight of the round pushes this issue decisively in favor of the autoloader. For 6-inch self-propelled artillery, for example, autoloaders can typically achieve 8–12 rounds per minute, while humans typically achieve 4 rounds per minute. For sustained bombardments, this may not be so important for sustained firing rates for artillery is typically only 1–2 rounds per minute, but the rapid-fire capability is vital to shoot-and-scoot
tactics to deliver enough fire and then avoid the rapid counterbattery response provided by modern counterbattery systems.
For example the M1 Abrams was designed to protect the crew from cook-off, and this is accomplished by storing the main gun ammunition in a compartment at the rear of the turret, which is separated from the crew by a rapidly power operated armored door, which is only opened for a couple of seconds each time the loader needs to grab another round, and the top of this compartment has special roof panels that are armored against outside attack, but are much less resistant to pressure from inside, so that if this compartment is penetrated by enemy fire, these panels will vent the explosion generated by the ammunition burning, while protecting the crew. Other western designs from the later cold war era to the present with manual loading have similar protective features. In contrast, the Soviet tanks of the Cold War which employ autoloaders store the ammunition on a carousel in the middle of the crew compartment, where any penetration by enemy fire is likely to incinerate the crew and blow the turret right off the top of the tank.
However, some newer autoloader designs also store the ammunition in an isolated compartment in the turret bustle, with blow off panels on top and the ramming mechanism underneath or in the middle. This allows for much better crew protection, but is disadvantaged because the loading mechanism located in the ammunition compartment reduces the available space and number of rounds that can be carried considerably compared to a similar sized compartment without machinery. With such a design, the loader crew member can be eliminated, but only half the ammunition can be carried ready, in the compartment with the autoloader. Therefore, such a tank usually stores additional ammo in compartmentalized storage at the bottom of the fighting compartment, like older manual loading tank designs. This storage can be surrounded by water, and compartmentalized to some extent, but the reduced crew must still transfer this ammunition to the autoloader at some point. However, such a design can also allow for the rapid replacement of the autoloader and reloading of the ready ammunition by making the compartment at the rear of the turret a modular component that can be easily replaced with appropriate support equipment, similar to how the US MLRS system is reloaded, but possibly even faster. Another possible advantage is that the door that separates the turret can only be large enough for one round of ammunition to slide through, rather than extending across the entire rear of the turret as in the case of the M1 Abrams - this could save additional mass and reduce the power necessary to operate the door, by using less massive armor for the same level of protection, since it would be part of the turret instead of a sliding component in a heavy frame.
is an example of this. The current generation of tanks using autoloaders (Russian T-90
, Japanese Type 90, Chinese Type 98
, French Leclerc
) all weigh between 45–55 tons. Tanks that do not use autoloaders tend to weigh in the 55–70 ton range (American M1A2 Abrams
, German Leopard 2
, British Challenger 2).
Ammunition
Ammunition is a generic term derived from the French language la munition which embraced all material used for war , but which in time came to refer specifically to gunpowder and artillery. The collective term for all types of ammunition is munitions...
into crew-served weapons, such as tank
Tank
A tank is a tracked, armoured fighting vehicle designed for front-line combat which combines operational mobility, tactical offensive, and defensive capabilities...
s and artillery
Artillery
Originally applied to any group of infantry primarily armed with projectile weapons, artillery has over time become limited in meaning to refer only to those engines of war that operate by projection of munitions far beyond the range of effect of personal weapons...
. The term is generally only applied to larger weapons that would otherwise have a dedicated person or persons loading them; however, semi-automatic firearm
Semi-automatic firearm
A semi-automatic, or self-loading firearm is a weapon which performs all steps necessary to prepare the weapon to fire again after firing—assuming cartridges remain in the weapon's feed device or magazine...
s are sometimes informally called "auto-loaders".
An autoloader, as its name suggests, extracts a shell
Shell (projectile)
A shell is a payload-carrying projectile, which, as opposed to shot, contains an explosive or other filling, though modern usage sometimes includes large solid projectiles properly termed shot . Solid shot may contain a pyrotechnic compound if a tracer or spotting charge is used...
and propellant charge from a magazine
Magazine (firearm)
A magazine is an ammunition storage and feeding device within or attached to a repeating firearm. Magazines may be integral to the firearm or removable . The magazine functions by moving the cartridges stored in the magazine into a position where they may be loaded into the chamber by the action...
, loads it into the chamber
Chamber (weaponry)
In firearms, the chamber is that portion of the barrel or firing cylinder in which the cartridge is inserted prior to being fired. Rifles and pistols generally have a single chamber in their barrels, while revolvers have multiple chambers in their cylinders and no chamber in their barrel...
of the gun, and closes the breech
Breech-loading weapon
A breech-loading weapon is a firearm in which the cartridge or shell is inserted or loaded into a chamber integral to the rear portion of a barrel....
. It can and often does replace the loader. By automating the loading process, it could streamline and speed up the loading process, resulting in a more effective fighting machine. Also, since an autoloader can take up less volume inside a tank than a human, it allows for a lower profile, saving weight and making the tank harder to hit. However, auto-loaders on tanks often fail to live up to these promises and even when they do, they are often to the detriment of other factors that determine combat effectiveness.
History
Auto-loaders were developed at the beginning of World War IIWorld War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...
. Their first combat use was in tank-buster aircraft such as the 75 mm calibre Bordkanone BK 7,5 cannon-equipped Henschel Hs 129
Henschel Hs 129
The Henschel Hs 129 was a World War II ground-attack aircraft fielded by the German Luftwaffe. Its nickname, the Panzerknacker , is a deliberate pun—in German, it also means "safe cracker"...
B-3. Auto-loaders in the modern sense bear the closest similarity to those fitted to aircraft. Every Soviet
Soviet Union
The Soviet Union , officially the Union of Soviet Socialist Republics , was a constitutionally socialist state that existed in Eurasia between 1922 and 1991....
- and Russian-derived tank since the T-64
T-64
The T-64 is a Soviet main battle tank, introduced in the early 1960s. It was used solely by the Soviet Army in its front-line divisions and was a more advanced counterpart to the T-62...
main battle tank
Main battle tank
A main battle tank , also known as a battle tank or universal tank, is a tank that fills the heavy direct fire role of many modern armies. They were originally conceived to replace the light, medium, heavy and super-heavy tanks. Development was spurred onwards in the Cold War with the development...
has used an autoloader, allowing a significant decrease of weight and size. Their use has been mostly shunned by American
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
and British
United Kingdom
The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...
tanks, although the American T22 medium tank was one of the first to use an autoloader.
Naval
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
5"/38 Mark 12 can load about 20 rounds per minute.
The Soviet/Russia
Russia
Russia or , officially known as both Russia and the Russian Federation , is a country in northern Eurasia. It is a federal semi-presidential republic, comprising 83 federal subjects...
n AK-130 (twin barrel 130 mm), using autoloading, can achieve up to 40 rounds per barrel per minute.
The Italian
Italy
Italy , officially the Italian Republic languages]] under the European Charter for Regional or Minority Languages. In each of these, Italy's official name is as follows:;;;;;;;;), is a unitary parliamentary republic in South-Central Europe. To the north it borders France, Switzerland, Austria and...
127 mm/5" Compact has similar performance. The largest caliber auto-loading naval rifles were the US 8"/55 Mark 16, deployed on the three cruisers of the Des Moines
Des Moines class cruiser
The Des Moines class cruisers were a group of U.S. Navy heavy cruisers, commissioned in 1948–1949. They were the last of the all-gun heavy cruisers, exceeded in size in the American navy only by the cruisers.-Description:...
class in the late 1940s, and the 8"/55 Mark 71 tested aboard the destroyer USS Hull in the late 1970s. Both weapons achieved a rate of fire of 12 rounds barrel per minute, compared to 3-4 rounds per minute for the preceding hand-loaded weapons.
The advent of jet aircraft, and the rate of fire required to engage them, hastened the adoption of automatic loaders on naval artillery. Development of the loading systems was often problematic, and reliability was seriously compromised in many cases. The US 5"/54 Mark 42 was derated from 40 rounds per minute to 34 to improve reliability. The Soviet/Russian AK-130 was so badly delayed that the missile cruiser Kirov
Soviet battlecruiser Kirov
Kirov, the lead ship of her class of nuclear-powered missile cruisers, is one of the major and biggest surface warships of the Russian Navy, though it was originally built for the Soviet Navy. It is similar in size to a World War II battleship...
(later Admiral Ushakov) was forced to use two older weapons in its place. The US 3"/70 Mark 37 actually spent more time in design (13 years) than in service (12 years) due to severe unreliability. These problems are largely of the past; the state of the art has advanced a great deal, and requirements have generally become less aggressive.
Rate of fire
A modern autoloader for a 120–125 mm caliber weapon in good condition can achieve about 10–12 rounds per minute. This rating may or may not include the time required to bring the gun to the appropriate loading angle (if required) and then bringing it back up to firing angle after loading. This is fast, but not quite as fast as a human loader, for which claims of 15 rounds per minute (at least for a short time) are made.On the other hand, the very newest autoloaders claim to match this rate of fire. Furthermore, it is considered atypical to engage more than a few targets per minute in a tank. The autoloader may also have an advantage over rough terrain that may jar the human loader enough to disrupt his loading cycle.
For weapons above 127 mm, the increased weight of the round pushes this issue decisively in favor of the autoloader. For 6-inch self-propelled artillery, for example, autoloaders can typically achieve 8–12 rounds per minute, while humans typically achieve 4 rounds per minute. For sustained bombardments, this may not be so important for sustained firing rates for artillery is typically only 1–2 rounds per minute, but the rapid-fire capability is vital to shoot-and-scoot
Shoot-and-scoot
The term shoot and scoot refers to an artillery tactic of firing at a target and then immediately moving away from the location where the shots were fired. The reason for this is to avoid counter-battery fire - fired by enemy artillery or delivered by attack aircraft and helicopters, in order to...
tactics to deliver enough fire and then avoid the rapid counterbattery response provided by modern counterbattery systems.
Survivability
The most common autoloaders store their ammunition in the turret basket, increasing the possibility of a catastrophic explosion should the armor around the hull or turret be penetrated. More armor protection, and isolation/separation of the ammunition from the crew compartment has traditionally been available in tanks with a human loader, which can decrease the possibility of cook-off, or protect the crew in case of an ammunition explosion.For example the M1 Abrams was designed to protect the crew from cook-off, and this is accomplished by storing the main gun ammunition in a compartment at the rear of the turret, which is separated from the crew by a rapidly power operated armored door, which is only opened for a couple of seconds each time the loader needs to grab another round, and the top of this compartment has special roof panels that are armored against outside attack, but are much less resistant to pressure from inside, so that if this compartment is penetrated by enemy fire, these panels will vent the explosion generated by the ammunition burning, while protecting the crew. Other western designs from the later cold war era to the present with manual loading have similar protective features. In contrast, the Soviet tanks of the Cold War which employ autoloaders store the ammunition on a carousel in the middle of the crew compartment, where any penetration by enemy fire is likely to incinerate the crew and blow the turret right off the top of the tank.
However, some newer autoloader designs also store the ammunition in an isolated compartment in the turret bustle, with blow off panels on top and the ramming mechanism underneath or in the middle. This allows for much better crew protection, but is disadvantaged because the loading mechanism located in the ammunition compartment reduces the available space and number of rounds that can be carried considerably compared to a similar sized compartment without machinery. With such a design, the loader crew member can be eliminated, but only half the ammunition can be carried ready, in the compartment with the autoloader. Therefore, such a tank usually stores additional ammo in compartmentalized storage at the bottom of the fighting compartment, like older manual loading tank designs. This storage can be surrounded by water, and compartmentalized to some extent, but the reduced crew must still transfer this ammunition to the autoloader at some point. However, such a design can also allow for the rapid replacement of the autoloader and reloading of the ready ammunition by making the compartment at the rear of the turret a modular component that can be easily replaced with appropriate support equipment, similar to how the US MLRS system is reloaded, but possibly even faster. Another possible advantage is that the door that separates the turret can only be large enough for one round of ammunition to slide through, rather than extending across the entire rear of the turret as in the case of the M1 Abrams - this could save additional mass and reduce the power necessary to operate the door, by using less massive armor for the same level of protection, since it would be part of the turret instead of a sliding component in a heavy frame.
Size
Autoloaders are often implemented in an attempt to save on tank size. The T-64T-64
The T-64 is a Soviet main battle tank, introduced in the early 1960s. It was used solely by the Soviet Army in its front-line divisions and was a more advanced counterpart to the T-62...
is an example of this. The current generation of tanks using autoloaders (Russian T-90
T-90
The T-90 is a Russian third-generation main battle tank that is a modernisation of the T-72 . It is currently the most modern tank in service with the Russian Ground Forces and Naval Infantry...
, Japanese Type 90, Chinese Type 98
Type 99
The Type 99, also known as ZTZ-99 and WZ-123, developed from the Type 98G , is a third generation main battle tank fielded by the Chinese People's Liberation Army. It is made to compete with other modern tanks...
, French Leclerc
Leclerc
The AMX-56 Leclerc, commonly known as the Leclerc, is a main battle tank built by Nexter of France. It was named in honour of General Philippe Leclerc de Hauteclocque who led the French element of the drive towards Paris while in command of the Free French 2nd Armoured Division in World War...
) all weigh between 45–55 tons. Tanks that do not use autoloaders tend to weigh in the 55–70 ton range (American M1A2 Abrams
M1 Abrams
The M1 Abrams is a third-generation main battle tank produced in the United States. It is named after General Creighton Abrams, former Army Chief of Staff and Commander of US military forces in Vietnam from 1968 to 1972. The M1 is a well armed, heavily armored, and highly mobile tank designed for...
, German Leopard 2
Leopard 2
The Leopard 2 is a main battle tank developed by Krauss-Maffei in the early 1970s for the West German Army. The tank first entered service in 1979 and succeeded the earlier Leopard 1 as the main battle tank of the German Army. Various versions have served in the armed forces of Germany and twelve...
, British Challenger 2).