Difference between revisions of "Autoloader"
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Latest revision as of 14:24, 15 March 2013
An auto-loader or autoloader is a mechanical aid or replacement for the personnel that load ordnance into crew-served weapons, such as tanks and artillery. The term is generally only applied to larger weapons that would otherwise have a dedicated person or persons loading them; the mechanism that automatically loads automatic weapons is not considered an auto-loader.
An auto-loader, 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. Theoretically, by automating the loading process, it should streamline and speed up the loading process, resulting in a more effective fighting machine. Also, since an auto-loader 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 in the real world.
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[edit] History
Auto-loaders were developed at the beginning of World War II. Their first combat use was in tank-buster aircraft such as the 75mm-equipped Henschel Hs 129. 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.
[edit] Issues with autoloaders on ground vehicles
In the modern era, autoloading is ubiquitous on any large (3–5 inch, or 76.2mm–127mm) 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.[1] The Soviet/Russian AK-130 (twin barrel 130 mm), using autoloading, can achieve up to 40 rounds per gun per minute.[2] The Italian 127 mm/5" Compact has similar performance. Another example is the USS Des Moines 8-inch guns, which can fire 10 rounds per minute when other guns of the same caliber can only do 2 rounds per minute.
The advantage in speed, resulting in greater firepower, makes autoloaders the logical choice for ships. The contest, however, is a lot closer for ground vehicles.
[edit] Reliability
Experiences with the reliability of autoloaders in tanks have been mixed. Some Soviet models, such as the T-64, have had very reliable autoloaders, while others, such as the T-72, have had less reliable autoloaders. The American M8-AGS (cancelled) autoloader was supposed to work quite well, while the Stryker Mobile Gun System's autoloader is supposed to be poor. In any case, it is quite unlikely that an autoloader can be as reliable as a human loader. If the autoloader fails, manual loading becomes very awkward because the autoloader takes up most of the required space.
[edit] 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.[3] 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 125 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.
[edit] Survivability
Another common, but not universal, issue is survivability; many autoloaders store their ammunition in the turret basket, increasing the possibility of a catastrophic explosion should the armor around the ammunition be penetrated, although such a penetration is unlikely in this location. However, an autoloader also allows for the crew to be located within the hull of a tank instead of in the turret, increasing the probability of survival.
[edit] Size
Autoloaders are often implemented in an attempt to save on tank size. The T-64 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, British Challenger II).
[edit] The relative value of the fourth crew member
Autoloaders are often criticized for replacing the fourth member of the crew. The loader represents a lookout, emergency backup driver/gunner, mechanic and sentry, all of which are lost when replaced with an autoloader.
On the other hand, this saves on training costs per tank. It can also be argued that while the loader has marginal utility in all these auxiliary roles, his primary role can be replaced with a machine quite well, so he can be reassigned for greater overall utility. For example, in a tank platoon of three tanks, a switch to autoloading means three outstanding crew members. They can man a fourth tank, which will arguably go a long way towards compensating for any autoloader weaknesses. They can also be retrained as dedicated mechanics, or as a SAM team to provide anti-air protection.
