Auto Loaders in Tanks

An auto-loader(generally used in tanks and artillery) replaces the human loader who would load ammo into the main armament of the tank/artillery without being an integrated part of the gun itself. An auto-loader extracts a shell and a propellant from the ammo rack and loads into a magazine or belt(if the gun has it) or directly into the gun if it doesn't.

History

Development on auto-loaders started in the beginning of WW2. Their first combat use was in tank-buster aircraft such as the 75mm Bordkanone BK 7,5 cannon-equipped HS 129 B-3. Every Soviet/Russian tank after the T-64 has also used an auto-loader.

Their use has been mostly shunned by American and British tanks, despite the American T22E1 medium tank being one of the first tank designs to use an autoloader. After the middle 20th century, autoloading became common on large (76.2 mm caliber or greater) naval guns. 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.

Advantages

Auto-loaders reduce the size of the vehicle as they are replacing a crew member. This makes the vehicle smaller, easier to conceal, harder to hit and faster. A smaller vehicle reduces the amount of area that needs to be armored and an auto-loader can not get fatigued like a human loader.

A modern auto-loader for a 120–125mm gun can achieve a rate of fire of about 10-12 rounds per minute if it has been maintained properly

Disadvantages

Most auto-loaders store their ammo in the turret basket. This increases the chances of an ammo cook-off if the armor around the hull or turret be penetrated. Blast doors, and separation of the ammo storage from the crew compartment has been available in tanks with a human loader, which can protect the crew if the ammo is hit.

Some Western designs, such as the Leclerc tank, store the ammo in a separated compartment in the bustle with blowout panels and the ramming mechanism in the middle, or below. This has much better crew safety but the ammo in the bustle is reduced due to the auto-loader taking up space. Such a tank usually stores additional ammo in compartmentalized storage at the bottom of the fighting compartment. This can be surrounded by water, but the reduced crew must still transfer this ammo to the auto-loader at some point.

Such a design can also allow for the rapid replacement of the auto-loader 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.

Source - wikipedia
info gathered by - Strv 74#3676 from defence matrix discord