Self-propelled gun

A self-propelled gun (SPG) is a gun, whether it be an artillery piece, anti-tank gun, or anti-aircraft gun, mounted on a motorized wheeled or tracked chassis. As such the gun can be maneuvered under its own power as opposed to a towed gun that relies upon a vehicle or other means to be moved on the battlefield. Self-propelled guns are combat support weapons; they are employed by combat support units fighting in support of, or attached to, the main combat units: infantry and armour.

It may be armoured, in which case it is considered an armoured fighting vehicle (AFV). Although the two are superficially similar self-propelled guns should not be confused with tanks. As a rule self-propelled guns are more lightly armoured and often lack turrets. Tanks are armed with guns designed specifically to destroy other tanks while only some types of self-propelled guns are designed for anti-tank warfare.

Some self-propelled guns are used as artillery pieces in a similar manner to traditional towed howitzers and as such also fall under the umbrella description of self-propelled artillery, but the two terms are not the same and the one is not a sub group or specialization of the other.

The greatest tactical advantage in the case of artillery guns is clearly the greater degree of mobility they have compared to towed artillery. Not only is it important in offering military forces greater flexibility, but it is critical in avoiding attack from the enemy (counter-battery fire) by allowing the guns to change position immediately after firing one or more salvos and before their position can be located ("shoot-and-scoot" tactics). A secondary advantage in the case of armoured – even lightly – guns is the increased protection offered to the gun crews.

Contents

Types

There are four broad types of self-propelled gun; some may be able to fulfill more than one role.

Artillery

A modern Chinese PLZ-45 self-propelled howitzer built for export
A modern PzH 2000 howitzer of the German Army.

Self-propelled artillery and howitzers are used in the same way as their towed variety, generally for long-range bombardment. Self-propelled artillery can however also include other types of weapons not considered a self-propelled gun, one example of which would be rocket artillery.

Assault guns

Assault guns are large-caliber artillery pieces, meant to support infantry by direct fire with high explosive ammunition.

Anti-tank guns

Main article: Tank destroyer

Tank destroyers are self-propelled anti-tank guns with guns powerful enough to be effective against main battle tanks. They are often used in defence and withdrawal operations.

Anti-aircraft guns

These guns are designed to defend against attack by enemy aircraft, but they can also be used for direct fire against targets on the ground in close support of infantry.

Examples

M110 8-in (203 mm) self-propelled howitzer

Sturmpanzer IV Brummbär 15cm StuH 43 L/12 assault howitzer

SU-85 USSR 85 mm self-propelled anti-tank gun

ZSU-23-4 Shilka USSR four-barrelled 23 mm anti-aircraft gun