The AS90 is a modern self-propelled gun that is in service today with the British army and the Polish army. Entering service in 1993 with the British army the AS90 replaces the ageing Abbot and American made (and still in service with the Americans) M109.
The AS90 has a crew of 5 that includes a driver, a commander, a gun loader, a gun layer (targeting) and an operator to co-ordinate the battery. The British army has at the moment 179 AS90s.
The AS90 is equipped with an autonomous navigation and gun laying system (AGLS) which means that the AS90 can fire independently without line of sight. The targeting movement of the gun is entirely computer controlled, allowing turret rotation and elevation to within 1 mil (1 mil = 0.05625 degrees). For line of sight targets the AS90 has a day/night sight for the gunner.
The AS90’s primary weapon is the 155mm gun of either 39 or 52 calibre. This gun has 3 main firing modes: Burst, Intense and Sustained. Burst fire enables a 3 round burst to be fired in under 10 seconds, Intense is 6 rounds per minute and Sustained is 2 rounds per minute. A single AS90 operating in Burst fire can put a 130.5kg payload onto a target in 10 seconds. One battery (eight) of AS90s can put 1044kg of explosives down in 10 seconds. The AS90 can fire many types of shell; though high explosive is the most common it can also fire smoke, illumination, cluster bomb or the longer ranged (at the expense of payload) rocket assisted shell. The range for the basic non-assisted shell is 24.7km and 30km for assisted shells. The 52-calibre gun has a range of over 40km. 48 155mm shells can be carried inside the AS90. On top of the turret is a mounted 7.62mm GPMG for Anti infantry or Anti air purposes, although batteries are usually defended by one or more Rapier anti-air systems.
The AS90’s armour is made from welded steel and can withstand a direct hit from 7.62mm and 14.5mm rounds. Although it cannot withstand a direct hit from a 152mm shell it can stop fragments coming from one.
A 660hp V8 engine is installed which enables a maximum speed of 53km/h and maximum gradient of 60%. The AS90 has a range of 420km over flat terrain.