The AHS Krab (Crab) is a 155 mm NATO-compatible self-propelled tracked howitzer designed in Poland by Centrum Produkcji Wojskowej Huta Stalowa Wola combining K9 Thunder chassis, a AS-90M Braveheart turret with 52-calibre gun and WB Electronics “Topaz” artillery fire control system. The 2011 version used a Nexter Systems barrel and UPG chassis. The 2016 production batch utilize the K9 chassis and a Rheinmetall barrel. The KRAB can be ready to fire in less than 1 minute and leaves its firing position in 30 seconds. In December 2016, The Polish Company Huta Stalowa Wola (HSW) has signed a contract for the delivery of artillery vehicles to the Polish Army for a total amount of €1 billion including 24 Krab 155mm self-propelled howitzer armoured vehicles. As of 2016 full-rate production of 120 Krabs for Polish Army has started with 16 guns completed and deliveries to be completed by 2024.
The KRAB turret is mounted at the rear of the tracked chassis. Turret traverse is through a full continuous 360º and weapon elevation is from -3.5° to +70º. Elevation and traverse drives are both electric and operate at a rate of 10º/s. Main armament of the KRAB consists of one 155mm 52 calibre designed and manufactured by BAE Systems. The gun can fire all standard 155mm NATO projectiles with a range from 4.7 to 40 km. An automated loading system enables the gun to fire with a burst rate of three rounds in fewer than ten seconds, an intense rate of six rounds a minute for three minutes and a sustained rate of two rounds a minute.
Standard equipment of the KRAB 155mm self-propelled howitzer includes night vision for the driver, direct fire sight, NBC protection system, automatic fire suppression system and a laser range-finder. The vehicle also integrates a navigation system and a DD-9620 terminal providing target information. The muzzle velocity measuring system above the main gun feeds information to the fire-control system. The ZZKO TOPAZ fire-control system controls the turret, gun layer computer and other subsystems. The KRAB is also fitted with an auxiliary power unit for the turret to ensure the use of on board electrical and electronic equipment during shut down of the main diesel engine.
The KRAB vehicle can carried a total of 40 shells and 48 charges, with 29 rounds in the turret and 11 in the chassis. For its self-protection, the left hatch on the roof turret is fitted with a 12.7 mm machine gun which can be used against air and land targets. Four 81mm smoke grenade dischargers are mounted on each side at the front of the turret. The Krab weighs 48 tons, it is enabled with a maximum speed of 60 kph (37 mph), and it can carry a crew of five. The KRAB is able to negotiate a gradient up to 25° and side slopes to 20°. The vehicle can traverse a vertical obstacle of 0.8 m and a trench of 2.5 m. It can ford a depth of 1 m without preparation.