Heavily Modernised Suspension System for Increased Tactical Agility

At MSPO 2019 in Kielce on 3 September, Huta Stalowa Wola (HSW) revealed the latest iteration of the RAK 120mm self-propelled tracked mortar. The latest model boasts a heavily modernised chassis, using a modern hydro-pneumatic suspension system derived from the LPG (Light Tracked Chassis) programme, which incorporated a modified version of the 2S1 GVOZDIKA self-propelled mortar’s suspension system of Soviet origin, manufactured by HSW until 1993. Developed in 2004, the LPG was developed by HSW in 2009, based largely on its OPAL tracked amphibious armoured personnel carrier (APC).

Currently there are two versions of the RAK – tracked (M120G) and wheeled (M120K). The latter is already in service (64 mortars and 32 command vehicles between 2017 and 2019) within brigades equipped with the ROSOMAK APCs. The first vehicles were delivered in mid-2017. Defence Minister Mariusz Błaszczak recently announced that more wheeled RAK would be ordered soon.

The tracked version, which is destined to be deployed in heavy brigades, equipped with heavy armour, has yet to be ordered, but both types are available for foreign customers. According to a contract signed in 2009 between the Ministry of National Defence and HSW, a so-called ‘company module’ was to include both types. In 2016 Poland ordered eight company modules, each of eight wheeled vehicles.

The idea to introduce new self-propelled mortars originated in 2005, when Poland started to field the Rosomak wheeled APCs. Both have the same mortar, which is based on Patria’s AMOS advanced mortar system. It was revealed by HSW during MSPO 2008.

Both variants are equipped with an automatic loader, which allows the RAK to fire up to 8 shells per minute. The official range is around 12 kilometres. While the wheeled RAK is suitable for rapid deployments, the tracked version can operate in rough terrain without paved roads. Technical parameters of the mortars are almost identical – both are equipped with a fire control system integrated with a ballistic computer, internal and external communication systems, 360° observation sensors, laser-warning system, 81 mm smoke grenade launchers, laser rangefinder and GPS/INS system. Maximum speed is 60 km/h (80 km/h for the wheeled RAK).

Robert Czulda