During the Expomil 2003 international defence exhibition held late in 2003 in Bucharest, Romania, the ATROM 155 mm/52 calibre self-propelled artillery system was shown for the first time.

This has been developed in Romania under the leadership of the local Aerostar SA aviation company, which has extensive experience in the design, development and production of a wide range of 122 mm truck-based multiple rocket launchers (MRLs) for the home and export markets.

The prototype has since been fitted with a new four door fully enclosed cab which is provided with four doors and armoured windows. This was presented during the Expomil 2005 exhibition held in Bucharest.

ATROM essentially consists of the locally developed ROMAN 26.360 DFAEG (6 × 6) truck chassis fitted with the latest version of the Israeli Soltam Systems ATMOS (Autonomous Truck Mounted-Howitzer System) on the rear.

The vehicle is powered by a MAN 2866 LF 24 diesel engine, which develops 360 hp, coupled to a Steyr VG 1600/300 transmission.

The chassis is fitted with a fully armour-protected forward control cab for its crew of five as well as an auxiliary power unit, which enables the 155 mm/52 calibre gun weapon system to be run with the main diesel engine shut down.

ATMOS was originally developed as a private venture by Soltam Systems based on their considerable experience in the design, development and production of 155 mm 39/45/52 towed systems.

When deployed in the firing system the 6 × 6 chassis is stabilised by two hydraulically-operated spades that are lowered at the rear. Standard equipment includes a computerised fire-control system coupled to an inertial navigation system. The installation of a power-operated rammer not only increases rate of fire but also reduces crew fatigue.

The complete ATROM 155 mm/52 calibre system was integrated in Romania and fired for the first time late in October 2003 using various types of ammunition, including 155 mm Extended Range Full Bore - Base Bleed (ERFB-BB) that gives a range of at least 41 km.

As with a number of countries in Eastern Europe, Romania is now moving towards NATO standard calibres for its weapons.

For the Romanian programme the US-based Valentec Systems, a sister company of Soltam Systems, is heading up the programme from the weapon side.

Available details of the ATMOS 155 mm self-propelled artillery, which entered production for an undisclosed export customer in 2003, are given in a separate entry. ATMOS is marketed with 155 mm 39, 45 and 52 calibre barrels.

The computerised fire-control system installed on the ATROM is the same as that used in the Israel Military Industries/Aerostar 160 mm LAROM multiple surface-to-surface rocket system covered in a separate entry. This has been in service with the Romanian Army for several years.