Soviet 2B9M Vasilek self-loading mortar

Ernő Lovass & N.R. Jenzen-Jones

The 2B9M Vasilek (‘Cornflower’) is a muzzle or breech-loading, long recoil-operated automatic smoothbore medium mortar. It is a modernised, air-cooled version of the 2B9 water-cooled mortar, itself derived from the earlier F-82 automatic mortar. Development of the 2B9 began in the late 1960s, with the Soviet army adopting the weapon in 1970. The modernised 2B29M was introduced after Hungarian modifications in 1982, and adopted in 1983 (see below). The mortar weighs 632 kilograms and is 4.115 m long in overall length. It is typically mounted on a lightweight wheeled carriage, similar to those seen with field guns, and is equipped with the PAM-1 (ПАМ-1) optical sight. The muzzle can be traversed from -1 ° to +89 °, allowing the weapon to be fired in either a direct- or indirect-fire configuration.

SONY DSC
Figure 1.1 A Russian 2B9M self-loading mortar (source: Dmitry Derevyankin). 

When in indirect-fire mode, with the barrel at a high elevation, the weapon may be operated much as a conventional mortar, with an operator loading single projectiles manually from the muzzle. The 2B9M may also be used for automatic direct fire in the manner of a light anti-tank gun, using the breech-loading feature. Direct-fire sights are provided for this purpose. The maximum effective range for direct fire is approximately 1000 m, with effective ranges for indirect fire between 100 and 4,270 m.

The 2B9M can fire standard 82 mm Eastern Bloc mortar projectiles loaded into four-round en bloc clips which are fed from right to left. Single projectiles (such as illumination or smoke rounds, and/or those using variable charges) may also be loaded individually into the muzzle of the weapon. The weapon has a cyclic rate of approximately 170 rounds per minute, though the practical sustained fire rate was approximately 100 to 120 rds/min in testing. One four round clip can be fired in around two seconds. Depending on the ammunition used, the mortar’s range can be increased up to 4,270 metres. The 2B9M can be seen in use with the Russian military in this video.

2B9M_clip_screenshot
Figure 1.2 Ansar al-Sham militants loading 82 mm mortar projectiles into the four-round clip of the 2B9M mortar (source: Ansar al-Sham). 

A number of tracked MT-LB multi-role armoured vehicles have adapted to carry the 2B9M mortar. The weapon can be towed, but in Eastern Bloc military service it was normally transported under canvas covers on the cargo area of a modified GAZ-66 (4 × 4) 2000 kg truck. The truck would generally carry 226 mortar projectiles, with 96 of those fuzed and loaded into 24 clips. Other mountings have also been developed, including AMB and Unimog mounts. In 2016, Defense Industry of Kazakhstan presented a BMP-1 mounting, known as the BMP-2B9.

The most notable copies of the 2B9M are the Chinese and Hungarian examples. The Chinese W99 is nearly identical in appearance to its Russian counterpart, and shares the same technical characteristics. Hungary received from the Soviet Union in 1973 a licence to manufacture the 2B9; in 1974, two specialists brought the necessary documentation to setup production. The state-owned DIGÉP (Diósgyőri Gépgyár) company, located in Miskolc, modified the weapon to what would become the 2B9M. Soviet engineers checked all modifications and the new design drawings, obliging the factory to make some 600 adjustments in their work, before type classifying the weapon in 1982.

W99
Figure 1.3 A Chinese W99 copy of the 2B9M mortar (source: Norinco). 

After the modifications were deemed successful, Hungary produced all 2B9M mortars for the Soviet Union and Warsaw Pact countries, at a rate of at least 400 guns per year; altogether, this totalled more 2500 updated pieces.

in 1987, the Hungarian factory continued to pursue a further programme of modifications, many arising from the requirements of so-called ‘third market’ countries, many of which had hot, sandy climates. Design changes included different sealing solutions to cope with the ingress of sand and dust, adjustments to the recoil buffer, changes to the lifting lugs and wheel rims to reduce damage during handling, and a general refinement and tightening of tolerances, informed by production experience, as well as other changes which were rejected during the development stage. This modified version was designated the DE-82 in Hungary, and made available for export

2B9M and DE-82 models have been exported to Croatia, Kuwait, Libya, Ukraine, and elsewhere. The weapon has also been used by non-state actors on rare occasions, most often in Syria. Ansar al-Sham, an Islamist militant group operating in Syria, are known to have employed a 2B9M automatic mortar near Mount Chalma, in Syria’s Kesab district, in 2014, for example.


Figure 1.4 A Hungarian copy of the 2B9M self-loading mortar (source: Ernő Lovass).

In the 1990s, the Institute of Military Technology and Mechanikai Művek worked with DIGÉP a private Hungarian company, ARMY COOP kft, to develop the BEKM-82 high explosive anti-tank (HEAT) 82 mm mortar projectile to take advantage of the direct-fire capability of the gun. The body of the mortar projectile was divided into three pieces: an upper and a middle portion (both made of carbon steel), and a precision-machined tail (stabiliser). The round uses a base-detonating impact fuze, rather than a nose-mounted arrangement, and the fuze is fitted with a self-destruct feature. At 1000 m a BEKM-82 impacting at 90 degrees will penetrate 100 mm rolled homogeneous armour equivalent (RHAe). In addition, ARMY COOP also produced an 81 mm version of the 2B9M mortar, as well as 81 mm and 120 mm HEAT rounds. Only 14 examples of the 81 mm mortar were produced.


Figure 1.5 The Hungarian BEKM-82 HEAT projectile (source: patent; Ernő Lovass).

The Hungarians also experimented with mounting the 2B9M to a BMP variant. In 1992, Hungarian designers mounted the 2B9M to the AMB series ambulance variant of the BMP-1, creating what is described as an effective armoured mortar carrier.  The mounting allowed for both direct- and indirect-fire of the gun. With a maximum speed of 65 km/h, this allowed for a rapid redeployment after use in the indirect-fire mode, and with both HE and HEAT rounds made for an effective direct-fire gun targeting personnel, light armour, and structures. The system was limited by early, cumbersome range-finding and fire control computers. More images are provided below.

Figure 1.6 A modified AMB series BMP-1 variant, modified by Hungarian developers to mount a 2B9M mortar (source: Kristóf Nagy).

Cooperating with the Hungarian manufacturer, Picatinny Arsenal in the United States experimented with mounting modified 81 mm 2B9M automatic mortars to the High Mobility Multipurpose Wheeled Vehicle (HMMWW), and tested these extensively. Nicknamed ’Scorpion’ (not to be confused with a later Thales development of the same name, nor with other programs), the effort was quickly assembled by a five-person team led by Anthony Franchino. Whilst most accounts indicated the system was received positively, the weapon has not been adopted by the US military. Nonetheless, the concept lives on in the ongoing testing of the experimental Automated Direct Indirect-fire Mortar (ADIM).


Figure 1.7 An 81 mm Hungarian modification of the 2B9M fitted to an American HMMWV light tactical vehicle (source:  Ernő Lovass).

Technical Specifications

2B9M 82 mm self-loading mortar
Overall length: 4,115 mm
Barrel length: 1,600 mm
Weight: 632 kg
Calibre: 82 mm
Cyclic rate: 170 rounds per minute
Practical rate of fire: 100-120 rounds per minute
Maximum range: 4,270 m
Elevation: -1 to +89 degree

Hungarian AMB mortar carrier
Overall length: 6,760 mm
Width: 2.940 mm
Weight: 13 tonnes
Engine: 16,000 cubic-centimetre V6 diesel producing 22 kW/300 hp
Maximum speed: 65 km/h

Images: Kristóf Nagy

Special thanks to Yuri Lyamin, Kristóf Nagy, and a confidential source.

 

Remember, all arms and munitions are dangerous. Treat all firearms as if they are loaded, and all munitions as if they are live, until you have personally confirmed otherwise. If you do not have specialist knowledge, never assume that arms or munitions are safe to handle until they have been inspected by a subject matter specialist. You should not approach, handle, move, operate, or modify arms and munitions unless explicitly trained to do so. If you encounter any unexploded ordnance (UXO) or explosive remnants of war (ERW), always remember the ‘ARMS’ acronym:

AVOID the area
RECORD all relevant information
MARK the area from a safe distance to warn others
SEEK assistance from the relevant authorities