In 1944 Kolomenskoye SKB began the design of a 240mm super heavy mortar, created to “destroy cities”. The truth is that it was a weapon of an impressive appearance, but entry into service would be delayed for many years due to problems in its design. In 1950 it was approved for service with the Soviet Army, but it was not until 1958 that mass production began.In short, the M-240 was a smooth-bore breech-loading mortar that fired 130 kg grenades almost 10 km away. The tube was mounted on a two-wheel carriage and had a breech and a frame with shock absorbers. In addition, it had a mount with training and balancing mechanisms, the baseplate and a towing bar. The piece had a boom for changing from the firing to the traveling position that also provided stability to the weapon when firing.The tube is mounted on trunions that allow it to be placed horizontally for reloading. The mortar has sights that are only installed at the moment of firing, and are largely protected from the vibration of the shot by the installed shock absorbers. The loading of the mortar was carried out manually and required the work of 5 servers to introduce the grenades of 1.50 meters in length and 130 kg in weight into the breech. The rate of fire is one round per minute.The huge mortar was towed by AT-L, AT-P or AT-S armoured tracked tractors that also carried the crew. The battery was completed with other vehicles that carried the ammunition and various support equipment. The M-240 needed 11 servers and from its arrival at the position until the first shot, lasted about 25 minutes, which gives an idea of the complexity of the preparations. The exit from the position after firing also took a similar time. The mortar has an elevation from +45 to + 65º and a traverse of 18º.There were 5 types of grenades available for the M-240. They were the HE 53-F-864, the HE 3F2 Gagara, the incendiary Sayda, the 3O8 Nerpa cluster type, the laser-guided “Smelchak” and the nuclear 3B11. In addition, 3M15 rocket motors could be installed in this range of ammunition to increase its range to about 18 km. Nuclear grenades were withdrawn in the 90s because the range of the weapon was less due to the great weight of the grenade, which could cause problems for the troops themselves. However, the explanation given to justify their development was that they were safer to use than howitzer shells, since mortar shells supported less pressure and acceleration as they had a much lower muzzle velocity.It can be said that this mortar reached its full effectiveness when variant, designated as 2B8, was installed on an armoured tracked chassis to create the 2S4 Tyulpan self-propelled mortar. The M-240 was exported in small quantities to Egypt (24), Romania and Syria (10) and currently only Syria maintains its 10 units in service. The M-240 service record is quite broad and includes the Yom Kippur War with Syrian Forces, the Afghanistan War with the Soviet Army, the Lebanese Civil War, again with the Syrian Army, and the Syrian Civil War of 2012. In the latter conflict this mortar has been used with devastating efficiency thanks to laser-guided Smelchak (Daredevil) grenades.
