The Lyagushka or D-30 series has a unique three-trail carriage, a conspicuous box-like shield for the recoil-recuperator mechanism mounted above the tube, and a
small protective shield which is fitted between the wheels. It is towed muzzle-first by a large lunette just under the muzzle brake, with its trails folded
under the barrel. It can be towed it at speeds up to 80kph.
In firing position, the crew of eight unhitches the gun; it lowers the central emplacement jack, raising the wheels high enough to clear the trail legs; and it
spreads the two outer trails 120° on each side. The revolving mount permits 360° traverse and is equipped for high and low angles of fire. This
makes the D-30 fully suitable for antitank defense. The D-30 can also be equipped with a IR or passive night vision sights for direct fire.
The gun has a semiautomatic, vertically sliding, wedge-type breechblock.
The D-30 fires the following variable-charge, case-type, separate-loading ammunition: FRAG-HE, HEAT-FS. Other types of projectiles include chemical,
illuminating (S-462 weighing 22.4 kg), smoke (D-462 weighing 22.3 kg), leaflet, flechette, incendiary and recently an RAP has been introduced with a
maximum range of 21900 m. There are at least two chemical projectiles for the D-30. The Sarin projectile weighs 22.2 kg of which 1.3 kg comprises the
Sarin CW. The 122 mm viscous Lewisite projectile weighs 23.1 kg of which 3.3 kg comprises the viscous Lewisite CW agent. In both cases the CW agent
is dispersed by the explosion of a TNT bursting charge.
