2S7 "Pion"

   The 2S7 "Pion" Self-Propelled Gun features turretless design with rear opened placed main gun. Driving compartment is in the front section and engine-transmission compartment is right behind it and crew compartment and combat compartments go further. Artillery unit's crew is 14 men. On march 7 of them are carried by self-propelled artillery gun while others in convoying truck or armored personnel carrier.

   Commander and driver have their seats in the driving compartment. Cabin is protrudes forward creating counterweight for the main gun. Cabin features two roof hatches. Forward observation is provided threw the windscreens or periscope observation devices. However windscreens can be covered with an armored shutter. There is also a forward-facing periscope in the forward part of the roof between commander and driver. In the combat position gunner seats at the rear of the hull on the left side. Gunner operates elevation and traverse controls.

   At the rear part of the hull there is very powerful 2A44 the 203-mm artillery gun. Gun has no muzzle brake. This design decision was caused of a low pressure dangerous for crew while mounting muzzle brake some additional protection measures had to be taken. Gun's lock is automatically opened and closed by a special mechanical device. However this operation can be done manually in emergency situation. Projectile and load are loaded by load-assisting mechanism. This loading mechanism works in any gun's elevation and traverse inclination levels. Loading operations are made from locker's deck.

   Over and under the gun there are mounted hydro-pneumatic recoil absorbers. Recoil step is approximately 1 400 mm. The 2S7 "Pion" is completed with rear mounted bulldozer type hydraulic operated spade. It digs in the ground approximately 700 mm and provides good fire stability. Fire stability is also ensured by landing directing sprockets and blocked wheels hydro absorbers. All these features allow to fire in a wide range of elevation and traverse ranges. Elevation range is between 0° and 60° and traverse range is 30° (15° to the each side). In a low elevation levels or using low power loads fire is executed without lowering spade and other recoil absorbing measures.

   Ammunition is separately loading type. The main is OF43 High-Explosive Fragmentation Projectile and rocket assisted projectile. High-explosive fragmentation projectile weights 110 kilograms and consists 17.8 kilograms of explosives. Such projectiles maximum range of fire with a normal load is 37.5 kilometers and initial speed - 960 m/s. Rocket assisted projectile weights 103 kilograms and contains 13.8 kilograms of explosives. It's range of fire is a record for a modern field artillery and is 47.5 kilometers.

   Without already mentioned ammunition the 2S7 "Pion" Self-Propelled Artillery Gun fires concrete piercing, chemical and also tactical-nuclear projectiles. Combat load consists from 40 rounds however only 4 of them are carried by self-propelled artillery gun for immediate use and remaining - by convoying vehicle. In fire position ammunition is lowered to the ground and carried to artillery unit using one-axis barrow.

   Maximum rate of fire is 1.5 rounds per minute. However there are intended later firing modes:

   - 8 rounds in 5 minutes;
   - 15 rounds in 10 minutes;
   - 24 rounds in 20 minutes;
   - 30 rounds in 30 minutes;
   - 40 rounds in one hour.

   Especially for the 2S7 Artillery Gun in Leningrad (now St. Petersburg) Kirovsk Plant there was developed and produced special tracked chassis (object 216). Exactly this plant made final assembling of the 2S7. It's artillery part was supplied by "Barikady" Plant. Vehicle is powered by V-46-1, the V-type 12-cylinder diesel engine completed with turbocharger. It reaches maximum power of 750 hp. Furthermore "Pion" is fitted with auxiliary 24 hp. diesel engine for autonomic electricity supply. Mechanic transmission with a conical reducer and board gear boxes are similar to the T-72 Main Battle Tank.

   Chassis features 7 doubled rubber wheels and 6 supporting rollers mounted from the each side. Wheels suspension is individual, torsion with stopping hydro absorbers. Driving sprocket is placed front and the rear sprocket is lowered to the ground in combat order. A great number of chassis elements are similar to the T-80 Main Battle Tank.

   The 2S7 "Pion" features quiet high mobility for a such mass vehicle. Considering that preparing for the march position time is set to minimum, artillery unit in principle is able to fire 1-2 rounds and leave it's position while the first round will defeat target in 47 kilometers range.

   Vehicle is equipped with a tank internal communication device, radio equipment and fire prevention equipment. In addition it is completed with nuclear, biological, chemical protection system and night vision equipment.

   During the 2S7 Self-Propelled Artillery Guns improvement works in 1983 it was additionally fitted with data receiving and monitoring devices. During the improvements rate of fire was increased to 2.5 rounds per minute and carried ammunition load was increased to 8 projectiles with loads. Improved self-propelled artillery gun is designated as 2S7M "Malka".

Advantages

   The 2S7 has the longest range of fire comparing with any other modern field artillery unit. It is able to fire and leave position before projectile hits target. Powerful projectiles. Some mechanisms are interchangeable with a widely used T-72 and T-80 Main Battle Tanks.

Disadvantages

   Low chassis service life. Out-dated fire control equipment (only with not improved models). Only some projectiles can be carried by artillery unit itself for immediate fire.