Thread by @ChungTzuW

(1/) Artillery is often described as the 'God of War', and the late-Cold War Soviet artillery park rivals the Greek pantheon in terms of its diversity. Today, let's take a look at what would arguably be 'Zeus', the 203-mm 2S7 Pion.

(2/) Continuing the charming Soviet tradition of naming self-propelled guns after flowers ('Pion' — 'Peony'), the Pion is easily the most powerful self-propelled artillery (SPA) piece fielded by the Soviets and today's Ukrainian and Russian armies.

(3/) The only Soviet SPA with a larger calibre weapon is the 240-mm 2S4 Tyulpan ('Tulip'), but the Tyulpan is a very specialised weapon whose 240-mm 2B8 mortar was intended for relatively short-ranged destruction of heavy fortifications.

(4/) In the 1950s, the Soviets had developed some truly monstrous SPAs, like the 2A3 Kondensator-2P (Obj. 271) with its 406-mm SM-54 gun, but these were not serially produced as rockets and missiles proved to be more efficient and flexible nuclear delivery platforms.

(5/) In 1967, Nikolai Popov (future chief designer of the T-80) began designing a heavy SPA based on the T-64A chassis. While this design was considered too cramped and was rejected, the need for such a weapon was recognised and development of the Pion was ordered in 1970.

(6/) Leningrad's KB-3 (today Spetsmash) under Popov would develop the Pion's chassis. The question now remained: what gun should it have? Only 3 guns at the time had the required 25 km range: the 180-mm S-23 (left), 180-mm B-1-P (upper), and 210-mm S-72 (lower).

(7/) The Leningrad Artillery Academy eventually concluded that Vasiliy Grabin's 1950s experimental 210-mm S-72 was the most suitable ballistically. But there was a problem: no-one had the tooling to mass-produce 210-mm guns.

war--russia-info.translate.goog/index.php/nome…

(8/) But, the Barrikady Factory in Volgograd did have the equipment to produce 203-mm weapons, since they built the 203-mm B-4. Thus, Barrikady's associated Titan design bureau suggested modifying the 210-mm Z-72 into a 203-mm weapon, and this was approved.

(9/) Their work resulted in the 203-mm 2A44 gun. It is an immensely powerful weapon, capable of hurling 110 kg 3OF43 projectiles at 960 m/s muzzle velocity out to 37.4 km.

(10/) The 2A44 can fire shells using a full (4-Z-2, 43.2 kg, left) or reduced (4-Z-3, 25 kg, right) charge. The primary shell type is the 3OF43 Albatros HE-Frag (left, 110 kg, 17.8 kg A-IX-2 filler).

soviet--ammo-ucoz-ru.translate.goog/index/203_of43…

(11/) There are other conventional types as well:
3O14 Sklad ('Warehouse') cluster munition (24 x 3O16 submunitions, each with 0.23 kg A-IX-2)

soviet--ammo-ucoz-ru.translate.goog/index/203_o14/…

(12/) 3OF44 Burevestnik-2 ('Stormy Petrel') rocket-assisted projectile (102 kg, 13.2 kg A-IX-2 filler, 47.5 km max range)

soviet--ammo-ucoz-ru.translate.goog/index/203_of44…

(13/) In addition to conventional shells, the 2A44 can also fire nuclear projectiles. There are 2 types: Kleshchevina ('Castor Bean', shown) and Sazhenets ('Sapling'). Details on these projectiles are lacking.

(14/) The 2A44 itself can elevate from 0 to 60° and traverse 15° left or right. The barrel and breech mechanisms together weigh 7,975 kg, with the whole gun assembly coming in at 14,550 kg.

(15/) Loading is assisted by a loading/ramming mechanism mounted on the right of the gun, operated by the loader standing on the left of the gun. The mechanism allows the gun to be loaded at any angle.

(16/) A special trolley is used to help handle the massive shells and place them into the lifting mechanism.

(17/) According to Техника и вооружение (TiV) 2019-02, the maximum rate of fire of the Pion is 1.5 shots/minute: 8 shots in 5 minutes, 15 shots in 10 minutes, 24 shots in 20 minutes, 30 shots in 30 minutes, and 40 shots in 1 hour.

(18/) To absorb the 2A44 gun's massive (135 tf) recoil, it has a hydro-pneumatic recoil mechanism. The recoil mechanism is cooled with a special coolant in order to maintain a high rate-of-fire (for its calibre).

(19/) The Pion is also fitted with hydraulic spades to help absorb the recoil. These spades are buried up to a depth of 700 mm before firing, but they cannot be used when the Pion is conducting direct fire. It takes 10 minutes to prepare a Pion to fire from a traveling config.

(20/) In addition to the 2A44 gun, the Pion's crew (according to TiV) is also isuued with an RPG-7, a Strela-2M or Igla MANPADS, as well as other personal weapons.

(21/) The Pion's chassis is based on the T-80's (which was being developed at around the same time). It reuses the road wheels, double-pin live tracks with inner rubber pads, and telescoping hydraulic shock absorbers, and other parts of the suspension.

(22/) However, it is powered instead by a 780 hp V-46-1 V-12 engine instead of a gas turbine. Presumably it did not make sense to use the expensive and unreliable gas turbine on an SPA, where the advantages are pretty minimal.

(23/) Incidentally, Poland received some Pions in the late 1980s, which is why there is a Polish manual for the 2S7. It is currently the only publicly available manual for it that I can find online.

(24/) The transmission is of the 'attached gearbox' (бортовая коробка передач — BKP) type first pioneered on the T-64A and used on every other Soviet/Russian/Ukrainian tank since. My suspicion is that it is derived from the T-72, since it is 7+1-speed, but can't confirm yet.

(25/) As a fairly high-level artillery asset, the 2S7 Pion was not widely exported even to Warsaw Pact countries during the Cold War. Most remain in former USSR countries, of course notably Russia and Ukraine.

(26/) Ukraine had sent most of its 2S7s into reserve prior to 2014, but reactivated them after 2014. They serve exclusively with the 43rd Artillery Brigade, which inflicted grievous ad decisive damage on the Russians during their attempt on Kyiv in 2022.

(27/) Russia also continues to use both the original 2S7 Pion and the modernised 2S7M Malka (aka Pion-M).

(28/28) There really isn't anything quite like the Pion in the West currently. In a conflict dominated by artillery, the Pion is probably the ultimate God of War, highly valued by both Ukrainian and Russian forces.

(29/28)

https://twitter.com/Dawid_92PL/status/1624214004217352193

(30/28) Sklad cluster munitions effect on target

https://twitter.com/Dawid_92PL/status/1634541191252389890

@whatismoo

(31/28) November 2014, a Pion is reactivated.