Soviet KV-2 Heavy Tank
On December 19, 1939, the KV-1 Heavy Tank was accepted for the service. At that time, the KV-1 took part in combat tests on the Russian-Finnish War (the Winter War). During those battles, the Soviet High Command come to conclusion that the heavy tank with more powerful armament is highly needed to combat with enemy's bunkers, pillboxes and other fortifications.
The prototype of the KV-2 heavy tank.
The North-Western Front HQ ordered first four KV-1 tanks from experimental party must been armed with 152 mm howitzers. To do this, the best engineers from KTZ's design bureau were summoned. After two weeks a new project was completed. In a first time engineers decided use the 152 mm mod.1909/1930 howitzer, but later it was replaced with more modern 152 mm M-10 Howitzer Model 1938/1940. A new, bigger turret was designed to accept such heavy cannon. That turret was named "MT-1".
At the beginning of 1941, the this tank was renamed to KV-2. Before this, the KV-1 called as "The Tank With a Small Turret", the KV-2 called as "The Tank With a Big Turret". The MT-1 turret was placed on the chassis of a twin-turret experimental tank instead of small turret (a large turret was also removed from the hull). On February 10, 1940, first trials were conducted. At the time, Soviet tank designers weren't very experienced in vehicles of such a heavy weight. They added a small lid on the the howitzer's barrel. That lid was intended to prevent a gun from the dust, shell's fragments and bullets. However, after the first shot this lid was torn away, after that it was never used.
A Giant and a Lilliputian. The KV-2 and the T-26 tanks.
In 1940, a pair of KV-2 were sent to the battlefront on the Karelian isthmus. In spite of some rumors, KV-2s didn't take part in battles before the Great Patriotic War. The pair of KV-2 fired on already captured pillboxes. The results of those tests were excellent and later, in 1940, a KV-2 Heavy Tank was accepted for service. Soviet tankers often called those tanks as "Dreadnoughts".
During the production, the tank's turret was slightly improved and additional DT Machine-Gun was mounted in it. The shortened M-10 Howitzer was able to fire a 52-kg high-explosive projectile with muzzle velocity of 436 m/s. Please notice, only high-explosive shells with reduced propellant charge were used for KV-2's gun. The naval semi-AP round model 1915/28 was alloed to be fired of KV-2, but that round used only in Red Navies and was absent in Red Army's warehouses. Despite some modern "sources", the usage of armor-piercing and anti-concrete ammunition was prohibited - it was recorded in the KV-2's operational manual.
The abandoned KV-2. June 1941.
The KV-2 had 36 rounds for its main gun and 3087 rounds for its bow and rear machine-guns. The crew of six crewmembers: tank commander, gun commander, second gun commander (loader), gunner, driver, and radio operator.
Besides of the 152-mm howtzer, there were some other guns which were either tested or intended to be mount on the KV-2. One of that was an attempt to mount a long barreled 106.7 mm Gun ZIS-6 (initially, this gun was proposed for the perspective KV-3 and KV-5 tanks). From May to June of 1941, the KV-2 with the ZIS-6 was tested on factory's trials, after that it was sent to the ANIOP's trials which it failed. Main problem was with gun's ammunition: the gun had single-loading rounds. Such a lond and heavy shells were wery hard to handle and operate by a single loader.
Trials of the KV-2 armed with the 107 mm ZIS-6 Gun. May 19, 1941.
Additionaly, the KV-2 armed with the 85 mm Gun F-39. Ordered by the NKO, in March 1941, the KV-2 with this gun was tested. Unfortunately, I was unable to find results of those tests.
The KV-2 heavy tank armed with the 85 mm F-39 Gun.
Unfortunately, the new tank had same defects in transmission and chassis as the KV-1. Besides, most of KV-2 tanks didn't have a proper number of ammunition. Nevertheless, the appearance of KV-2 became a shock for German tankers. There wasn't any weapon, with the exception of the 88 mm AA-Gun, that could successfully defeat this beast.
The KV-2 Tank from the 2nd Tank Division delayed the 6th Panzer Division near the Rossienie town. Tank was immobilized by the German's 105 mm Howitzer but continued fighting. It was abandoned when run out of ammo.
Up north, the 6-Panzer-Division under Panzer-Gruppe 4 had encountered Russian heavy tanks. As related in the war diary of Panzer-Regiment 11 on 25 June 1941:
During the morning, the II.Abteilung/Panzer-Regiment 11 together with Kampfgruppe von Seckendorff advanced along the right-hand march route. Throughout the day both units fought off repeated attacks from the Russian 2nd Armored Division. Unfortunately, the Russian 52 ton heavy tanks showed that it was almost insensitive to hits from the 10.5-cm. Several hits from a 15-cm gun were ineffective and bounced off. However, continuous attacks by several Pz Kpfw lV managed to knock out a large number of tanks throughout the day, which allowed our own attack to again drive forward to about three kilometers west of Dubysa.
The bridgehead of Kampfgruppe Raus was held. During the afternoon, as a reserve, a reinforced company and the headquarters of Panzer-Abteilung 65 were pulled back along the left attack route to the crossroads northeast of Rossienie. In the meantime a Russian heavy tank had blocked the communications route to Kampfgruppe Raus, so that contact with Kampfgruppe Raus was broken for the entire afternoon and during the night. An 8.8-cm Flak battery was sent by the commander to fight this tank. It was just as unsuccessful as a 10.5-cm battery whose fire was directed by a forward observer. In addition, an attempt by a Pioneer assault troop using balled explosives failed. It was impossible to get close to the tank because of heavy machine gun fire.
In this photograph a pair of German soldiers can be seen sitting in an abandoned KV-2 heavy tank. The tank was prone to breakdown often which resulted in many tanks being abandoned before they even reached the front lines.
The most of KV-2 tanks were lost because of breakdowns. For example, 41st Tank Division lost 22 KV-2 tanks of 33 tanks total. The only 5 tanks were destroyed by the enemy, other 17 tanks were abandoned because of breakdowns or run out of fuel.
In October 1941, the KV-2's manufacture was cancelled. Totally 334 KV-2 tanks were produced.
Soviet KV-2 Heavy Tank
The KV-85 heavy tank was not an epochal machine in the history of Russian tank design and construction. Although it was not produced in the thousands, this tank still made a contribution to the victory over fascism.
The first attempts to arm a tank with a powerful 85-90 mm gun were undertaken before the war, in 1939. Development of these weapons was going on at the same time. Tests were conducted with production models of the T-28 and KV, but for a number of reasons were not conducted on the armament. Efforts of this nature were temporarily halted with the beginning of the Great Patriotic War.
As early as December 1941, Uralmash Factory recommended the U-12 85mm gun, developed by designers Sidorenko and Usenko, for arming of the KV tank. But the high cost of the gun was excessive for that time and it was recognized as not cost effective to accept it for the armament.
In the spring of 1942 three design groups submitted proposals to the NKV with 85mm tank gun projects: TsAKB (chief-engineer V. Grabin), Kalinin OKB #8, and Factory #92 KB (KB means design bureau) of chief-engineer V. Savin.
All the design bureaus recommended utilization of the mounting and recoil systems of the ZIS-5 or F-34 76mm tank gun, but mounting in them of the 85mm barrel with the ballistics of the type-1939 antiaircraft gun. For compensation of the recoil the TsAKB recommended increase of the recoil mass, OKB #8 -the employment of the muzzle brake of the anti-aircraft cannon, and Savin's design bureau -a redesigned muzzle brake.
All three variants were rejected because at that time, in the opinion of the technical directorate of the NKV and the leadership of the NKTP, transition to an 85mm gun was not justified because the per-round-fired cost of an 85mm gun was significantly greater than that of a 76mm gun.
However, in 1943, after the appearance on the battlefield of the new German Tiger and Panther tanks, and also the inadequate high explosive effects of the 76mm gun against new field fortifications, interest in the 85mm gun re-emerged with new strength.
Projects that had been suggested in 1941-1942 were reexamined, but the most promising of them -the Kalinin Factory #8 design -was rejected because it required use of a muzzle brake, which at that time was considered highly undesirable in a tank gun.
In the winter of 1943, the TsAKB completed the design of a new tank and self-propelled gun cannon, the S-18, which was approved by the NKV technical directorate. Factory #9 was ordered to prepare two trial models in March 1943 (at that time the TsAKB did not have its own production facility). But the preparation of these guns was protracted. When they were finally subjected to testing it was revealed that the guns had been prepared with deviations from the blueprints. Factory #9 KB, under the leadership of F. Petrov, argued that the modifications were appropriate. V. Grabin argued for his original design. Nothing came of the disagreement. The test guns performed normally and rather than correct deficiencies that were uncovered during the tests, the designers and builders undertook liberally to pour dirt on each other. As a result, for testing of the first trial tank -"Object 237" -a non-working model of the S-18 gun was installed in its turret. After the deficiencies of the S-18 were exposed, it was not mounted on the tank but rather given over for prototypes of the SU-85 (SU-85-1 and SU-85-4).
Parallel with the development of the S-18, the TsAKB designed yet another variant of an 85mm tank gun for the KV-1S and IS tanks, which was designated as the S-31. For this reason this gun was being developed right away in two variants -with the ballistics of the 85mm anti-aircraft gun (muzzle velocity of 790-800 m/sec) and with improved ballistics (muzzle velocity of 880-900 m/sec). Factory #92 conducted the preparation and testing of the gun, which showed that in comparison with the S-18 the new cannons were much more technological (simpler and cheaper in production). However, the gun with the improved ballistics demanded development of a new propellant in the existing casing. This complex task was not resolved in the time allotted (by 1 October 1943) and all remaining efforts on the 85mm tank gun were limited to the ballistics of the 85mm Anti-Aircraft Gun Model 1939.
The KV-85 heavy tank.
Meanwhile, the Factory #9 design bureau reworked the design of the U-12 gun and in May 1943 recommended their own variant of the 85mm tank gun. The new model received the designation D-5T and differed from the U-12 in that it had a semi-automatic camming-type mechanism borrowed from the ZIS-5 gun, along with several recoil and return components. The solid construction of the gun and the small length of its recoil permitted it to be mounted in the turret of any existing heavy tank without reworking of the turret. The S-31 had an advantage over the S-18 by having a small recoil length and reduced mass of breech components, but it had a greater number of small parts that required precise machining.
Four tanks (two IS and two KV-1S) armed with the 85mm S-31 and D-5T guns were tested jointly. This test demonstrated the great operational superiority of the D-5T gun and it was accepted for armament.
For these tests the S-31 gun was mounted in the standard KV-1S turret with minimal reworking. The crew had been reduced to four men. This tank (Object 231, serial number 30751-51) is now preserved at the VIM BTVT at Kubinka.
Despite the success with the KV, work on a new future IS-85 tank was dragged out at the same time that the front was demanding new tanks with powerful armaments. It was necessary to withstand for several months before the introduction of the IS-85. A way out was found. The design bureau of J.Y.Kotin decided to come up with a modernisation of the KV-1S tank, mounting on it the turret of the IS-85 tank with the D-5T gun.
The KV-85 heavy tank on pedestal at Avtovo. This is the sole production vehicle of this type preserved to this time. During restoration of this vehicle the hull machinegun was mounted incorrectly.
The following work was accomplished during the mounting of the new turret on the KV-1S: the under-turret box, in which the enlarged-diameter ring of the improved tank turret fit with difficulty, was widened. The basic load of 70 main gun rounds was stored in improved racks. With the placing of the gun and the ammunition racks, the designers had to delete the fifth crewmember -the gunner-radio operator, for whom there was no longer any space. The hull-mounted DT machine-gun, which previously was carried in a movable ball mounting, was now fixed. The power pack, transmission, and suspension components were taken straight from the KV-1S.
The first KV-85s were re-worked from excess KV-1S hulls, welding up the hole for the ball-mounted hull machine gun. The incorrect opinion has appeared in Western literature that there was a "second version" of the KV-85 with a flexible front machine gun. This confusion most likely arose as a result of study by Western experts of the only KV-85 tank that has been preserved to this day (monument in Avtovo, St.Peterburg), where a mistake was made in the restoration process. According to archival data, 148 KV-85 tanks were produced; they were sent to the front beginning in September 1943. Simultaneously, output of the KV-1S tank was continued until December 1943.
Factory #9 was given an order for production of the D-5T, but it turned out to be rather difficult for the factory. The factory was completely incapable of simultaneous production of guns for the IS-85 and KV-85 and for the T-34-85. Factories #8 and #13 were dedicated to mass production of the D-5T. These problems with production of the gun prevented the KV-85 from becoming a mass tank. By the spring of 1944 the IS-2 entered mass production with incomparably greater armament and armor, and the subsequent fate of the KV-85 (and also the IS-85) was sealed.
KV-85 in Action
A great portion of the KV-85s in the guards tank breakthrough regiments ended up on the Southern Front (2nd formation), later the 4th Ukrainian Front, where they participated in the liberation of Ukraine and the Crimea. Because on the whole our tank was not superior to the German heavy tanks, battles were fought with varied success. The results depended primarily on the training of the crews of the opposing sides and on the tactics they selected for the engagement.
The 34th Guards Heavy Tank Breakthrough Regiment (TTPP) (total 20 KV-85 tanks), which together with the 40th Heavy Self-Propelled Artillery Regiment (TSAP) (total 9 >SU-152s), fought in the area of the village Ekaterinovka on 20-25 November 1943 as element of the 28th Army of the 4th Ukrainian Front.
On 20 November both regiments in a two-echelon formation attacked enemy positions that in addition to artillery had Pz.Kpfw IV Ausf.H and Marder II self-propelled guns (up to 18) dug into their positions. In the course of the day the tankers and self-propelled artillerymen managed to capture the first lines of the German trenches, losing 6 KV-85 tanks (left in enemy-controlled zone) and 6 SU-152 guns in the process. On the second day of the battle up to 10 Pz.Kpfw IV Ausf. H undertook a counterattack on the positions of Soviet troops. The attack was beaten off by the efforts of the infantry and both tank regiments, costing the enemy five tanks without any losses on Soviet side. On 23 November all serviceable vehicles in the regiment again attacked the German positions, broke through their defenses, and advanced 5 kilometers in deep. An additional two KV-85 tanks were lost in this operation (one of them burned up). The 34th Guards TTPP was sent to the rear for repair on 23 November and only the 40th TSAP continued to fight until 28 November, losing one or two vehicles daily in combat.
Along with the 19th Tank Corps, the 1452d Separate Self-Propelled Artillery Regiment (SAP), which was equipped with 11 KV-85s, 5 KV-1S's, 6 SU-152s, and also 3 SU-76s, participated in the liberation of the Crimea. It seems that because of a severe shortage of self-propelled guns, someone decided to equip the SAP with KV tanks, which had the most destructive armament of all the tanks presented in the Crimea at that time. The 19th Tank Corps had only the T-34-76s and light tanks, and the enemy had two brigades of assault guns: the 191st and 279th under the command of Major Mueller and Captain Hoppe (altogether the XVII German Army had 215 tanks and self-propelled guns, primarily the StuG III with 75mm cannons). But for a number of reasons associated with the leadership of the operations, the regiment fought with the masterfully retreating German infantry, who broadly employed mines.
The KV-85 heavy tank.
On 8 April 1944, in accordance with the order of the commander of the 3rd Guards Rifle Division, to which the regiment (11 KV-85, 5 KV-1S, 2 SU-152) was operationally subordinated, the tankers and infantry, who had concentrated 1.6 km south of Turetskiy wall, attacked the enemy positions from the west to capture the town Armyansk. Several minutes after the launching of the attack the regiment blundered into a minefield that was unknown for the Russians and therefore not marked on the map. Sappers designated for mine clearing were on the tanks and could not dismount because the Germans opened up on them with all types of weapons. Paradoxically, three hours after the launching of the attack, the 1452nd SAP still managed to break through the enemy defenses, losing 1 burned-out KV-85, 3 KV-85s blown up by mines, and 5 KV-1S's, 4 KV-85s, and 2 SU-152s damaged by enemy gunfire. No personnel were killed, but 2 officers and 4 soldiers were wounded. The 3 remaining operational KV-85s and 5 KV-1S's with an assault force from 3rd Guards Rifle Division reached the town Armyansk at 14:00 on 8 April. The regiment had accomplished its assigned mission. As a result of this battle, 11 pillboxes, 5 antitank guns, and up to 200 enemy soldiers and officers were destroyed. Thus, the basic losses in personnel and equipment were caused by insufficiently competent leadership, which was unable to organize coordination of various branches of troops during the breakthrough of the German defense.
The regiment repaired its equipment until 10 April 1944 and on 11 April a tank group (3 KV-85s 2 SU-152s, 2 SU-76s) of 1452nd SAP again attacked the German defenses in the area of Ishun. Tanks supported the infantry of the 3rd Guards Rifle Division. Because reconnaissance was not conducted, the tanks rolled into an 8-meter antitank ditch and special tank traps that were similar to ditches. The attack failed. A pair of KV-85s and SU-76s was recovered from the ditches with the aid of tractors. After this grievous experience of the use of heavy tanks, the command of 2nd Guards Army decided to make a radical change in the tactics of the employment of this unit. The more so because on 10-11 April the Germans began to organize the withdrawal of their forces toward Sevastopol. On order of the commander of 2nd Guards Army (#005/OP of 10 April 1944), the vehicles of 1452nd SAP and 512th Independent Flamethrower Tank Battalion (OOTB) were parceled out to army mobile detachments. These detachments consisted of infantry on Studebaker trucks and also tanks and self-propelled guns, and had the mission as rapidly as possible to break through to Sevastopol. KV-85 tanks also were assigned to these detachments.
Operational group of 1452nd Heavy Self-Propelled Artillery Regiment, attached to the 512th Independent Tank Battalion, on the street of liberated Evpatoria. April 1944.
Engagements with the StuG III were exceedingly few -the Germans were retreating under the cover of artillery and mine fields. A group under the command of Hero of the Soviet Union Guards Colonel Puzanov (1 T-34, 8 TO-34s, 4 KV-85s) liberated the towns Evpatoria, Saki, and Bakhchisaray. On 6 May 1944, once again formed into a unit, 1452nd SAP, now comprising only 1 KV-85 and 2 SU-152s, reached Sevastopol and fought in the area of Mekenziev Hills, supporting the 37th Guards Rifle Division. On 9 May the two serviceable vehicles of the regiment, a KV-85 and an SU-152, broke into Sevastopol with the 264th Guards Rifle Regiment.
The KV-85 rarely engaged enemy tanks and SP-guns during the liberation of the Crimea, and was employed primarily as a self-propelled gun for support of infantry.
The employment of the KV-85 against the German heavy tanks Pz. Kpfw VI Ausf. H occurred in the zone of combat actions of 38th Army, 4th Ukrainian Front, on 28 January 1944. During this battle Soviet tankers acted decisively and skillfully, not harboring any unfounded illusions regarding the training of the German tankers and the quality of their combat vehicles. An operations summary concerning the combat actions of armored and mechanised forces of 38th Army from 24 to 31 January 1944 to the 7th Independent Guards Heavy Tank Regiment (7th OGTTP) speaks to this. This regiment was covering the withdrawal of units of the 17th Rifle Corps, which had fallen into semi-encirclement as a result of a German counteroffensive.
In accordance with a combat order of headquarters, 17th Corps, the remaining 5 tanks and SP-guns (3 KV-85s and 2 SU-152s) by 07:00 28.01.44 occupied all around defense at Telman sovkhoz (collective farm) and were prepared to fend off enemy tank attacks toward Rososh, Kommunar sovkhoz, and Bolshevik sovkhoz. Some 50 infantrymen and 2 antitank guns were set up in the defense around the tanks. An accumulation of enemy tanks had been spotted south of Rososh. At 11:30 the enemy launched an attack from the south on Telman sovkhoz in the direction of Rososh with up to 15 T-6 tanks and 13 medium and light tanks.
The KV-85 heavy tank damaged in the Melitopol area, November 1943.
Occupying favorable positions, because of the cover provided by their fortifications and haystacks, and having permitted the enemy tanks to approach to battlesight range, our tanks and SP-guns opened fire and broke up the enemy combat formations, destroying 6 tanks (of these, 3 Tigers) and up to a platoon of infantry. The KV-85 of Senior Lieutenant Kuleshov was designated to liquidate the German infantry that penetrated our position. He fulfilled this assignment with fire and his tracks. By 13:00 of the same day the German troops had decided not to attack the Soviet position frontally, bypassed Telman sovkhoz, and surrounded the Soviet grouping.
The battle of our tanks in encirclement by superior enemy forces was characterized by the extreme skill and heroism of our tankers. A tank group (3 KV-85s and 2 SU-122s) under the command of company commander Guards Sr. Lieutenant Podust, defending Telman sovkhoz, simultaneously prevented the German forces from being shifted to other areas of battle. His tanks frequently changed firing positions and conducted well aimed fire at German tanks. The SU-122s, exposing themselves, fired at infantrymen riding in transporters and moving along the road to Ilintsa, which limited the freedom of maneuver of German tanks and infantry and, in the main, made possible the escape from encirclement of units of the 17th Rifle Corps. The tanks continued to fight in encirclement until 1930, although there were no longer any infantrymen in the sovkhoz. Maneuver and intensive fire, and as well the use of cover for conducting fire permitted them to suffer almost no losses (only 2 wounded), while inflicting significant personnel and equipment losses on the enemy. Through 28.01.44 the Germans lost (both damaged and destroyed) 5 Tiger tanks, 5 T-4 tanks, 2 T-3 tanks, 7 armored transporters, 6 antitank guns, 4 machine-gun positions, 28 wagons with horses, and up to 3 platoons of infantry.
At 20:00 the tank group broke out of encirclement and by 22:00, after a firefight, reached the position of Soviet troops, having lost 1 SU-122 (burned up)".
Countless examples of the employment of the KV-85 tank demonstrated that the 85mm gun was an effective weapon against German heavy tanks (Panther and Tiger) and should have been mounted on the T-34 medium tank, which in fact it was, later. Even before the operation for the liberation of the Crimea, commanders of mobile pursuit detachments complained of the fact that the KV-85 and SU-152 were not fast enough and fell behind their infantry-carrying trucks. It was understandable, given that the KV-85 was a heavy tank. However its low maneuverability and speed was compensated for by its powerful armor and armament. And if the survivability of the KV was considered at that time to be sufficient, then the gun required significantly more power so that it could defeat German equipment at maximum ranges.
Standard KV-85 tank with the D-5 gun in enlarged IS tank turret.
In accordance with the results of the combat actions of the KV-85, the designers and military decision makers concluded that subsequent modernisation of the KV tank family was not appropriate. While the 85mm gun was adequate to defeat German tanks, it lagged behind German tanks in its armor-penetrating capability when fired at long ranges. Soviet heavy tanks were weaker in armor than their German counterparts. Consequently, the concept of medium and heavy tanks (T-34 and KV) armed with a cannon of a single caliber was outdated. It was necessary to have a heavy tank with a powerful gun that was superior to the German 88mm gun in all basic parameters.
These conclusions were considered during the creation of the IS-2 tank with its 122mm gun and during the expansion of the production of the 85mm cannon for the >T-34-85.
As concerns the KV-85, in view of their small quantity in production and intensive employment, only isolated tanks of this modification remained in the forces by the middle of 1944.
At the present time two KV tanks with the 85mm gun have been preserved. One of them is the KV-85 mounted as a memorial in the area of Avtovo in St.Peterburg. The other is a production KV-1S armed with the 85mm Tank Cannon S-31 in standard turret located in the Museum of Armored Vehicles at Kubinka, near Moscow.
Experimental Vehicles
The KV-122 experimental heavy tank.
Attempting to increase still greater the firepower of the KV tanks, and also for development of new artillery systems on a "live" tank chassis, it was suggested to mount the 100mm Gun S-34 in the turret of a KV-85. The new vehicle was designated the KV-100. After testing, the turret of an IS-2 tank with the 122mm Gun D-25 was mounted on the KV-85 chassis. Although no principal problems resulted from this reworking, the design was rejected because the IS-2 had already been placed in mass production.
In 1943, carrying out a personal order of I.V.Stalin, the artillery design bureau attempted to give a second life to the KV-2 heavy assault tank, as very necessary for the destruction of enemy defenses. The primary problem in this regard was the fact that it was necessary to mount the 152mm howitzer in a standard turret of the KV-1S. The TsAKB and OKB #9 were engaged in secret competition for the development of this artillery system. Both collectives drew the conclusion regarding the principal necessity of using a high-efficiency muzzle brake in the construction of their gun. OKB #9 already had a recommendation for adopting the 152mm Field Howitzer D-1 as standard. Therefore, during the creation of a tank variant, its recoil components were carried over to the carriage of the D-5T tank gun. Thus far no significant proof has been found that the D-1-5 (or D-15) howitzer was mounted even on a single KV, but an SP-gun on the T-34 chassis with armament from the "152mm Tank Cannon D-1-5" had been considered for some time as a future variant to replace the SU-122.
The KV-152 experimental heavy tank.
The TsAKB took a slightly different path. Here they preserved the designs of the ZIS-5 and S-31 guns, but somewhat strengthened them. Production proceeded without problems and a KV with an S-41 152mm howitzer was demonstrated to Marshal Voroshilov during his visit to the TsAKB in August 1943. Unfortunately, no additional details are known about this vehicle.
In view of their futility, all experiments with 152mm howitzers in tank turrets were halted by order of the NKV in October 1943. The SU-152 already was slated for fielding and work was being conducted on the creation of the IS-122 (IS-2).
Additional Sources: www.user.dccnet.com
gunpoint-3d.com
www.russianwarrior.com
ww2photo.mimerswell.com
rkkaww2.armchairgeneral.com
www.tracks-n-troops.com
www.granddadshobbyshop.com
www.geocities.com/pentagon/quarters/4635/tanks
rkkaww2.armchairgeneral.com
www.militarymodeler.com
www.nemo.nu/ibisportal/5pansar/5sidor
My understanding is that German tankers found the D-25 122 mm (about five inch bore) gun on the IS-2 intimidating.
The 85 mm D5-T was in production into the 1960s, I think, for an airborne assault - antitank vehicle.
Above from a cool site, Looks like he got ahold of a translation of a technical manual.
