Overview[]
The IS-2M is an improved version of the IS-2 Soviet heavy tank developed in the late 1950s.
Development[]
During the operation of IS-2 during peacetime after the war, reliability issues of the engine, gearbox, clutch, onboard gearboxes, and chassis components were revealed. The technical documentation began in SKB ChKZ in 1954 and by GBTU's decision in 1957, using the experience gained from the development of IS-3, improvements were made to the IS-2 during its overhaul by installing more modern equipment. The design changes developed by specialists in the factories of the Ministry of Defense, 7th BTRZ (g. Kiyev), 7th BTRZ (L'vov), and 120th BTRZ (Kirkhmyezyer, GSVG) were introduced in 1957 - 1959. In 1960, the vehicles received the IS-2M name. The modernization of the tanks was carried out until the end of the 1970s, while the vehicles were decommissioned in 2008.
Design[]
The main changes of the modernization were, an increase in ammunition capacity of the main gun, removal of the rear turret machinegun, the introduction of a second fan to the turret to decrease the fighting compartment gasses while firing, usage of a new V-54K-IS engine with a nozzle heater, and a more advanced gearbox with an oil pump and an oil cooling system.
The crew layout remained the same, a driver, a commander, a loader, and a gunner. The driver was located in the bow of the vehicle, the gunner and commander in the fighting compartment to the left of the gun, and the loader to the right of the gun. Behind the fighting compartment, isolated by an engine partition, was located the engine compartment, which included the engine and all the servicing systems. Behind it, was the transmission compartment.
In the tanks with a straight cast or welded frontal hull, for the convenience of operation during combat conditions, a cutout was made in the upper sheet behind the armor of the viewing slit, where a viewing device was located. It could be fixed in two positions, upper and lower, and for cleaning from snow, dust, and dirt, it was equipped with a special wiper. This viewing device made it possible to reduce the unobservable space in front of the tank from 10 - 12 m to 4 - 5 m and increase the horizontal viewing sector from 40 degrees to 60 degrees. When driving at night, a TVN-2 night sight was mounted instead of it.
In tanks with a stepped cast bow which had a driver's hatch, a glass block with an armored shutter was installed. When driving at night, a BVN night sight was mounted instead of that unit in the observation hatch.
In the commander's turret, the MK-4 viewing device was replaced with the TPK-1 device, and the viewing slots among its perimeter were equipped with glass blocks with armored shutters.
The tank was armed with a 122mm D-25T rifled cannon, two 7,62mm DTM machine guns, and a 12,7mm DShKM anti-aircraft machine gun on a turret mount (it was not installed on all vehicles). When firing, a TSh-17 telescopic hinge sight was used which had a 4x magnification. A passing link was introduced into the elevation mechanism of the gun which protected it from breakdowns. It provided vertical aiming angles of -3 degrees to +20 degrees and was interchangeable with the analogous mechanism of the IS-2. The range of a direct shot with an AP projectile at a 2 m tall target was 1000 m, with the TSh-17 sight being able to range until 5000 m. A vernier was introduced to count the angles of horizontal aiming with an accuracy of one-thousandth of the divisions of the angle gauge. The combat rate of fire did not exceed 2 - 3 rounds/min. When firing from the DShKM, the K10-T collimator sight was used, with vertical aiming angles ranging from -5 degrees to +85 degrees, and 360 degrees horizontally. The tank's ammunition included 35 separate cartridge-loaded shots and 2331 cartridges (37 discs) for the DTM machine guns. When the DShKM was installed, the DTM ammunition was reduced to 2000 rounds, with the DShKM having 300 rounds (five tapes of 50 rounds in five box magazines, and 50 spares). In addition, the tank contained two 7,62mm AKS (since 1953, instead of PPSh-41) with 600 rounds (12 magazines of 30 rounds and 240 rounds spare), 20 F-1 hand grenades, and a SPSh-44 signal pistol with two sets of signal cartridges (20 pcs.).
The armour protection had not undergone any changes. The hull was made of cast and rolled armour with a thickness of 20mm, 30mm, 60mm, 90mm, 100mm and 120mm. The 1943 model hull was cast of high-hardness armour steel with a thickness of 60mm to 120mm. The 1944 model hull was cast high hardness steel of 100mm at 60 degrees at the upper plate and 130mm at 30 degrees at the lower plate. The upper and lower plates of the straight nose of the welded structure were made of rolled medium-hardness armour and were 90mm thick at 60 degrees and 30 degrees respectively. The upper 13-15 degree inclined and lower vertical side plates of the hull had a thickness of 90mm, the rear plates 60mm at an angle of 49 degrees for the upper and middle plate, and 41 degrees for the lower plate. The roof thickness reached 30mm and the bottom 20mm.
On the upper frontal plate, the headlights and horn were installed, as well as two brackets for attaching a bar to prevent the driver's viewport from getting splashed with mud and snow. Side mud flaps were attached to the overhanging shelves, and boxes for storing spare parts were welded to those shelves and the side plates.
A cutout was made under the lower crankcase of the gearbox to prevent it from impacting the bottom of the hull due to the lack of an 8mm gap. The gap was closed with a welded plate made of steel and it measured 715x500mm and was 20mm thick, which included two holes for access to the drain plug and gearbox lock drive. In 1954 there were additional reinforcements added under the gearbox by welding a 16-20mm thick armour plate. Another addition was a reinforced engine stand.
The cast turret with a welded roof was made out of high-hardness armour steel with a frontal thickness of 100mm. Instead of the rear machine gun, a fan was installed for reducing the fighting compartment gas buildup. To lock the turret, a pin stopper was introduced.
To extinguish fires in the tank, an OU-2 manual CO2 fire extinguisher was used installed on the left side of the turret. The MDSh smoke bomb barrels were replaced with electric fuse BDSh-5s with remote control detonation.
The V-54K-IS engine that was installed with a 519.4HP power at a crankshaft rotation speed of 2000 rpm/min, was a production diesel V-54 in which the water pump design changed and a torsion roller was installed in the oil pump drive. The height of the engine was reduced due to these pump differences. To start the engine, an 15HP ST-700 electric starter was used, and as an alternate method, two five-litre air cylinders could be used. In order to facilitate the engine start in low-temperature conditions, a NIKS-1 injection heater with a low-temperature evaporative combustion chamber was used, located in the main compartment. The IS-2M's produced before the second half of 1959 used a heating system with parallel switching oil tank heat exchanger, engine, and radiators, and on later vehicles, a sequential heating system with higher efficiency in which the oil tank heat exchanger and engine were connected in series. Since the discharged fuel from the crankcase of the fuel pump into the crankcase of the engine liquified and polluted the oil, a special tank was installed to collect it below the right air cleaner.
The tank had enough fuel reserve for 340km on the highway. After 1962, two additional 200-litre barrels were installed, increasing the distance to 490km.
The air purification system used two VTI-2 air purifiers with dust ejection and two stages of air purification. The ejection devices for the dust from dust collectors were installed instead of exhaust pipes. The service life of an air purifier without maintenance with heavy dust was increased from 50km to 400km. The lubrication system was also modernized by installing a reduction valve instead of a gear valve, which turned off the oil cooler when the temperature was low. The system also used an MZN-2 electric oil pump with a heated crankcase and a Kimaf-STZ oil filter combining wire slits and cardboard filter elements. To store the oil, an additional 35-litre tank was introduced located in the nose of the vehicle on the left overhanging shelf.
The transmission used the main clutch from the IS-3 and a gearbox with an oil pump and an oil cooling system. The oil pump provided oil into two oil radiators with a capacity of 1 litre and a cooling surface of 0.9m² above the water radiators of the engine cooling system, which were blown by the fan airflow.
The gearbox alignment with the engine due to insufficient rigidity of the bottom of the housing was eliminated by fixing the front support of the transmission box on brackets welded to the sides of the housing. The rear transmission support was made according to the type used in the IS-3 tank.
The suspension used new guide wheel cranks, support rollers and guide wheels with ball and roller bearings instead of tapered roller bearings which required adjustment of axial backlash after 500-600km. The cast iron bushings of the balancers were replaced with textolite ones and a lubrication point was introduced for the guide wheel axis cranks.
The tank's electrical equipment, in addition to the ST-700 starter, included MV-42 electric motors for the additional turret fan, MPB-3 heater boiler drive and a VM-43 oil pump, a second FG-10 headlight or FG-100 with a blackout device, an external engine starter socket, an electric reset and fuse for the BDSh-5. The control and measuring instruments were also replaced, TEM-15 pressure gauge, TUE-48T thermometer, TE-3 tachometer, GST-49 headlights and marker lights, all of which were shared with the T-54 devices. Four 6STEN-140M batteries were placed along the sides in the fighting compartment in two groups, connected in parallel and the two groups connected in series. The total capacity of the batteries was 280 Ah. For external communication, the R-113 radio station was used instead of 10RK-26, and for internal communication the TPU R-120 tank intercom instead of TPU-4-F. For IS-2MKs, the R-112 radio station and charging unit were installed in addition to the rest. The spare parts layout was also changed, now they included three sapper shovels, a hoe-pickaxe, and manual and electric MZA-3 fuel and oil filling pumps. The fastening of the covering tarp was moved from the left front wing to the rear of the turret and the log was fixed on the right side. The number of spare tracks was reduced to four.
Like with the IS-3M tank, the OGK ChTZ developed an experimental set of IS-2Ms with OPVT prototypes being made, however by order of the Council of Ministers of the SSSZ, the factory ceased any further work into that direction.
Variants[]
|
 Soviet UnionLand Vehicles Cold War Period (1946 — 1990) |
|---|
| Tracked Vehicles | ||
|---|---|---|
| Light Tanks | Light Tank | 2S25 (M) • T-54 • T-100 |
| Light Tank, Amphibious | Ob. 101 • Ob. 685 • Ob. 740 • Ob. 906 K-90 • PT-76 (A, B, M) • PT-85 • PT-90 • R-39 | |
| Light Tank, Amphibious Command | PT-76K | |
| IFV | Ob. 19 • Ob. 911 • Ob. 914 B-10 • B-19 • BMP-64 • BMPT • BMPV-64 | |
| IFV, Amphibious | Ob. 765 (Sp.1 • Sp.2 • Sp.3 • Sp.4 • Sp.8) • Ob. 911 BMP-1 (1966 • 1969 • 1973 • 1979 • P • PG) • BMP-2 (D • M) • BMP-3 (F • FK • Fr • K • M • M-3) | |
| Medium Tanks | MBT | Ob. 139 • Ob. 140 • Ob. 167 (T) • Ob. 430 (U) • Ob. 450 • Ob. 640 • Ob. 785 T-54 • T-55 (64) • T-62 (1960, 1972, 1975, D, D-1, K, KN, M, M-1, M1, M1-1, M1-2, M1-2-1, M1V, M1V-1, MD, MD-1, MK, MK-1, MV-1) • T-64 (A, AK, B, B1, B1M, BM2, BV, R, T, U) • T-67 • T-72 (A 1979 • A 1984 • AK • AV • B • B 1989 • B 1990 • B1 • B2 • B3 2011 • B3 2014 • B3 2016 • T-72B3M • BA • BU • BV • M • M1 • M1M • M1V • S • V) • T-74 • T-80 (A 1982 • A 1984 • AK • AKV • B 1978 • B 1980 • BK • BV 1985 • BVK • BVM 2017 • M-1 • U 1986 • U 1992 • UE 1999 • UK • UM 1995 • UM-1 1997 • UM-2 • UM2) • T-90 (1992 • A 2006 • AK • AM • K • M 2017 • MS • S • SK) • T-95 • T-99 |
| Command Tanks | 446B • T-64B1K • T-64BK • T-72 (AK • B1K • BK • K • M1K • MK) • T-90 (K) | |
| Flamethrowing | OT-54 (B) • OT-55 • OT-62 | |
| Heavy Tanks | Heavy Tank | Ob. 240 (M) Ob. 277 • Ob. 279 • Ob. 770 IS-2 (M • MK) • IS-3 (M) • IS-4 (M) • IS-7 • IS-8 • T-10 |
| SPG | ATGMV | Ob. 150 • Ob. 287 IT-1 |
| SPAA | Ob. 119 • Ob. 500 • Ob. 575 2S6 (M • M1) • 2S38 • 9K35 • 9K37 • 9K330 • PT-76B with 9M14 • S-300 • ZSU-23-4 (V • V1, M1 • M2 • M3 • M4 • M5) • ZSU-37-2 • ZSU-57-2 | |
| SPATG | Ob. 120 2S15 • 2S25 (M1) • 2S28 • 2S29 • 2S37 • ASU-57 • ASU-76 • ASU-85 • BTR-50P • SU-85M • SU-100 • SU-122-54 | |
| SPG | 2S1M • 2S5 (M • M1) • 2S7 (M) • 2S9 (-1 • 1M) • 2S11 • 2S13 • 2S17 (-2) • 2S22 • 2S23 (M) • 2S31 (Ye • M) • 2S34 (-1 • M) • 2S36 • 2S39 • 2S40 • 2S42 • 2S43 • ISU-152 • Obzhimka • T-62/160 | |
| SPH | 924 • 2A3 • 2A4 • 2S1 (M1) • 2S2 • 2S3 (M • M1, M2 • M2-155 • M3) • 2S18 • 2S19 (M • M1 • M1-155 • M2) • 2S21 • 2S26 • 2S27 • 2S30 • 2S33 • S-103 | |
| Self-Propelled Laser | 1K17 Szhatie | |
| SPM | 2S4 • 2S8 • 2S10 • 2S12 (A • B) • 2S24 • 2S41 | |
| SPRA | 2P16 • 9P139 • BM-24T • Object 280 • Object 634 (B) • TOS-1 • TOS-1M (A) | |
| Explosive Related | Mine Laying | GMZ-3 |
| Mine Clearing / Sweeping | BMR-3 • BMR-3M (A) • UR-07 • UR-67 • UR-77 | |
| Misc Tanks | Ammunition Carrier | TZM-T |
| APC | BTR-50 • BTR-50PA • BTR-50PM • BTRV-64 • R-40 | |
| ARV | BREM-1 (M) • BREM-64 • BREM-L • Object 447T • BTS-4V • T-62T | |
| Bridge Laying | MTU-72 • MTU-90 | |
| Command | Ob. 773 (P) • Ob. 774 BMP-1 (K • KSh • PK) • BTR-50PN • BTR-50PU • BTR-50PU-2 • BTR-50PUM • BTR-50PUM-1 | |
| Engineering & Maintenance | BAT-2 • BMT-3 • BTM-4 • IMR-2 • IMR-3M • IRM • MDK-3 • MTP-1 • ZSU-57-2 BTS-55 | |
| Firefighting | SPM | |
| Observation, Spotting & Survey | Ob. 767 • Ob. 779 (M) PRP-3 • PRP-4 (M • MU) | |
| Reconnaissance | PT-76RKh | |
| Transport & Towing | BMO-T • IT-1T | |
| Wheeled Vehicles | ||
|---|---|---|
| Offensive / Defensive | IFV | BMPT-K-64 • VPK-7829 • Object 19 |
| SPAA | 9P31 • BTR-40A • BTR-141A | |
| SPATGM | 2P27 • 2P32 • 9P110 • 9P122 • 9P124 • 9P133 • 9P137 • 9P148 | |
| SPBM | 9P71 • 9P117 • 9P120 | |
| SPH | 2S27 • A-222 | |
| SPRA | 2B5 • 2B17 • 2B26 | |
| Other | APC | BTR-40 (V • B • B (RKh) • ZhD) • BTR-60 (P • PA • PB • PBM) • BTR-70 • BTR-80 • BTR-90 • BTR-141 • BTR-7829 • GAZ-3937-11 |
| ARV | BREM-K | |
| Bridge Laying | PP-2005 • PPS-84 • TMM-3 • TMM-6 | |
| Cargo | GAZ-33097 • KamAZ-5350 • KamAZ-6350 • KamAZ-43501 • MAZ-4370 • MAZ-4570 • MAZ-5336 • MAZ-5337 • MAZ-5432 • MAZ-5433 • MAZ-5434 • MAZ-5442 • MAZ-5516 • MAZ-5551 • MAZ-6303 • MAZ-6317 • MAZ-6417 • MAZ-6422 • MAZ-6425 • MAZ-6430 • Ural-4320 • Ural-5323 • Ural-43206 • ZiL-4334 | |
| CP | GA-39371 | |
| Crane | KS-5571 • KS-5573 • KS-5576 • KS-6571 | |
| Decontamination Vehicle | ARS-14KM • TMS-65 • USSO | |
| Dump Truck | MAZ-7510 | |
| Engineering | EOV-3521 • EOV-3523 • KamAZ-65225 • KS-3574M3 • MAZ-205 • MAZ-500 (A, SH) • MAZ-501 • MAZ-503 (A) • MAZ-509A • MAZ-510 • MAZ-511 • MAZ-516B • MAZ-525 • MAZ-529 • MAZ-530 • MAZ-5335 • MAZ-5334 • MAZ-5549 • MAZ-53352 • PBU-100 | |
| Firefighting Vehicle | AA-60(543)-160 • AA-70(543)-172 • AA-60(7310)-160.01 • AA-60(7313) (160.01 • AA-60(7313)-220) | |
| IMV | GAZ-2975 • GAZ-3937 • GAZ-3937-10 • GAZ-233034 • GAZ-233036 • Iveco LMV | |
| Medical | BMM-80 | |
| RV | BPM-97 • BRDM-1 (RKh • U) • BRDM-2 (RKh • RKhA • RKhB • U) | |
| Security | Lavina-M | |
| Smoke Generating Vehicle | TDA-2K • TDA-3 | |
| Transport & Towing | 9T254 • MAZ-200 (V) • MAZ-502 • MAZ-504 (A • B • G, S • V) • MAZ-508B • MAZ-520 • MAZ-535 (A) • MAZ-5429 • MAZ-7310 • MAZ-7904 • MAZ-7906 • MAZ-79221 • NAMI-020 • NAMI-021 • Ural-375 • ZiL-131 | |
| Utility | MAZ-543 (A, M, P) • MAZ-547 • MAZ-7907 • MAZ-7910 • MAZ-7912 • MAZ-7917 • MAZ-74106 • UAZ-452 • UAZ-469 • UAZ-3132 • UAZ-3163 | |
| Sources | ||
|---|---|---|
| Books | Online | Documents |
| Отечественные Бронированные Машины 1945-1965 гг. - Часть 1 - Легкие, средние и тяжелые танки, М. В. Павлов, И. В. Павлов (ISBN 978-5-85905-623-1) | ||