IS-1 (tank)

IS-1
	Prototype of the IS-1
General properties
crew	4th
length	8.56 m
width	3.07 m
height	2.73 m
Dimensions	44 t
	Armor and armament
Armor	20 to 120 mm
Main armament	85 mm L / 51.6 gun D-5T85
Secondary armament	1 × MG 7.62 mm Degtjarjow DT coaxial ; 1 × MG 7.62 mm DT in the turret rear ; 1 × bow MG 7.62 mm DT (rigid)
agility
drive	12-cylinder diesel engine W-2 IS ; 520 HP
suspension	Torsion bar suspension
Top speed	40 km / h
Power / weight	11.8 hp / t
Range	150 km

The IS-1 (from I ossif S talin; German Josef Stalin ) was a heavy Soviet tank in World War II .

history

The first model of the IS series was developed further from the KW series . A new heavy tank should avoid the disadvantages of its predecessor, get stronger armor with lower weight and stronger main armament.

KW-13

From the end of 1941, the special design office No. 2 in the Chelyabinsk tractor factory worked on a further development of the KW-1 , the medium tank KW-13 (Object 233). The new tank was supposed to combine the mobility of the T-34 with the level of protection of the KW. The first prototypes were tested in March 1942, the model was not put into series production due to reliability problems as well as the two-man turret and insufficient armor protection. The KW-13 was armed with the 76.2 mm SiS-5 cannon in the tower of the KW-1 and had a support roller drive with five rollers on each side.

KW-1S

The immediate forerunner of the IS-1 was the KW-1S , which differed from the KW-1 through a smaller, cast turret, an improved gearbox and modified hull armor, which - with the same degree of protection - weighed five tons less. From 1942 to 1943, 1230 pieces of the KW-1S were produced. It formed the basis for the KW-85.

development

The IS-1 (Object 237) was developed as IS-85 by SKB No. 2 under the direction of Josef Jakowlewitsch Kotin in Chelyabinsk from spring 1942 . Various technical solutions developed for the KW-13 were implemented in the tank. Due to the criticism of the KW-13 and the appearance of the Pz VI "Tiger" , a more spacious three-man turret with an 85 mm cannon was developed for the IS-85 and the originally used solution from the KW-13 with two-man turret and 76.2 -mm cannon discarded again. The two 85 mm S-31 and D-5T cannons were compared as the main armament. The S-31 was an experimental cannon that combined the 85 mm barrel with the bottom piece of the 76.2 mm SiS-5 cannon . The D-5T was characterized by its low weight and low recoil. Both cannons could not be installed in the tower of the KW-13. The three-man turret, in turn, forced the hull to be extended by 420 mm, which made a sixth roller necessary so that the drive again largely corresponded to that of the KW series tanks. In the end, the weight increased to an acceptable 44 t. Compared to the KW-1S, the ground pressure increased from 0.74 to 0.78 kg / cm², speed and range were lower.

KW-85

At the same time as the development of the IS-85, the Chelyabinsk Tractor Plant, parallel to the serial production of the KW-1S, developed two combat value enhancements for it to cushion the delays in the development of the IS-85 until it was ready for series production - Object 238 with an S-31 cannon in the unmodified one Series turret and Object 239 with the D-5T in the tower of the IS-85 (Object 237). Both prototypes had the series hull of the KW-1S.

Comparison tests

Object 238 and Object 239 were subjected to comparative tests together with the two prototypes of the IS-85 in July 1943. As a result of these tests, Object 238 was discarded and Object 237 was designated IS-85 and Object 239 was KW-85 .

On August 2, 1943, further tests were carried out with the IS-85 and the KW-85 in Kubinka and Gorochowezki. The acceptance committee recommended both models for series production. The new tanks were then presented to the Soviet leadership in the Kremlin on August 8, 1943.

production

Series production began immediately after testing. 67 units had been built by January 1944. Production of the successor model IS-122 began in December 1943; from February 1944 only the IS-122 was manufactured. As of March 1944, the IS-85 was officially designated as the IS-1 and the IS-122 as the IS-2 .

Remaining stocks of IS-1 have already been converted at the factory to the turret of the IS-2 with the 122 mm D-25T cannon. Vehicles salvaged from the battlefield and brought to the factory for factory repairs were also converted and returned to the troops as IS-2s.

construction

Tub and drive

The IS-1 has a bullet-resistant shell made of cast armored steel. The tub partly protrudes over the rollers, which made it possible to install the larger tower. The tower is also made of cast armored steel. The new IS tank was about 3.5 t lighter than the KW-1 and performed better; the decisive improvement, however, concerned the hull, which had a much stronger armor while being lighter.

The IS-1 has a support roller drive with torsion bar suspension. External rubber buffers serve as spring travel limiters. It has six rollers and three support rollers on each side of the vehicle. The guide rollers are located at the bow, the drive rollers at the rear of the vehicle. All rollers are cast, running and guide rollers are identical and interchangeable. The guide rollers guide and tension the crawler tracks in conjunction with the chain tensioning cam. The crawler tracks each have 86 chain links, every second of which has a guide lug. The two sprockets of the drive rollers each grip into windows on the sides of the chain links.

drive

The IS received the further developed W-2-10 diesel engine (W-2-IS) with an output of 520 hp. The engine is installed lengthways and has an additional flywheel starter, the engine suspension has been improved. The torque is transmitted to the countershaft or the gearbox via a multi-disc dry clutch. The gearbox has four forward and one reverse gears; In connection with the back gear, eight gear ratios can be used. The total reduction is 13: 1. The steering gears are designed as planetary gears, which saves 18 cm of tub width compared to the KW-1S.

Armament

The main armament of the IS-1 is the 85-mm cannon D-5T85, a variant of the 85-mm cannon D-5S of the SU-85 , for which 59 shell cartridges were carried. Three Degtjarjow MG DT in caliber 7.62 × 54 mm R serve as secondary armament . A MG is rigidly built into the tub to the right of the driver and is electrically operated by the driver. The entire vehicle is judged. Another machine gun is installed coaxially to the right of the cannon in the turret; it is operated by the gunner. The third MG is used for self-defense and is installed in a spherical screen on the left in the rear of the turret behind the commander's seat.

Armor

The armor consists of cast armor steel plates and molded parts of different thicknesses. The penetration depth is increased by inclining the armor plates. The most heavily armored areas are the front plate with 120 mm and the tower front wall with 100 mm. The armor tended to shatter on the rear even if hit non-penetratingly. The steel fragments often wounded or killed the crew.

Although shaped to repel bullets, the hull had a weak point: the step in front of the driver's hatch and the hatch itself. Enemy tank or PaK crews tried to hit this point preferably, and many IS-1s were hit by shell impacts ( 7.5 cm or 8 , 8 cm ) incapacitated in this area. This problem was later corrected in the IS-2, model 1944 ( IS-2II ) by a modified front plate without a step and without a driver's hatch.

Observation devices

The main rifle scope of the IS-1 is the 10T-15 with 2.5x magnification. There was also a PT-4-15 panoramic rifle scope and a PU rifle scope for the rear MG. The commander, loader and gunner each had a corner mirror No. 4 . A commander's cupola was available to the commander.

Radio equipment

The IS-1 were equipped with the 10-RK-26 radio station.

crew

The crew of the IS-1 consisted of four soldiers: commander, driver, gunner and loader. The driver sat centrally in the bow of the vehicle, the gunner at the front left, the commander at the back left in the turret. The loader had his place to the right of the cannon in the turret.

Technical specifications

Designation : Josef Stalin IS-1
Classification : heavy tank
Weight
- Combat weight: 44 t
- Ground pressure : 0.78 kg / cm²
Dimensions
- Length over everything with pipe to the front: 8.56 m
- Length of the tub: 6.77 m
- Width overall: 3.07 m
- Height: 2,735 m
- Ground clearance: 0.465 m
- Pipe overhang with pipe to the front: 1.60 m
drive
- engine
  - Type: W-2-10 (W-2-IS)
  - Design: 12-cylinder four-stroke diesel engine (60 ° V-shape), water-cooled
  - Displacement: 38,880 cm³ (38.9 l)
  - Output: 520 hp at 2000 rpm
  - Installation position: mid-engine, lengthways
- transmission
  - Type: mechanical four-speed gearbox
  - Number of forward gears: 4
  - Number of reverse gears: 1
  - Additional gear: 2
  - Drive type: Drive on one rear idler on each side
steering
- Two-wheel planetary steering gear, operated by two steering levers
- Installation position: in the rear behind the engine
- Turning circle: on the spot
landing gear
- Design: support roller drive, six steel rollers, three support rollers, rear drive wheel, front guide wheel
- Suspension: torsion bar suspension with transverse torsion bars
- Chain width: 65 cm
- Track width: 2.45 m
- Chain type: dry
- Chain division: 86 links
- Chain contact area: 4.36 m
Performance
- Maximum road speed: 40 km / h
- Top speed terrain: 19 km / h
- Power-to-weight ratio : 11.8 hp / t
- Gradeability: 36 °
- Climbing ability: 1.00 m
- Wading ability: 1.30 m
- Trench crossing ability: 2.5 m
- Road fuel consumption: 280–330 l / 100 km
- Off-road fuel consumption: 330–450 l / 100 km
- Driving range road: 150 km
- Off-road driving range: 120 km
- Fuel supply: 500 l + 360 l in external disposable containers (1 container for 90 l engine oil)
Armament
- Main gun: 85 mm L / 51.6 D-5T85 cannon
  - Muzzle velocity: 792 m / s
  - Barrel weight with lock and muzzle brake: 1500 kg
  - Tube length with muzzle brake: 4.386 m
  - Elevation field: −4 ° to + 23 °
- Secondary armament
  - 1 × MG 7.62 mm Degtjarjow DT coaxial in the turret
  - 1 × MG 7.62 mm Degtjarjow DT in the turret rear
  - 1 × MG 7.62 mm Degtjarjow DT in the hull bow
- Target means
  - Telescopic rifle scope 10T-15, panoramic rifle scope PT-4-15
- ammunition
  - Cannon: 59 rounds (40 tank shells + 19 HE shells), stored in the tower
  - MGs: 2520 rounds
Crew : 4 men
Tower drive : hydraulic
Armor
- Tub
  - Bow 100 mm / 60 °
  - Inclined surface between the bow and the front of the driver: 60 mm / 18 °
  - Driver front 120 mm / 60 °
  - Side up 90 mm / 75 °
  - Side down 90 mm / 90 °
  - Upper rear 60 mm / 41 °
  - Rear bottom 60 mm / 49 °
  - Ceiling 30 mm / 0 °
  - Front floor 30 mm / 0 °
  - Rear floor 20 mm / 0 °
- tower
  - Aperture 100 mm / round
  - Front 100 mm / round
  - Side 100 mm / 72 °
  - Stern 100 mm / 60 °
  - Top 30 mm / 0-5 °
Manufacturer : Factory No. 100 in Chelyabinsk (TschTS, Kirowwerk or Tankograd)
Number of pieces : 67

commitment

The IS-1 was supposed to replace the KW tanks in all Soviet "heavy breakthrough tank units". These newly formed units were referred to as "Guard armored units" to emphasize their importance. The first missions took place in early 1944 in offensives in the Ukraine , but the IS-1 was not particularly successful against panthers and tigers. Numerous operational and tactical errors during use did not allow the new tank to play all its trump cards and favored the German Wehrmacht , who were already fighting on the defensive and which managed to shoot down many of the new tanks relatively easily.

One of the first deployments of the IS-1 (with 21 tanks) on February 15, 1944 near the village of Lisjanka was a failure, as all the Soviet tanks involved, including the IS-1, were shot down by panthers and assault guns camouflaged in the village. The tanks received an average of seven hits. The village was not captured until the next day after the German tanks ran out of fuel.

On several occasions on March 8, 1944, first two, later more IS -1s were destroyed by 7.5 cm PaK 40s . Overall, the PaK 40 was the undoing of many IS-1s in 1944.

During a mission on March 15, 1944 near Uman , five IS- 1s were destroyed by 8.8 cm anti-aircraft guns , three tanks failed due to technical problems. A rare occurrence occurred: The lower bow armor was penetrated by a shot from a heavy anti-tank rifle 41 .

The first confirmed encounter with the Tiger ( heavy tank division 503) took place on March 4, 1944 near Staro-Konstantinow, an IS-1 was shot down from a distance of 1500 to 1800 m, others were destroyed and others were badly damaged. The IS-1 managed to severely damage a Tiger on the drive. Another skirmish with a tiger on March 16, 1944 ended similarly, two IS-1s were destroyed and burned down with their crews, the others were badly damaged or shot unable to move.

literature

AW Karpenko: Soviet-Russian tanks . 1905-2003. Elbe-Dnjepr, Klitzschen 2004, ISBN 3-933395-44-5 , p. 418-419 (Russian: Обозрение отечественной бронетанковой техники (1905-1995 гг.) . Translated by R. Meier).

Individual evidence

↑ ^a ^b The KV-13 program. In: Iosif Stalin 1 (IS-1). tanks-encyclopedia.com, accessed June 24, 2014 .
^ Soviet Union's IS-85, IS-1, JS-1 heavy tank. wwiivehicles.com, accessed June 24, 2014 .
↑ KV-13 prototype. In: Soviet Union's KV-1 (Kliment Voroshilov) heavy tank. wwiivehicles.com, accessed on June 24, 2014 (photo of the KW-13 prototype).
↑ AW Karpenko: Soviet-Russian tanks . 1905-2003. Elbe-Dnjepr, Klitzschen 2004, ISBN 3-933395-44-5 , p. 258, 405 (Russian: Обозрение отечественной бронетанковой техники (1905–1995 гг.) . Translated by R. Meier).
↑ AW Karpenko: Soviet-Russian tanks . 1905-2003. Elbe-Dnjepr, Klitzschen 2004, ISBN 3-933395-44-5 , p. 410–411 (Russian: Обозрение отечественной бронетанковой техники (1905–1995 гг.) . Translated by R. Meier).
↑ ^a ^b ^c ^d ^e ^f ^g ^h Valeri Potapow: JS-1 and JS-2 Heavy Tanks. battlefield.ru, September 18, 2011, accessed June 24, 2014 .
↑ ^a ^b Josef Stalin. The heavy Soviet battle tanks. WaffenHQ, accessed June 24, 2014 .
↑ ^a ^b ^c ^d ^e ^f ^g ^h ⁱ ^j ^k ^l ^m ⁿ ^o ^p ^q ^r ^s ^t ^u ^v ^w ^x ^y ^z ^aa ^ab ^ac A. W. Karpenko: Soviet-Russian tanks . 1905-2003. Elbe-Dnjepr, Klitzschen 2004, ISBN 3-933395-44-5 , p. 410, 418 (Russian: Обозрение отечественной бронетанковой техники (1905–1995 гг.) . Translated by R. Meier).
↑ ^a ^b Jörg Siegert , Helmut Hanske: Main battle tanks of the NVA . Motorbuch, Stuttgart 2011, ISBN 978-3-613-03294-1 , The heavy tank IS-2, p. 55–69 (tub and drive are identical to the IS-2.).

Web links

Commons : IS-1 - Collection of Images

Valery Potapov: JS-1 and JS-2 Heavy Tanks. battlefield.ru, September 18, 2011, accessed June 24, 2014 .

[tanks-encyclopedia-1] The KV-13 program. In: Iosif Stalin 1 (IS-1). tanks-encyclopedia.com, accessed June 24, 2014 .

[2] Soviet Union's IS-85, IS-1, JS-1 heavy tank. wwiivehicles.com, accessed June 24, 2014 .

[3] KV-13 prototype. In: Soviet Union's KV-1 (Kliment Voroshilov) heavy tank. wwiivehicles.com, accessed on June 24, 2014 (photo of the KW-13 prototype).

[4] AW Karpenko: Soviet-Russian tanks . 1905-2003. Elbe-Dnjepr, Klitzschen 2004, ISBN 3-933395-44-5 , p. 258, 405 (Russian: Обозрение отечественной бронетанковой техники (1905–1995 гг.) . Translated by R. Meier).

[5] AW Karpenko: Soviet-Russian tanks . 1905-2003. Elbe-Dnjepr, Klitzschen 2004, ISBN 3-933395-44-5 , p. 410–411 (Russian: Обозрение отечественной бронетанковой техники (1905–1995 гг.) . Translated by R. Meier).

[battlefieldru-6] ↑ ^a ^b ^c ^d ^e ^f ^g ^h Valeri Potapow: JS-1 and JS-2 Heavy Tanks. battlefield.ru, September 18, 2011, accessed June 24, 2014 .

[Waffenhq-7] Josef Stalin. The heavy Soviet battle tanks. WaffenHQ, accessed June 24, 2014 .

[Karpenko85-8] ↑ ^a ^b ^c ^d ^e ^f ^g ^h ⁱ ^j ^k ^l ^m ⁿ ^o ^p ^q ^r ^s ^t ^u ^v ^w ^x ^y ^z ^aa ^ab ^ac A. W. Karpenko: Soviet-Russian tanks . 1905-2003. Elbe-Dnjepr, Klitzschen 2004, ISBN 3-933395-44-5 , p. 410, 418 (Russian: Обозрение отечественной бронетанковой техники (1905–1995 гг.) . Translated by R. Meier).

[KPz_NVA-9] Jörg Siegert , Helmut Hanske: Main battle tanks of the NVA . Motorbuch, Stuttgart 2011, ISBN 978-3-613-03294-1 , The heavy tank IS-2, p. 55–69 (tub and drive are identical to the IS-2.).