Object 279: Experimental heavy tank of the Soviet Union

The Object 279 is a Soviet experimental heavy tank developed between 1955 and 1959 at the Experimental Design Bureau of Transport Engineering of the Leningrad Kirov Plant (OKBT LKZ) under the leadership of the distinguished designer Joseph Yakovlevich Kotin. This project was conceived as a special-purpose vehicle capable of penetrating deeply echeloned enemy defenses, operating in conditions of radiation contamination after a nuclear strike, and traversing difficult terrain such as swamps, deep snow, boulders, and dragon's teeth. The Object 279 featured a unique four-track chassis, a one-piece cast hull with a complex teardrop shape, providing maximum protection due to its sloping surfaces, and a powerful 130mm M-65 rifled gun, capable of engaging any contemporary target at long ranges. Four prototypes were built and underwent extensive testing in 1960–1961 at the NIIBT Polygon and in Leningrad, demonstrating outstanding performance. However, the project was not put into serial production due to doctrinal changes in military strategy, a test accident, and a preference for more versatile main battle tanks (MBT). Object 279 became the pinnacle of Soviet heavy tank design during the Cold War, embodying bold innovations decades ahead of their time and significantly influencing the development of armor, cross-country capability, and automation concepts in subsequent tank generations, such as the T-64, T-72, and even future platforms like the T-14 Armata.

Background and creation

In the mid-1950s, the Soviet Union, at the height of the Cold War with the United States and NATO, was actively reequipping its armored forces, taking into account the lessons of World War II and the early signs of the nuclear age. Heavy tank development continued despite the transition to medium models like the T-54/55, as intelligence pointed to potential threats from the American heavy M47 Patton and the advanced M103, as well as the British Centurion Mk.5 with their enhanced armor and 105mm guns. The Korean War (1950–1953) demonstrated that tanks must withstand not only kinetic energy projectiles but also shaped-charge warheads, as well as operate in chemical and radiation environments. In 1955, the Main Armored Directorate (GBTU) of the USSR Ministry of Defense announced a competition to create a new heavy tank (HBT) weighing up to 60 tons, armed with a gun of at least 122 mm, and focusing on breakthrough capabilities and survivability in a nuclear field. Participants included the Leningrad OKBT LKZ, led by Zh. Ya. Kotin (a veteran of the KV and IS tanks), and the Chelyabinsk OKB of the Kharkov (later Chelyabinsk) KBTM, led by A. A. Morozov (designer of the T-62). The specifications included protection against 122 mm shells at all ranges, swamp mobility (pressure <0,7 kg/cm²), automated loading, and an NBC protection system.

Development of Object 279 began in January 1957 at the LKZ Design Bureau, where L. A. Ionus was appointed lead designer, and V. V. Balanin (chassis) and L. S. Popov (weapons) became key specialists. A team of over 200 engineers, metallurgists, and testers focused on the specifics of Soviet doctrine: a breakthrough in the European theater, where swampy areas and snowdrifts were expected, as well as operations in a post-nuclear landscape. The first preliminary design was presented in December 1957: a tank with a one-piece, teardrop-shaped hull to disperse shock waves and shrapnel, four parallel tracks (two bogeys on the sides) for weight distribution and high cross-country ability, and a 130-mm gun to outperform NATO 90-105-mm guns. In 1958, a wooden mockup and experimental cast hull sections were produced and tested on a ballistic rig: the armor withstood a 122mm APFSDS round at 500 meters. In 1959, the Kirov Plant assembled the first prototype (No. 1) for road trials, equipped with an engine and transmission, but without full electronics. The second and third prototypes (Nos. 2–3) were intended for firing tests with a full turret and fire control system, while the fourth (No. 4) served as a spare for modifications.

Factory trials of the first prototype took place in Leningrad in May–June 1960: the tank covered 500 km over mixed terrain, including marshy testing grounds near Pushkin, demonstrating its cross-country capability (moving on three tracks with one broken). State trials at the NIIBT Polygon (Kubinka) in August–October 1960 and January–March 1961 included a 2000 km road course, 500 rounds of live fire, ballistics (90% hit rate at 2 km), and maneuvers. The prototypes demonstrated superior performance: a speed of 55 km/h, protection against 122 mm shells on the frontal projection, and a low pressure of 0,6 kg/cm². However, on October 29, 1961, during night tests at a speed of 55 km/h, prototype #3 overturned on a turn due to its high center of gravity and the drag of four tracks, resulting in the deaths of the crew and injuries. This accident, along with criticism from N. S. Khrushchev (a favorite of the missile forces) regarding the "obsolete" heavy tanks, led to the project's closure. By a decree of the Central Committee of the CPSU and the Council of Ministers of the USSR dated January 28, 1961, the Chelyabinsk Object 280 won the competition (it lost in cross-country performance), but soon all heavy projects were abandoned in favor of the T-62 OMBT. Object 279 documentation was archived, and the prototypes were mothballed: #1 and #2 in the Kubinka hangars (#1 was later restored for static display), #3 was restored after repairs, and #4 was dismantled for spare parts. LKZ's resources were redirected to the production of the T-10M and the development of the T-64, where the ideas of the 279th were reflected in the sloped armor and autoloaders.

Design and specifications

Object 279 was designed as a heavy breakthrough tank with an emphasis on absolute impenetrability, extreme cross-country ability, and partial automation to minimize crew vulnerabilities in a nuclear conflict. The hull was a single-piece cast structure made of high-alloy steel (120–270 mm thick), made in a teardrop shape with radical slopes: the frontal part was 60–80° (equivalent to 500–700 mm for kinetic and cumulative penetration), the sides were 45–60° (182 mm), the rear was 30° (82–102 mm), and the turret was a spherical cast turret (305 mm at the front). The total hull weight was 32 tons (53% of the full weight), which was a record for casting. This shape not only increased protection (it withstood the 122mm 3BM1 BPS at 500 m and 90mm HEAT at all ranges at angles of ±45° for the hull and ±90° for the turret), but also dispersed the shock wave from a nuclear explosion. Additional measures included anti-cumulative screens on the sides (steel gratings), an anti-aerosol protection system (PAZ) with filters, anti-chemical and radiation lining (PPO/PRZ), an automatic fire extinguishing system (AFS) based on CO2, observation devices in a smoke screen (OPVT with IR filters), and cabin heating for arctic conditions. The four-track undercarriage is a unique feature: two independent bogies on the sides, each with two 500 mm wide tracks and eight road wheels (800 mm in diameter), connected by a rigid frame. This reduced the ground pressure to 0,6 kg/cm² (the same as the amphibious PT-76), allowing the vehicle to traverse 1 m deep swamps, 1,5 m deep snow, and 0,8 m deep boulders, as well as continue moving if one track breaks (the other three).

The main armament was the 130mm M-65 rifled gun (barrel length 54 calibers, muzzle velocity 950-1000 m/s), developed by OKB-172, with a muzzle energy of 15-16 megajoules—1,5 times higher than that of the 122mm D-25T IS-3. The 3BM1 armor-piercing shell had a penetration of 400-500 mm of homogeneous armor at 1-2 km, while OF-130 high-explosive fragmentation shells were used for fortifications. The drum-type autoloader in the turret niche held 42 shells (24 in the drum + 18 hand-loaded), providing a rate of fire of 7 rounds per minute without a second loader. A twin 14,5mm KPVT machine gun with 200 rounds of ammunition is used to engage air defense targets and flanking infantry. An anti-aircraft version is not envisaged, but the DShK was planned. The fire control system (FCS) was advanced for the 1960s: a DV-130 optical-mechanical rangefinder (4 km range), dual-plane stabilization, a TPN-2-130 night sight (IR amplifier, 1 km visibility), and a TG-12 commander's panoramic sight (360° field of view). Accuracy on the move is 0,2 arc seconds, with an 85% first-shot hit rate. The crew consists of four: the commander and gunner in the turret (with separate seats and monitors), the loader (automatic systems reduced the load), and the driver-mechanic in the hull. The compartments are isolated, the ergonomics are at a high level: ventilation, shock absorption, communication throughout the tank.

The engine is a medium-speed diesel 2D12-400 (V-shaped, 12 cylinders, 1000 hp at 2100 rpm), with a specific power of 16,7 hp/t. Fuel - diesel or kerosene, consumption 500 l/100 km. Maximum speed is 55 km/h on the highway, 30-40 km/h on rough terrain, acceleration to 30 km/h - 12 sec. Cruising range is 300 km (with additional tanks - 400 km). Transmission - hydromechanical with a planetary gearbox (5 speeds forward, 2 reverse), steering - rotary clutches. Suspension - individual torsion bar on each bogie, with hydraulic shock absorbers. Tracks with removable shoes for snow/swamps. The tank could negotiate gradients of up to 35°, ditches 3,5 m wide, walls 1,2 m high, and fords 1,6 m deep (with 2,2 m of active protection). Electronics included a 10-RT-26 radio (range 30 km), IR beacons for night maneuvers, and a 20 kW generator. The design was extremely complex: casting the hull took 2000–2500 hours in a furnace, and track repairs took up to 24 hours. However, it provided record-breaking protection without dynamic armor (ERA), outperforming Western counterparts by 10 years.

Specifications:

• Weight: 60 tons
• Crew: 4 people (commander, gunner, loader, driver)
• Armor: hull front - 122–269 mm (60–80° slope, equivalent to 500–700 mm KE/CE), sides - 182 mm (45°), rear - 82–102 mm, turret front - 305 mm (spherical)
• Armament: 130 mm M-65 rifled gun (42 rounds of ammunition, including 3BM1 BPS and OF-130 OFS), twin 14,5 mm KPVT machine gun (200 rounds)
• Engine: 2D12-400, diesel V12, 1000 hp (735 kW)
• Speed: up to 55 km/h (highway), up to 40 km/h (rough terrain)
• Range: ~300 km (highway, with main tanks of 680 l)
• Suspension: individual torsion bar with four tracks (500 mm wide each)
• Obstacles to be overcome: ditch - 3,5 m, wall - 1,2 m, ford - 1,6 m (2,2 m with protection), climb - 35°

Mass production never took off: prototypes were assembled by hand at the Kirov Plant using experimental casting furnaces, but calculations showed the feasibility of producing 50-100 units per year with further development. The concepts of Object 279 (automated turret, sloped cast armor) formed the basis for the T-64A (1966) and influenced the export variants of the T-55AD.

Combat application

Object 279 did not see actual combat, limiting itself to an extensive laboratory and field testing program, typical of experimental Soviet heavy tanks of the 1950s and 1960s. The first prototype (No. 1) underwent factory road tests in May and June 1960 at the Leningrad Heavy Tank Plant and adjacent testing grounds in the Leningrad Region. This included a total of 1000 km of driving on asphalt, dirt, and artificial swamps (0,8–1 m deep), where the four-track design confirmed its superiority—the tank did not sink in, unlike the T-10 (at a pressure of 0,9 kg/cm²). The engine demonstrated reliability: 200 hours of trouble-free operation, although overheating in hot weather required cooling modifications. Military observers from the Main Technical Directorate (GBTU) noted its potential for Arctic and Siberian theaters of operations, where snow and peat are the norm.

State tests of prototypes No. 2 and No. 3 in August–October 1960 at the NIIBT Polygon proving ground (Kubinka, Moscow region) included comprehensive tests: live fire (500 shots from the M-65 at shields at a distance of 1–3 km, 90% hit rate from a standstill and 85% on the move), ballistics of protection (100 hits from 122 mm BPS and cumulative shells – not a single penetration of the frontal projection) and maneuverable runs (2000 km over rough terrain, including boulders and antitank obstacles). The tank successfully stormed a "fortified area"—1-meter-thick concrete walls and water-filled ditches—demonstrating a speed of 40 km/h in 1-meter-thick snow. The NBC protection system withstood a simulated chemical attack (mustard gas, phosgene), and the TDA extinguished the "fire" in 10 seconds. The second stage, in January–March 1961, added night tests: the TPN-2-130 IR sight allowed firing in complete darkness at a range of 800 meters. Advantages: survivability (continuing combat after losing a track), and the fire control system in smoke/dust conditions (80% hit rate through the smoke curtain). Disadvantages included high rolling resistance (power output 20% higher than standard), difficulty in repair (bogie replacement takes 12–24 hours), and an accident involving prototype #3 on October 29, 1961, during a high-speed maneuver at 55 km/h (34 mph). The accident resulted in a rollover on a 15-meter-radius turn due to the inertia of the four tracks and a high center of gravity (6.8 ft), resulting in the deaths of two crew members and injuries to two others. The accident precipitated criticism: GBTU reports noted "excessive complexity" compared to Object 280.

In the context of the Berlin Crisis (June–October 1961) and the Cuban Missile Crisis (1962), Object 279 could have reinforced the Group of Soviet Forces in Germany (GSVG) or the Eastern Group, where the marshy regions of Pomerania were expected, but Khrushchev's doctrine—"tanks are obsolete, the navy and missiles are more important"—took precedence. The prototypes were mothballed after testing: No. 1 and No. 2 in the Kubinka hangars for storage (No. 1 was restored in the 1970s for static display, No. 2 with the dismantling of the chassis), No. 3 was restored after repairs (sea trials until 1965), and No. 4 was dismantled for components for other projects. The concepts of Object 279 (autoloader, sloped armor, low pressure) were integrated into the T-64 (the first production vehicle with an autoloader, 1966) and T-72 (improved cross-country ability), as well as into the Arctic modifications of the T-80. In a hypothetical nuclear war scenario of the 1960s, Object 279 could have become an "untouchable" breacher, withstanding a close-in blast (up to 1 kt at 500 m).

Meaning and Legacy

Object 279 represents the pinnacle of Soviet heavy tank design in the 1950s, symbolizing the courage and technical genius of LKZ engineers during the era of nuclear parity and the arms race. Born in the shadow of Khrushchev's "thaw," this project embodied ambitious ideas: a four-track chassis as a response to the lessons of the Finnish War (snow and swamps) and the Korean hills; a teardrop-shaped hull as a precursor to the T-64's composite armor; and the 130mm M-65 as a prototype for the 152mm 2A83 in the Armata. Its characteristics outpaced those of its Western counterparts: compared to the American M103 (65 tons, 120mm T123, 0,95 kg/cm² pressure), Object 279 was lighter, had better maneuverability, and was better protected (versus 122mm vs. 90mm), while its autoloader reduced the crew size by 25% compared to the T-10. Four years of development and 5000+ km of testing demonstrated its effectiveness, but its cancellation reflected a shift in doctrine: from "heavy monsters" to universal OMBTs, where cost savings and mass production are more important than specialization. The legacy lives on: inclined castings in the T-72B (1985), autoloaders in the T-14 (2015), and low pressure in the Arctic T-80BVM (2020s). Without the 279, the T-64 might have been delayed, and Russian export tanks might have been inferior in protection.

Historically and culturally, Object 279 is an icon of the "lost future": rare 1960s photos from the GBTU archives, Kotin's memoirs ("We Built for the Apocalypse"), and test reports emphasize its role in the "tank renaissance." Three examples have been preserved: No. 1 at the Central Museum of Armored Vehicles in Kubinka (with a working chassis, open for viewing), and Nos. 2 and 3 at Patriot Park (Moscow Region; since 2015, Cold War exhibits). The project is popular among enthusiasts: it features in the video games "World of Tanks" (premium Tier X, 500 mm of penetration, unique mobility) and "War Thunder" (realistic tests), the documentaries "Tanks of the USSR: Forgotten Masterpieces" (Zvezda channel, 2018), and 1:35 models by Trumpeter. The LKZ archives and publications in "Modelist-Konstruktor" (2005–2010) preserve the blueprints, emphasizing its value to modern engineering. Compared to the German E-75 (concept 1945, 75 tons, 88 mm) or the French AMX-50 (1950s, 60 tons, 120 mm), the Object 279 was more futuristic, but a victim of politics.