Object 277

Historical overview

Object 277 was a late Soviet experimental heavy tank designed to replace or surpass the T-10 rather than to create a fundamentally new main battle tank. The vehicle is described as a Soviet prototype/cancelled heavy-tank family, gives the development span as 1956–1958, and records two prototypes as the commonly cited figure, while marking the record less certain because the vehicle remained an experimental project. Sources

The tank mattered because it concentrated several late-1950s Soviet heavy-tank ambitions in one design: a 130 mm M-65 gun, a two-plane stabilizer, stereoscopic rangefinding, assisted ammunition handling, heavy cast armor, NBC-related protection, and a powerpack intended to keep a 55-ton vehicle at medium-tank-like road speeds. Russian secondary references agree on the broad design picture, although they diverge on several exact specifications. [BK96; K96-277] Sources

Its historical significance is mostly negative and transitional. Object 277 did not fight and did not become a series-production tank. Its importance lies in showing what the Soviet heavy tank might have become immediately before the heavy-tank category was effectively abandoned in favor of lighter, missile-capable, and eventually MBT-centered designs. Sewell’s U.S. Army ARMOR article links Object 277 to Khrushchev-era pressure against heavy-tank design work, while Russian sources emphasize the technical competition among Object 277, Object 279, and Object 770. [ARMOR98; BK96; K96-277; K96-279; K96-770] Sources

The most important related vehicle is Object 278, a gas-turbine derivative normally treated as an Object 277-family offshoot. Object 279 and Object 770 are not variants of Object 277, but they belong in any serious discussion because they were parallel late-heavy-tank competitors under similar tactical requirements. Some secondary accounts state that Object 277 failed to show enough advantage over the Chelyabinsk design to justify continued work. [K96-278; K96-279; K96-770; WG-277] Sources

Object 277 was technically formidable but strategically late. It was too immature, too heavy, and too tied to a doctrinal category that Soviet leadership and tank design were already leaving behind. It deserves attention not because it changed the battlefield, but because it captures the end of the Soviet heavy-tank design tradition in a single, surviving museum artifact. [PARK; BK96; K96-277; ARMOR98] Sources

The Soviet heavy-tank tradition after the Second World War had two overlapping purposes: battlefield breakthrough against fortified or heavily armored opposition, and operational prestige as the armored arm’s hardest-hitting vehicle. The IS-series experience, the IS-7 experiments, and the T-10 production line formed the design memory behind Object 277. By the mid-1950s, however, that tradition was under pressure from more powerful antitank weapons, tactical nuclear assumptions, weight limits, and the emergence of tanks that tried to combine heavy-tank firepower with medium-tank mobility. [BK96; ARMOR98] Sources

Russian heavy-tank accounts place the immediate start point around 1956, when the Soviet Army’s armored authorities developed new tactical-technical requirements for a heavy tank intended to replace the T-10. The same account describes the competition as involving three design collectives in Leningrad and Chelyabinsk. This puts Object 277 in a procurement contest rather than as a one-off sketch. Sources

The doctrinal problem was difficult. A successor to the T-10 had to carry a gun able to overmatch contemporary heavy armor, preserve enough armor to justify the “heavy” category, and still remain mobile enough for the increasingly fluid, nuclear-age battlefield. Object 277 attempted to answer by using a 130 mm gun and high-output powerpack while staying near 55 tonnes—heavy, but not in the weight class of abandoned super-heavy concepts. [BK96; K96-277] Sources

Politically and institutionally, the design emerged in the Khrushchev period, when missiles received intense attention and heavy armored vehicles were increasingly vulnerable to criticism as expensive, specialized, and backward-looking. Sewell’s ARMOR account presents Khrushchev as pressing the tank bureaus toward missile-firing designs and links Object 277 to the termination of heavy-tank design work. That account is described as an interpretive secondary source, but it matches the broader trend: Object 277 belonged to a category whose political support was collapsing. Sources

Development and variants

This is appropriate: Object 277 is a clear tank, but it sits on a boundary between full family entry, single prototype, and programmatic footnote. Sources

Related vehicles often confused with Object 277 include Object 278, which retained the general Object 277 configuration but used a gas-turbine engine; Object 279, the four-track special-purpose heavy tank; Object 770, the Chelyabinsk heavy tank competitor; Object 272/734 T-10M variants; and Object 150/IT-1, a missile tank shown in the same late-1950s/early-1960s doctrinal environment. [K96-278; K96-279; K96-770; ARMOR98] Sources

Accounts differ over prototype numbers, trial dates, ammunition stowage, engine ratings, the construction of Object 278, and reasons for cancellation. Their compressed chronologies do not resolve every disagreement. [BK96; K96-277; K96-278; WG-277] Sources

The standard Russian secondary narrative is that the new heavy-tank requirements appeared about 1956 and that Object 277 was designed in 1957 by the chief-designer bureau of the Leningrad Kirov Plant under Zh. Ya. Kotin. The design reportedly reused selected solutions from IS-7 and T-10 practice, which is consistent with the published account’s “T-10/IS lineage” note and with the vehicle’s conventional layout. [BK96; K96-277] Sources

The development timeline is source-sensitive. Published accounts describe 1956–1958 as the family development/start span and the prototype tab gives 1957. Baryatinsky, Kolomiets, and Koshchavtsev state that two Object 277 examples were built in 1958 and that trials were soon stopped. Wargaming’s historical note, which is useful but lower in authority, says two prototypes underwent trials from 1959 through 1960 and adds that a hull and turret were made for ballistic testing. These details remain unconfirmed in the cited evidence. [BK96; WG-277] Sources

Object 277 was not alone. Object 279 represented a more radical Leningrad answer with a distinctive four-track running gear, while Object 770 represented a Chelyabinsk heavy-tank response. The Object 278 gas-turbine derivative seems to have been developed alongside the same LKZ line, but its status is disputed: Karpenko lists it as built in 1957, while the Baryatinsky/Kolomiets/Koshchavtsev prose describes it as projected but not built. [BK96; K96-278; K96-279; K96-770] Sources

The cancellation story has two layers. Technically, the program did not demonstrate an irresistible advantage over its rivals, and at least one secondary note says the vehicle’s systems and components were insufficiently mature. Politically, Khrushchev-era skepticism toward heavy tanks and enthusiasm for missiles cut against any heavy-tank successor. The evidence indicates that Object 277 failed in a hostile procurement environment: it was not only a prototype with unresolved details, but a prototype for a category Soviet leadership no longer wanted to expand. [ARMOR98; WG-277; BK96] Sources

Design and performance

Object 277 used a classic tank layout: driver and controls forward, fighting compartment in the center under a large cast turret, powerpack at the rear, and rear drive sprockets. This was evolutionary rather than radical, especially compared with Object 279. [BK96; K96-277] Sources

The hull was welded from bent armor plates with variable thickness and varying angles. Baryatinsky/Kolomiets/Koshchavtsev describe a one-piece cast frontal section and a trough-shaped bottom; Karpenko likewise notes bent side plates, cast front, and trough bottom. These features suggest an attempt to blend proven heavy-tank fabrication methods with improved ballistic shaping. [BK96; K96-277] Sources

The turret was cast and streamlined, with a long rear bustle used for mechanized or assisted ammunition stowage. The gun opening was enclosed and did not use a conventional external mantlet, a detail that probably contributes to the “internal mantlet” wording seen in later photo captions. Turret thickness is reported as ranging from about 77 mm to 290 mm, with 290 mm commonly cited for the front. [BK96; K96-277; IMG-AW] Sources

Karpenko gives the frontal hull armor as 140–153 mm and turret front as 290 mm. The Baryatinsky/Kolomiets/Koshchavtsev account gives the turret wall range as 77–290 mm. Because both are secondary references and not original armor drawings, these figures are described as useful but not final for ballistic modeling. [BK96; K96-277] Sources

The main weapon was the 130 mm rifled M-65 gun. Russian sources emphasize the high nominal muzzle velocity of the armor-piercing projectile and the use of a barrel-purge system—compressed-air purge in one account, ejector-type language in another. The gun was the centerpiece of the design and was shared across late Soviet heavy-tank experiments. [BK96; K96-277; K96-279; K96-770] Sources

The coaxial secondary weapon was a 14.5 mm KPVT heavy machine gun. Ammunition stowage for the machine gun is disputed: one major account gives 250 rounds, while Karpenko gives 804 rounds. Accounts record both values rather than forcing a false precision. [BK96; K96-277] Sources

Main-gun ammunition capacity is the largest technical conflict in the available open sources. Baryatinsky/Kolomiets/Koshchavtsev give 26 rounds, while Karpenko gives 35. A 2024 photo of a museum placard appears to support 35 main-gun rounds but is treated only as a photo lead because the underlying exhibit-text rights and exact source chain are unclear. [BK96; K96-277; IMG-MBH] Sources

Object 277 was fitted with the Groza two-plane stabilizer and an automated fire-control or gun-control system. It used a stereoscopic rangefinder sight identified as TPD-2S or TDPS in transliterated sources. This was a major modernization over earlier heavy-tank fire-control practice. [BK96; K96-277] Sources

The sight package included the TPD-2S/TDPS stereoscopic rangefinder and night firing/observation devices, with Karpenko specifically listing TPN-1 for night sighting. These details place the tank in the same modernization wave as late T-10 and early MBT experiments. [BK96; K96-277] Sources

The diesel Object 277 used an M-850 12-cylinder V-type diesel with forced induction and ejector cooling. Power output is disputed: Karpenko lists 1,000 hp, while Baryatinsky/Kolomiets/Koshchavtsev give 1,090 hp at 1,850 rpm. The mechanical planetary transmission was an eight-speed unit integrated with the engine block; the steering and brake details differed from T-10 practice. [BK96; K96-277] Sources

The running gear had eight road wheels per side and four return rollers per side. Sources describe torsion-bar suspension, with Baryatinsky/Kolomiets/Koshchavtsev specifying bundled torsion bars and hydraulic shock absorbers on selected stations. The arrangement was conventional compared with Object 279’s four-track system. [BK96; K96-277; K96-279] Sources

Karpenko lists 55 km/h maximum speed, 300 km range, 0.75 kg/cm² ground pressure, a 35-degree climb, and a 1.2 m fording depth for Object 277. These figures give the tank impressive paper mobility for a 55-ton heavy tank, but they are prototype data and does not demonstrate proven operational performance. Sources

Crew is consistently given as four. The semi-automatic cassette loading mechanism indicates that the loader remained part of the crew but received mechanical assistance for handling large 130 mm ammunition. The turret bustle ammunition arrangement probably helped manage the gun’s size but also made ammunition layout a critical design problem. [BK96; K96-277] Sources

Karpenko lists an R-113 radio. No production-service communications fit is known because Object 277 never entered service, and no reliable evidence indicates a command version or alternate communications suite. Sources

Baryatinsky/Kolomiets/Koshchavtsev list anti-nuclear protection, thermal smoke equipment, observation-device cleaning, and underwater-driving equipment. Karpenko lists BDSH smoke-screen equipment. These features fit the late-1950s requirement to operate in contaminated and high-intensity battlefield conditions. [BK96; K96-277] Sources

No operational reliability record exists. The design depended on a powerful engine, advanced transmission, assisted loading, advanced sights, and heavy cast structures. Later secondary summaries point to immature components and systems as one reason work ended, but this remains uncertain from factory or trial reports. [WG-277; BK96; K96-277] Sources

Documented or likely weaknesses include high weight, long overall length with the gun forward, an ammunition-stowage dispute that may reflect real developmental revisions, a politically vulnerable heavy-tank role, and the absence of a clear advantage over parallel designs—especially Object 770—in some secondary accounts. [WG-277; K96-770] Sources

Production, operators, and combat record

Object 277 was an LKZ prototype program. Published accounts describe the family as Soviet, prototype/cancelled, with T-10/IS lineage. Karpenko identifies SKB LKZ as developer and LKZ as manufacturer. The Baryatinsky/Kolomiets/Koshchavtsev account likewise places design in the Leningrad Kirov Plant chief-designer bureau under Kotin. [K96-277; BK96] Sources

No series production occurred. The best-supported open statement is that two prototypes are commonly cited, with separate mention in uncertain secondary material of a hull and turret made for ballistic tests. No export production, licensed production, command version, recovery variant, bridge layer, engineering version, flamethrower version, assault-gun conversion, or tank-destroyer conversion is documented for Object 277. [BK96; WG-277] Sources

Industrial constraints were typical of a late prototype: advanced casting, heavy gun integration, fire-control equipment, powerpack development, and ammunition handling all had to work together before the design could be credible. The fact that similar 130 mm, advanced-fire-control, and loading-assist ideas appeared in Object 279 and Object 770 suggests that the wider Soviet heavy-tank program was testing a common set of technologies rather than merely building a single vehicle. [K96-277; K96-279; K96-770] Sources

Object 277 had no operational service. Its only documented “operator” in a loose sense was the Soviet test and museum system: LKZ/GABTU trial context during the late 1950s and subsequent preservation at Kubinka/Park Patriot. The Patriot Park page lists “Опытный тяжелый танк (Объект 277)” in the heavy tanks and Soviet self-propelled artillery pavilion, confirming its museum-survivor status. [PARK] Sources

The cited evidence describes a Soviet project rather than operational use by multiple Warsaw Pact armies. No source used in the cited record documents export, foreign trials, training-unit issue, combat-unit issue, or captured service. [PARK] Sources

Object 277 had no combat history. It was not accepted for service, not produced in series, not exported, and not issued to Soviet or Warsaw Pact field units. Sources

A hypothetical tactical role would have resembled a late heavy gun tank: long-range antitank fire, breakthrough support, and engagement of enemy heavy armor at distances where the 130 mm M-65 and rangefinder/stabilizer package could matter. Its limitations would have been equally clear: large size, heavy weight, large ammunition, uncertain mechanical maturity, and likely maintenance complexity. [BK96; K96-277] Sources

The absence of combat is historically important. By the time Object 277 might have matured, heavy-tank combat doctrine was losing relevance. Western heavy tanks such as the British Conqueror and American M103 existed in small numbers for similar long-range antitank problems, but all major armies were moving away from the separate heavy-tank category. [TM-CONQ; TMV-M103; ARMOR98] Sources

Legacy and historical evidence

The most relevant comparison set is not a broad catalog of Cold War tanks, but the late-heavy-tank problem of 1955–1961: the T-10/T-10M as the existing heavy tank, Object 279 and Object 770 as direct Soviet competitors, and the British Conqueror and American M103 as Western heavy-gun analogues. [BK96; K96-277; K96-279; K96-770; TM-CONQ; TMV-M103] Sources

In firepower terms, Object 277 was at the upper end of late-heavy-tank thinking. In armor terms, it was heavily protected but not as radical as Object 279. In mobility terms, its paper 55 km/h speed was impressive for its weight, but unproven in operational service. In strategic value, it was weak: a tank that cannot survive procurement politics or prove decisive advantage over its competitors is unlikely to shape force structure. [K96-277; K96-279; K96-770; ARMOR98] Sources

Object 277’s legacy is mainly as an endpoint. It shows that Soviet designers could still build a highly capable heavy gun tank in the late 1950s, but it also shows that technical capability was no longer sufficient. Heavy tanks were losing to a new design logic: compact, lower, better-protected medium/MBT designs with high-velocity guns, autoloaders, stabilized fire control, and eventually gun-launched missiles. [ARMOR98; BK96; K96-277] Sources

The design’s specific technologies—large gun, stabilization, rangefinding, assisted loading, NBC-related features, and high-output powerpack—were not irrelevant. They formed part of the same technological environment that led to later Soviet tank experimentation. However, Object 277 itself did not directly become a production ancestor in the way T-64/T-72/T-80 lines did. Its influence is best understood as a testbed and historical marker, not as a direct production lineage. [K96-277; ARMOR98] Sources

The surviving museum example gives the vehicle a modern visibility disproportionate to its historical service. Park Patriot’s official exhibit page lists Object 277 in the Soviet heavy tank and self-propelled artillery pavilion, and Wikimedia Commons hosts multiple freely licensed museum photographs. This has made Object 277 familiar to armor enthusiasts despite its lack of operational history. [PARK; COMMONS-CAT; IMG-AW; IMG-UB; IMG-SUL] Sources

A common misconception is that Object 277 was an “almost adopted” super tank stopped only by one political decision. The evidence supports a more nuanced story: it was a serious prototype in a serious competition, but sources also point to immature systems, no decisive advantage over competitors, and a strategic move away from the heavy-tank category. [BK96; K96-277; WG-277; ARMOR98] Sources

The vehicle is well attested as a real Soviet prototype and surviving museum exhibit, but many detailed figures come from secondary compilations or reproduced Russian-language references rather than directly from factory drawings, trial reports, or original technical manuals. [BK96; K96-277; PARK] Sources

Photographs and image credits

Background reading and references. Each photograph has its own source and credit.

Object 277 in the Kubinka tank museum environment, broad side/front museum view. 1 October 2015. Shows exhibit context; not evidence of original trial paint or fitting.Uwe Brodrecht; CC BY-SA 2.0, Flickr review confirmed on Commons.

Object 277 in the Kubinka armored museum exhibition. 16 August 2014. Kubinka Tank Museum.Smell U Later; CC BY-SA 4.0.

Sources and further reading

Background reading and references. Each photograph has its own source and credit.

Historical overview

Development and variants

Design and performance

Production, operators, and combat record

Legacy and historical evidence

Photographs and image credits

Sources and further reading

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