The Tupolev Tu-85 (; USAF/DoD reporting name: "Type 31", NATO reporting name: Barge) was a Soviet prototype strategic bomber based on the Tu-4, an unlicensed, reverse engineered copy of the Boeing B-29 Superfortress. It was the ultimate development of the B-29 family, being over 50% heavier than its progenitor and had nearly double the range. Only two prototypes were built before the program was cancelled in favor of the turboprop powered Tupolev Tu-95 bomber which could cover the same range at a far higher speed.
Development
Neither the Tu-4 nor the Tu-80 were true intercontinental strategic bombers as they both lacked the range to attack the United States from bases in the Soviet Union and return. The Tu-85 was designed to achieve the necessary range by use of more powerful and fuel-efficient engines, a redesigned wing to increase the lift/drag ratio and the addition of more fuel. A large number of engines were considered before settling on the Shvetsov ASh-2K, essentially two air-cooled ASh-82 radial engines paired together and the liquid-cooled Dobrynin VD-4K six-bank inline engine, similar in configuration to the unsuccessful German Junkers Jumo 222. Both proposed powerplants were given turbochargers and power-recovery turbines to turn them into turbo-compound engines. The Shvetsov design was preferred, but was not yet mature enough for use, and the VD-4K was selected. A lot of effort was put into refining the design of the wing in collaboration with TsAGI. It had an aspect ratio of 11.745 and a taper of 2.93 for optimum lift at high altitudes. The Tu-85 carried of fuel in 48 flexible tanks.
Much of the armament and equipment was derived from those of the late-model Tu-4, including the four remotely-controlled dorsal and ventral gun turrets and the tail turret, each with two Nudelman-Rikhter NR-23 cannon. But the Tu-85's tail turret had an Argon range-only radar and each of the two bomb bays was enlarged to hold a FAB-9000 bomb. It first flew on 9 January 1951 and the manufacturer's tests lasted until October. On 12 September the first prototype flew with a bombload of which it dropped en route,