After the creation of the atomic bomb, the strategic bomber was the only means of its delivery. Since 1943, the B-29 was in service with the American Air Force. In the USSR, for this purpose in 1945, the Tupolev Design Bureau developed the aircraft "64" - the first post-war four-engine bomber. However, the solution of issues on equipping this aircraft with modern navigation and radio equipment, weapons systems and the like was delayed. This was due to the fact that the Second World War did not allow for broad promising developments. To resolve the situation in the shortest possible time, a government decree was issued instead of the 64 aircraft to develop the B-4, taking as a basis the American B-29 aircraft available in the Soviet Union, equipped with modern equipment.
In the USSR, American bombers appeared at the end of the war. US Air Force pilots began to carry out massive raids on Japan and the territory of China occupied by the Japanese on the Superfortress B-29. If enemy air defenses damaged the aircraft, its crew was allowed to land at the nearest airfield in the USSR. Thus, in the Far East there were 4 of the newest American B-29 bombers for that time.
Stalin knew about these planes and that they were equipped with the most modern equipment. He also understood that the development of domestic equipment for Myasishchev's "64" and "VM" dozens of research institutes and design bureaus would take a lot of time, which the country simply does not have. In addition, Vladimir Mikhailovich Myasishchev himself suggested making a copy of the American bomber. Therefore, Stalin made, probably, the only correct decision in this situation: the Soviet industry was instructed in the shortest possible time to establish the production of copies of the American aircraft and all its systems. It was Tupolev who was invited to head this grandiose project.
The assignment for the development of the aircraft, designated B-4, was included in the experimental aircraft construction plan of the Minaviaprom for 1946, but its main characteristics were approved only on February 26, 1946 by a corresponding government decree. According to these characteristics, the normal take-off weight was determined at 54,500 kg, and the overload weight should not have exceeded 61,250 kg. Near the ground, the speed was supposed to be at least 470 km / h, at an altitude of 10, 5 km - 560 km / h.
A group of specialists familiar with similar technology was sent to the Far East to study American B-29s. The group was headed by Reidel, who was previously engaged in the ferrying of aircraft. Tests in the Far East continued until 1945-21-06, after which three aircraft were ferried to the Izmailovsky airfield in Moscow. One of them was subsequently completely disassembled for a comprehensive study, and two were used for comparison as standards. The fourth aircraft with tail number 42-6256 and bearing the name "Ramp Tremp" (a tramp was depicted on the fuselage), at the request of Marshal Golovanov, commander of long-range aviation, was transferred to the Balbasovo airfield near Orsha. This aircraft became part of the 890th Aviation Regiment.
Each separate unit from the disassembled aircraft was processed by its own team of technologists and designers. The part or unit was weighed, measured, described and photographed. Every part of the American bomber was subjected to spectral analysis to determine the material used. However, it was definitely impossible to repeat the B-29.
During the copying of the airframe design, the problems began with the skin. It turned out that the process of converting the inch size to the metric system is rather complicated. The thickness of the plating sheets of the American aircraft was equal to 1/16 of an inch, which, when converted to the metric system, was 1.5875 mm. None of the domestic enterprises undertook to roll sheets of this thickness - there were no rolls, calibers, and measuring tools. At first, we decided to round off. However, if they rounded up to 1, 6 mm, aerodynamics began to protest: the mass increased, and they could not guarantee the required speed, range and height. When rounded down (up to 1, 5 mm), strengths began to object, since strength was not guaranteed. The question was solved by engineering. As a result, sheets of various thicknesses (from 0.8 to 1.8 mm) were used for the fuselage. The thickness was chosen depending on the strength requirements. A similar situation has developed with wires. When the cross-section of the wires was transferred to a metric, a scale with a range from 0.88 to 41.0 mm2 was obtained. An attempt to use the nearest domestic cross-sections ended in failure. If rounded to "plus", the mass of the power grid increased by 8-10%, and when rounded to "minus", the voltage drop rate did not fit. After a lengthy debate, the cablemen decided to copy the American cross-sections.
The engines were easier. This is due to the fact that even before the war, the American company Wright and the motor-building design bureau of D. Shvetsov signed a licensing agreement. For example, the M-71 - the engine for the Polikarpov I-185 - was close to the "Duplex Cyclone" installed on the B-29 Wright R-3350. Units in which the Soviet industry lagged far behind were put into production without change - carburetors, General Electric turbochargers and their control system, heat-resistant multi-turn bearings, magneto.
For the Soviet bomber, radios were used different from those installed on the B-29. On the "Americans" there were shortwave stations of an outdated design, and on Lendleigh bombers of later releases, the latest ultrashortwave stations were installed. It was decided to put them on our plane.
The doors of the Tu-4 bomb bay are open (board number 223402), the shooting date is unknown (photo from the archive of Valery Savelyev, The greatest difficulty in copying was caused by the computers that were part of the remote control system for defensive small arms. The system combined 5 turrets with 2 guns each. Each of the five shooters from their seat could control any combination of these settings. The distance between the bow and stern arrows was about 30 m, the fire was fired at a distance of 300-400 meters. Thus, the distance between the gun and the shooter could be about 10 percent of the distance between the gun and the target. These conditions were forced to take into account the parallax of the target when shooting. Computing machines introduced an amendment to it with lightning speed, when one of the shooters took control of the fire from several turrets. The rifle sights were collimator.
The radar bomb sight consisted of more than 15 blocks, a platform with a modulator and antenna released from the fuselage, indicators for the operator and navigator. The aircraft was equipped with an autopilot, which was coupled with an optical sight, radio and magnetic compasses, and a coordinate counter.
Tu-4 (this designation was assigned to the B-4 in the fall of 1947), created on the type of the American B-29, was transferred to mass production at the end of 1946. Due to the novelty of the on-board equipment and materials used, the design solution, the aircraft made a real revolution in the technologies of the aviation industry and in related industries.
In 1947, the first three Tu-4 strategic bombers were tested by test pilots Rybko, Vasilchenko and Gallay. In January of the next year, two Tu-4s (commanders Ponomarenko and Marunov) went on long-distance flights, having covered 5 thousand.km without landing from Moscow to Turkestan. Tu-4 in the vicinity of Turkestan dropped 2 tons of bombs.
The technique of piloting the Tu-4 turned out to be quite simple and accessible to intermediate-skilled pilots who had good training in blind and night flights.
Scheme Tu-4 - a cantilever all-metal monoplane with a mid-wing and canvas sheathing of rudders and ailerons. The landing gear of the aircraft with a nose wheel and retractable tail support was equipped with hydraulic brakes. Structurally, the fuselage was divided into five detachable parts: pressurized cabin, central fuselage part, middle pressurized cabin, aft fuselage part and aft pressurized cabin. A sealed manhole with a diameter of 710 millimeters was used to connect the front cockpit and the middle one. In the central part there were two bomb compartments with opening doors.
Manned prototype K at the airfield and under the wing of the Tu-4 carrier (Kazmin V., "Comet" is almost invisible. // Wings of the Motherland. No. 6/1991, The power plant of the aircraft is four air-cooled ASh-73TK piston engines. The engines were developed at OKB-19 by A. D. Shvetsov. For flight at high altitudes, each engine was equipped with two TK-19 turbochargers. Engines with a takeoff power of 2,400 hp. each provided a Tu-4 bomber with a speed of 420 km / h at an altitude of 10,000 m - 558 km / h, a ceiling of 11,200 m. The flight range with a bomb load of 2 tons was 5100 km. Normal take-off weight - 47,500 kg, the maximum with a bomb load of 8 tons could reach 66,000 kg. The engines were equipped with four-blade propellers with variable pitch in flight.
Wing - two-spar trapezoidal, high aspect ratio. It housed 22 soft fuel tanks with a total volume of 20180 liters. If it was necessary to perform a long flight with a lower bomb load, three additional tanks with a total fuel volume of 5300 kg were installed in the front bomb bay. each engine used its own fuel and oil systems.
Anti-icing devices - rubber pneumatic protectors installed along the leading edge of the stabilizer, wing and keel with a fork. The propellers were protected by pouring the leading edges of the blades with alcohol and glycerin. The high-altitude equipment included devices for supplying the cabins with air, maintaining pressure in them, and heating. The air was supplied from the turbochargers of medium-sized engines. Up to an altitude of 7 km, the pressure in the cabins was automatically maintained, which corresponded to an altitude of 2.5 km.
The defensive armament consisted of 10 B-20E or NS-23 cannons housed in 5 remote-controlled towers. At the same time, the control of all firing installations could be carried out by one person from any place. The stock of bombs is 6 tons. Bombers carrying nuclear weapons (Tu-4A) could take on board one atomic bomb. The machines were equipped with biological protection.
On the Tu-4, for the first time in the domestic aircraft industry, all elements of the equipment were combined into systems. The onboard equipment, in particular automation, has significantly increased the combat effectiveness of the aircraft. An onboard locator and autopilot allowed the crew to detect and engage targets from behind the clouds at night. With the help of automation, the most advantageous operation of the engines was maintained, which provided an increased flight range. Dozens of electric motors helped the crew to control the aircraft's moving elements; rudders, flaps and landing gear. For the first time in bomber aviation, a navigator was fitted with a Cobalt radar bomb sight, which was completely copied from the American model. The sight made it possible at any time of the day and under various meteorological conditions to detect large industrial centers (such as Moscow) at a distance of 90 kilometers. Smaller cities with developed industry - up to 60 km, bridges and railway stations - 30-45 km. Lakes and large rivers (for example, the Volga) were clearly observed from a distance of up to 45 km.
KS-1 cruise missiles for Tu-4K (https://crimso.msk.ru)
The introduction of the Tu-4 into production proceeded without delay and rather energetically. 1947-19-05 took place the first flight of the first production aircraft (crew commander Rybko N. S.), then the second (Gallay M. L.) and the third (Vasilchenko A. G.). On November 11, 1946, even before the first flights, the Berlin newspaper Der Kurier announced the beginning of production in the Soviet Union of copies of the American B-29. Nobody believed in this in the West. It was believed that the USSR was not in a position to establish the production of such equipment. But all doubts were dispelled during the air parade on 1947-03-08 in honor of Aviation Day. Then the first three production vehicles and the passenger Tu-70 were demonstrated. Comprehensive testing of 20 copies of the first series lasted about two years, the defects found were eliminated and the further release went confidently, without any complications. Flight crew training was supervised by test pilot V. P. Marunov, who mastered B-29 flights during his service in the Far East. Serial production of Tu-4 bombers was established at Soviet factories, and by the end of 1949 there were more than 300 aircraft in long-range aviation. In total, about 1200 aircraft were produced during production.
In the USSR, Tu-4 aircraft became the last serial heavy bombers equipped with piston engines. Until the mid-1950s, they were the backbone of the Soviet Union's strategic aviation. They were replaced by new generation aircraft equipped with powerful gas turbine engines.
Several modifications of the Tu-4 were produced:
Tu-70 is a passenger version of a strategic bomber, a low-wing aircraft, which differed only in a slightly increased diameter and length of the fuselage. It had the same power plant. Design and construction proceeded in parallel with the serial construction of the first Tu-4.
Tu-75 is a military transport version of the Tu-70 aircraft. It differed from it by a large cargo hatch, made on the lower surface of the rear fuselage. The hatch cover served as a ladder for rolling vehicles and cargo into the fuselage. In this transport version, rifle installations were re-introduced - aft, upper front and lower rear. Purpose - transportation of cargo up to 10,000 kg or 120 paratroopers with weapons. The crew is six people.
Tu-80 is a direct development of Tu-4. Significant changes were made to the outline of the fuselage - instead of "domed" glazing, a visor was installed in the nose. Improved aerodynamics due to the fact that the side blisters of the aiming stations were semi-filled into the fuselage. The aircraft is equipped with new forced ASh-73TKFN engines with fuel injection into the cylinders and turbochargers. It was built in a single copy.
Tu-4R is a strategic reconnaissance aircraft. On this aircraft, to increase the flight range, an additional gas tank was mounted in the front bomb bay, and photographic equipment was placed in the rear bomb bay.
Tu-4 LL is a flying laboratory used as a research aircraft. It tested new systems of radio and radar equipment, tested the air refueling system, tested turboprop and jet engines.
Tu-4T - airborne transport version, produced in 1954 in a single copy. Seats for 28 people were installed in the bomb bays. For military equipment, streamlined containers were installed, as well as a mounting system that allowed them to be suspended under the fuselage or wing. The containers were detached and dropped by parachutes. Tu-4 lifted two containers with a total weight of 10 tons.
Tu-4D is a landing variant developed by OKB-30 after Tu-4T. During the conversion, they removed the middle pressurized cabin, weapons (only the aft installation was left) and a cabin for 41 paratroopers appeared in the bomb bay instead. There were amphibious cargo suspension units under the wing.
Tu-4KS is a carrier aircraft for the Kometa missile system. The "Kometa" consisted of: a KS rocket ("comet-plane"), its guidance equipment, placed on the plane, as well as ground support facilities. On the Tu-4KS aircraft, two spacecraft were suspended under the wing.
Tu-4 with PRS-1 - serial Tu-4, equipped with the "Argon" radar sighting station installed in the stern installation. Released in a single copy.
"94" - Tu-4 with turboprop engines of the TV-2F type.
Tu-4 tanker.
The first strategic bomber Tu-4 was received by the 185th Guards Aviation Regiment of the 13th Air Division, located in Poltava. The personnel trained in Kazan, on the basis of the 890th long-range bomber regiment transferred there.
Tu-4 is the first Soviet nuclear weapons carrier. By decision of the Council of Ministers of the USSR No. 3200-1513 of 29.08.1951, the Ministry of War began to form a bomber regiment armed with atomic bombs. The regiment received the code name "Training unit number 8". It included 22 combat carrier aircraft. The regiment was manned with personnel from the Forty-fifth Heavy Bomber Aviation Division. The regiment commander - Colonel V. A.
Tu-4 factory # 2805103 at the Russian Air Force Museum in Monino, 20.09.2008 (photo - Vitaly Kuzmin, During the Hungarian events in 1956, the Tu-4 compound flew to the bombing of Budapest. To misinform NATO countries, the flight was carried out not along the shortest route, but through the territory of Romania. At the last moment, it was interrupted by an order from the command.
Tu-4 production was discontinued in 1952. 25 of the produced aircraft were transferred to the PRC. Piston motors were replaced by AI-20M turboprop motors in the mid-1970s. In 1971, one Chinese Tu-4 was converted into a KJ-1 ("Air Police-1") long-range radar detection aircraft, and the rest became carriers of the WuZhen-5 unmanned aerial vehicles (a copy of the American AQM-34 Firebee).
Aircraft performance characteristics:
Developer - Tupolev Design Bureau;
First flight - 1947;
Serial production start - 1947;
Aircraft length - 30, 18 m;
Aircraft height - 8, 95 m;
Wingspan - 43.05 m;
Wing area - 161.7 m2;
Chassis track - 8, 67 m;
Engines - 4 piston engines ASh-73TK;
Engine power - 1770 kW (2400 hp);
Weight:
- empty aircraft - 32270 kg;
- normal takeoff 47500 kg;
- maximum - 66,000 kg;
Maximum flight speed - 558 km / h;
Maximum flight range - 6200 km;
Mileage - 1070 m;
Takeoff run - 960 m;
Service ceiling - 11200 m;
Crew - 11 people
Armament:
- initially 10 x 12, 7 mm UB machine guns, then 10 x 20 mm B-20E cannons, later 23 mm NS-23;
- bomb load - from 6000 to 8000 kg (from 6 to 8 FAB-1000).
Prepared based on materials:
