The Myasishchev M-4 Molot (Russian: Молот (Hammer), USAF/DoD reporting name "Type 37", ASCC reporting name Bison) was a four-engined strategic bomber designed by Vladimir Mikhailovich Myasishchev and manufactured by the Soviet Union in the 1950s to provide a Long Range Aviation bomber capable of attacking targets in North America. The aircraft fell well short of its intended range and was not fully capable of attacking the most valuable targets in the United States. As this became clear, production was shut down. In spite of the failure to produce a capable strategic design and the resulting small numbers, the M-4 nevertheless sparked fears of a "bomber gap" when 18 of the aircraft were flown in a public demonstration on May Day in 1954. The US responded by building hundreds of Boeing B-47s and B-52s to counter this perceived threat. The design was updated with more efficient engines, inflight refuelling (IFR) support and the removal of the glass nose for optical bombing and moving the radar to this location. With these changes, production restarted as the 3M. Even with these modifications the design was not truly effective in the nuclear bomber role, and only 125 aircraft, both M-4s and 3Ms, were produced before the production line was shut down for good in 1963. Only 19 of these served on nuclear alert. M-4s and 3Ms were primarily used as long-range maritime reconnaissance and strike aircraft and other supporting roles. Most were converted in the 1970s and 80s to tanker aircraft, especially as the Tupolev Tu-22M took over the maritime missions. The tanker conversions remained in service until 1994. Most surviving examples were broken up as part of post-Cold War arms limitations agreements. The M-4 was the first four-engine jet bomber deployed operationally by the Soviet Union. The M-4 was made mostly of aircraft aluminum alloys with some steel and magnesium components. It had wings swept at 35-degrees and powered initially by four Mikulin AM-3A engines with a maximum thrust of 85.8 kN (8,750 kgp; 19,290 lbf), but later upgraded to RD-3M-500 turbojets with a maximum thrust of 93.2 kN (9,500 kgp; 20,940 lbf). There were 18 bladder fuel tanks in the fuselage and wings, providing a total fuel capacity of 123,600 liters (32,610 US gallons); this gave the aircraft a range of 9,500 km (5,900 mi), although this fell short of the 12,000 km (7,500 mi) range initially specified. It had a payload of 24 tonnes (26.4 tons) in various configurations. Defensive armament consisted of six AM-23 23 mm cannons with a rate of fire of 1,250 rpm each in a manned twin tail turret with 400 rounds per gun and two twin remote controlled turrets in the top and bottom fuselage with 300 rounds per gun each. The aircraft had a crew of eight: a navigator/bombardier in the nose; pilot and copilot in the cockpit; radar operator/navigator, flight engineer/gunner, radio operator/gunner, and dorsal turret gunner in a compartment behind the cockpit; and a tail gunner. The M-4 was first displayed to the public in Red Square, on May Day, 1954. The aircraft was a surprise to the United States, which had not known that the Soviets had built a jet bomber. However, it soon became clear that the bomber had an insufficient range to attack the United States and still return to the Soviet Union. Only a few of the original production M-4s were actually put into service. To remedy this problem, the Myasishchev design bureau introduced the 3M, known to the West as the 'Bison-B', which was considerably more powerful than the previous version. This new model first flew in 1955. Among other things, two of the five original gun barbettes were removed to lighten the aircraft. For more details of design, operational history and variants, click here.