OVERVIEW: The RN-42 is a Soviet high-yield strategic nuclear bomb developed for delivery by long-range bombers.

DETAIL: The RN-42 was designed during the late Cold War as part of the Soviet Union’s arsenal of thermonuclear gravity bombs intended for strategic deterrence. Although detailed public specifications are scarce due to classification, the RN-42 is believed to have been a multi-megaton thermonuclear weapon developed for use with heavy bombers such as the Tu-95 and Tu-160. It likely incorporated advanced staged radiation implosion technology, offering a yield in the range of several megatons.

Its casing dimensions and aerodynamics suggest compatibility with external or semi-recessed carriage under large strategic platforms. The bomb was engineered for flexible mission profiles, including both high-altitude and low-altitude drops, and was possibly fitted with parachute-retardation systems for laydown delivery options.

The RN-42 formed part of the Soviet strategic reserve and was likely stored in hardened facilities during peacetime, assigned to long-range aviation regiments as a second-strike option. Like many Soviet-era high-yield bombs, it was progressively withdrawn from service under arms reduction treaties such as START I and II, and retired by the early 2000s.

NOTE:
IOC: ~1980s
Operators: Soviet Union (retired)
Platform: Tu-95MS, Tu-22M3, Tu-160
Conflicts: None (strategic reserve only)

SOURCE:
Federation of American Scientists (FAS) ; Russian Ministry of Defence archives ; IISS Military Balance ; SIPRI Nuclear Forces Databook ; Jane’s Nuclear, Biological and Chemical Defence
https://fas.org ; https://www.sipri.org ; https://www.iiss.org