OVERVIEW: The RN-40 is a Soviet tactical nuclear bomb, developed for strike missions using frontline aircraft.

DETAIL: Designated as 8U-64, the RN-40 was developed during the late Cold War period as an evolution of earlier tactical nuclear munitions such as the RN-28. It was designed to be air-delivered by tactical bombers and fighter-bombers, primarily the Su-24, with improved yield and aerodynamic handling characteristics. The bomb likely utilized an advanced fission or boosted-fission warhead, optimized for maximum destructive effect against fortified targets, troop concentrations, and infrastructure.

The RN-40 featured a streamlined casing for compatibility with high-speed, low-altitude delivery profiles and was fitted with a versatile fuzing system for airburst or ground impact detonation. Its greater yield (compared to earlier tactical bombs) provided expanded mission flexibility without moving into the strategic weapons class. The system reflected a doctrinal shift toward theater nuclear options within the Soviet military planning framework of the 1980s.

It remained in the inventory of the Soviet Air Force and was later inherited by Russia before being progressively retired in the post-Soviet period under arms reduction efforts. There is no public record of its operational use or testing beyond design development.

NOTE:
IOC: ~1980s
Operators: Soviet Union (retired)
Platform: Su-24, Su-17M3, MiG-27, Tu-22M
Conflicts: None (Cold War deployment posture only)

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