Amodel – NA72006 – RDS-6s/RDS-27 (Soviet hydrogen bomb)

Description:

The RDS-6s—also known by the Western codename Joe-4—was the first Soviet thermonuclear weapon, tested on August 12, 1953. However, it was not a “true” hydrogen bomb by later standards, but rather a boosted fission device, sometimes referred to as a “layer-cake” design. It used a combination of fission and fusion reactions, with a core of plutonium surrounded by layers of lithium-6 deuteride and uranium-238. The fusion reaction boosted the efficiency and yield of the fission process but did not rely on a full multi-stage thermonuclear reaction like the Teller-Ulam design developed later by both the U.S. and USSR.

The RDS-6s had a yield of around 400 kilotons, significantly larger than previous Soviet fission bombs, and was a major milestone in Soviet nuclear weapons development. The test demonstrated that the USSR was rapidly closing the gap with the United States in thermonuclear technology. Importantly, it could be delivered by existing aircraft and did not require the massive infrastructure or delivery systems that true H-bombs would later need.

The RDS-27, by contrast, was a refined fission bomb, not a thermonuclear weapon. It was developed in parallel as a more practical, weaponized version of earlier designs, possibly incorporating some of the technological lessons from RDS-6s but without using fusion. Its purpose was to serve as a more deployable, reliable strategic weapon while work continued on more advanced designs.

In summary, the RDS-6s marked the USSR’s entry into the thermonuclear club—at least symbolically—while the RDS-27 represented a pragmatic evolution of Soviet fission bomb technology. Together, they illustrate the transitional phase in Soviet nuclear weapons development in the early 1950s, as the country moved from basic atomic bombs to truly thermonuclear weapons.

Kit include PE (photo-etched) parts and plastic parts for the bomb and transport cart.