OVERVIEW: The B57 is a tactical, multipurpose, air-delivered nuclear bomb designed for use against surface targets, submarines, and other naval or land threats. It is an unguided, free-fall bomb with selectable yield options ranging from sub-kiloton to 20 kilotons.

DETAILS: The B57 was developed by the United States in the late 1950s and entered service in 1963, primarily for naval strike and anti-submarine roles. It features a slender cylindrical body optimized for low-level delivery and compatibility with carrier-based aircraft. The B57 designation identifies it as a bomb (“B”) with model number 57, and it carried the W57 fission warhead with variable yield. The bomb included laydown delivery capability and was designed for detonation by contact or timed delay fuze. It served a dual-purpose role in both strategic deterrence and tactical naval missions, particularly in Cold War maritime environments.

The Mod 0 through Mod 5 variants introduced improvements such as variable yield settings, enhanced safety interlocks, and delivery options for multiple platforms. Later mods supported low-altitude laydown delivery with reinforced casings and environmental sensing devices. Mod 3 and Mod 5 versions were the most widely deployed, offering better reliability and compatibility with newer aircraft. The bomb remained in service until the early 1990s and was replaced by more modern precision nuclear systems.

The B57 was externally mounted on pylons or carried internally depending on the aircraft type. Prior to release, crews selected fuze mode and yield settings using aircraft-mounted controls to match specific mission profiles.

NOTE:
IOC: 1963
Operators: United States
Platforms: A-4 Skyhawk, A-6 Intruder, A-7 Corsair II, F-4 Phantom II, S-3 Viking, P-3 Orion
Conflict used in: Not used in combat

SOURCE:
U.S. Department of Energy: https://www.energy.gov ; U.S. Navy Nuclear Weapons Deployment Reports ; Federation of American Scientists (FAS): https://fas.org ; National Security Archive: https://nsarchive.gwu.edu ; U.S. Air Force Armament Museum ; Jane’s Weapons: Air-Launched