Mk28.jpg (42875 bytes)   MK28 Building Block.jpg (49004 bytes) * See note below
(click to enlarge - opens in new window)

Width:  ~ 21 inches
Length:   ~ 100 inches
Weight:  ~ 1,800 pounds
Yield:  Variable 70 KT to 1.1 MT
Appr. 4,500 produced      Last retired in 1991

     "The MK 28 was one of the longest-serving and most common thermonuclear weapons in the U.S. arsenal until it was eventually replaced by B61 and B83 bombs. It was the first U.S. nuclear warhead to be designated as a complete weapon system.  MK 28 warheads, fuses, and shape components could be assembled into five different "drop shapes" resulting in a range of sizes, configurations, and yields called the "Building Block" principle.  The W-28 warhead was used in the USAF HOUND DOG air-to-surface and MACE surface-to-surface missiles.
     The MK 28 family was for many years the "standard arm" of USAF SAC and TAC bombers and fighter-bombers. Even as late as 1982, 24 years after its first stockpiling, the MK 28 was still deployed in three versions: two tactical bombs and a strategic laydown bomb.  Approximately 4,500 MK 28 bombs (in all variants) were produced between August 1958 and May 1966. Among U.S. nuclear warheads, this total was surpassed only by the W-68 POSEIDON SLBM warhead.  At the time of its tests, the TX-28 was the smallest thermonuclear system yet fired, and had the highest yield-to-weight ratio of any U.S. thermonuclear bomb." *

* Swords of Armageddon, Volume VI, Hansen