MK17 was 24 feet 8 inches long, 61.4 inches in diameter, and weighed
between 41,400 and 42,000 lbs.; much of this was casing weight. The MK17
bomb was only four feet shorter than a POLARIS A-1 SLBM, but weighed
half again as much as an A-1.
In addition, the requirement for cumbersome, specialized, and
expensive handling equipment doomed weapons such as the MK17 to short
These bombs could only be moved with straddle loaders or large
cranes, and were not compatible with more standardized Air Force weapons
handling equipment. They also could not be carried easily by the B-47 or
The bomb casing was made of 3 1/2" thick aluminum with a lead and
plastic liner to withstand internal explosive forces for as long as
possible and to generate compressive plasma for the secondary. MK17
yield was on the order of 15 to 20 megatons, one of the most powerful
nuclear weapons ever built by the U.S.
The bomb could be carried effectively only by the B-36 aircraft;
when the weapon was dropped, the delivery airplane usually leaped
upwards several hundred feet due to the enormous weight loss.
As an example
of the handling difficulties associated with the MK17, in early 1955 a
MK17 Mod1 training weapon was assembled at Manzano for carriage by a
B-36 to Bossier Base, Louisiana because the latter site had no railhead
capable of unloading the MK17 weapon case.
A "Broken Arrow" nuclear weapons
accident involving a MK17 occurred on May 22, 1957 when a B-36 crewman
inadvertently leaned against a release mechanism that dropped an unarmed
MK17 (the "nuclear capsule" for the primary was not installed)
through closed bomb bay doors and on to the desert in New Mexico near
Kirtland Air Force Base. The HE in the bomb exploded on impact, killing
an unfortunate cow and digging a crater 12 feet deep and 25 feet in
diameter. Everyone on the
plane knew when the bomb fell: the B-36 jumped up a thousand feet.
The MK17s were
retired from the stockpile between November 1956 and August 1957. It was
withdrawn in favor of the MK 36 bomb, which was significantly smaller
and lighter and featured a lower yield.
A shift in U.S. targeting strategy from cities to military
targets, along with a significant increase in the number of
nuclear-capable SAC bombers, allowed the production and stockpiling of
large numbers of relatively-low yield bombs in the place of a small
number of high-yield bombs." *
Swords of Armageddon, Volume VI, Hansen