Python (nuclear primary)

According to researcher Chuck Hansen, the W34 Python was a gas-boosted fission primary used in several designs of American thermonuclear weapons.

Hansen's research indicates that the

W28, W40, and W49, and as a boosted fission warhead without a thermonuclear second stage in several other weapons. These were the Mark 45 ASTOR wire-guided 19-inch (48 cm), submarine-launched heavyweight torpedo; the Mk 101 Lulu nuclear depth bomb; the Mk 105 Hotpoint

laydown bomb.

Additionally, an anglicised

nuclear land mine

for the British Army in Germany.

The W34 used the melt-cast

high explosive Octol, a variant of HMX and TNT as the material for its implosion lenses, and this relatively unsophisticated explosive that pre-dated PBX

was perhaps a reason why the British adopted this warhead, since they were attempting to deploy a thermonuclear warhead for their strategic bombers quickly, and the British were well-versed in the manufacture, storage and use of these melt-cast explosives.

Declassified British military documents also refer to a 'Low-Yield-Python' and the AIR-2 Genie air-to-air rocket being considered by the UK for their interceptors, suggesting that there was a design linkage with the W25 low-yield warhead of the Genie. There is no hard evidence as yet, but the 11 kt yield of the W34 Python would degrade to a figure comparable with the W25 without the gas-boosting.

Historical evidence indicates that these weapons shared a reliability problem, which Hansen attributes to miscalculation of the reaction cross section of

Tsetse primary

design.

Characteristics of these weapons are:

Python primary based nuclear weapons
Model	Max yield (kt)	Diameter	Length	Weight
B28	1,450	22 in (56 cm)	170 in (4.3 m)	2,300 lb (1,000 kg)
W-28	1,450	20 in (51 cm)	60 in (1.5 m)	1,725 lb (782 kg)
W-40	10	18 in (46 cm)	32 in (0.81 m)	385 lb (175 kg)
W-49	1,440	20 in (51 cm)	58 in (1.5 m)	1,610 lb (730 kg)
W-34	11	17 in (43 cm)	32 in (0.81 m)	320 lb (150 kg)
Possible family members
W25	1.7	17.4 in (44 cm)	26.6 in (0.68 m)	221 lb (100 kg)

External links

Beware the old story by Chuck Hansen, Bulletin of the Atomic Scientists, March/April 2001 pp. 52–55
Various Ministry of Defence and Ministry of Aviation declassified files lodged in the National Archives, London.
Complete List of All U.S. Nuclear Weapons
Richard Brown's sectioned b/w line drawing.
Richard Brown's sectioned colour drawing.
Richard Brown's colour exterior drawing.

See also

External links