Python primary
Encyclopedia
According to researcher Chuck Hansen
, the W34 Python was a gas-boosted fission primary used in several designs of American thermonuclear weapons.
Primary is the technical term for the fission bomb trigger of a thermonuclear or fusion bomb, which is used to compress, heat and ignite the fusion fuel in the thermonuclear secondary.
Hansen's research indicates that the W34 Python primary was used in the US B28 nuclear bomb
, 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 21 inch, submarine launched heavyweight torpedo; the Mark 101 Lulu nuclear depth bomb
; the Mark 105 Hotpoint laydown bomb.
Additionally, an anglicised W34 Python known to the British as 'Peter' was manufactured in Britain as the primary for Red Snow
, itself an anglicised W28 warhead. Peter was also proposed as a replacement for the Red Beard
warhead housed in a Red Beard carcass, and as the Violet Mist nuclear land mine for the British Army in Germany.
The W34 used the melt-cast high explosive Cyclotol, a variant of HMX
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 tritium
in fusion reactions. The weapons were not tested as extensively as some prior models due to a mid-1960s nuclear test moratorium, and the reliability problem was discovered and fixed after the moratorium ended. The flaw was apparently common with the W44 Tsetse primary
design.
Characteristics of these weapons are:
Chuck Hansen
Chuck Hansen compiled, over a period of 30 years, the world's largest private collection of documents on how America developed the atomic bomb. These documents were obtained through the U.S...
, the W34 Python was a gas-boosted fission primary used in several designs of American thermonuclear weapons.
Primary is the technical term for the fission bomb trigger of a thermonuclear or fusion bomb, which is used to compress, heat and ignite the fusion fuel in the thermonuclear secondary.
Hansen's research indicates that the W34 Python primary was used in the US B28 nuclear bomb
B28 nuclear bomb
The B28, originally Mark 28, was a thermonuclear bomb carried by U.S. tactical fighter bombers and bomber aircraft. From 1962 to 1972 under the NATO nuclear weapons sharing program, American B28s also equipped six Europe-based Canadian CF-104 squadrons known as the RCAF Nuclear Strike Force...
, W28, W40
W40
The W40 nuclear warhead was an American nuclear warhead developed in the late 1950s and which saw service from 1959 to 1972. It was a fusion boosted fission bomb type....
, and W49
W49
The W49 was an American thermonuclear warhead, used on the Thor, Atlas, Jupiter, and Titan I ballistic missile systems. W49 warheads were manufactured starting in 1958 and were in service until 1963, with a few warheads being retained until 1975....
, and as a boosted fission warhead without a thermonuclear second stage in several other weapons. These were the Mark 45 ASTOR wire-guided 21 inch, submarine launched heavyweight torpedo; the Mark 101 Lulu nuclear depth bomb
Nuclear Depth Bomb
A Nuclear Depth Bomb is the nuclear equivalent of the conventional depth charge and can be used in Anti-Submarine Warfare for attacking submerged submarines...
; the Mark 105 Hotpoint laydown bomb.
Additionally, an anglicised W34 Python known to the British as 'Peter' was manufactured in Britain as the primary for Red Snow
Red Snow
Red Snow was a British thermonuclear weapon. Its physics package was apparently similar, if not identical, to that of the United States W28 nuclear warhead used in the B28 nuclear bomb and AGM-28 Hound Dog missile, with an explosive yield of approximately 1.1 megaton.The Red Snow warhead was...
, itself an anglicised W28 warhead. Peter was also proposed as a replacement for the Red Beard
Red Beard (nuclear weapon)
Red Beard was the first British tactical nuclear weapon. It was carried by the English Electric Canberra and the V bombers of the Royal Air Force, and by the Blackburn Buccaneers, Sea Vixens and Supermarine Scimitars of the Royal Navy's Fleet Air Arm...
warhead housed in a Red Beard carcass, and as the Violet Mist nuclear land mine for the British Army in Germany.
The W34 used the melt-cast high explosive Cyclotol, a variant of HMX
HMX
HMX, also called octogen, is a powerful and relatively insensitive nitroamine high explosive, chemically related to RDX. Like RDX, the name has been variously listed as High Melting eXplosive, Her Majesty's eXplosive, High-velocity Military eXplosive, or High-Molecular-weight rdX.The molecular...
as the material for its implosion lenses, and this relatively unsophisticated explosive that pre-dated PBX
Polymer-bonded explosive
A polymer-bonded explosive, also called PBX or plastic-bonded explosive, is an explosive material in which explosive powder is bound together in a matrix using small quantities of a synthetic polymer...
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-2 Genie
The Douglas AIR-2 Genie was an unguided air-to-air rocket with a 1.5kt W25 nuclear warhead. It was deployed by the United States Air Force and Canada during the Cold War...
air-to-air rocket
Air-to-air rocket
An air-to-air rocket or air interception rocket is an unguided projectile fired from aircraft to engage other flying targets. They were used briefly in World War I to engage enemy observation balloons and in and after World War II to engage enemy bombers...
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 tritium
Tritium
Tritium is a radioactive isotope of hydrogen. The nucleus of tritium contains one proton and two neutrons, whereas the nucleus of protium contains one proton and no neutrons...
in fusion reactions. The weapons were not tested as extensively as some prior models due to a mid-1960s nuclear test moratorium, and the reliability problem was discovered and fixed after the moratorium ended. The flaw was apparently common with the W44 Tsetse primary
Tsetse primary
The Tsetse was the common design nuclear fission bomb core for several Cold War designs for American nuclear and thermonuclear weapons, according to researcher Chuck Hansen....
design.
Characteristics of these weapons are:
| Python primary based nuclear weapons | ||||
|---|---|---|---|---|
| Model | Max yield (kt) | Diameter (in) | Length (in) | Weight (lb) |
| B28 | 1,450 | 22 | 170 | 2,300 |
| W-28 | 1,450 | 20 | 60 | 1,725 |
| W-40 | 10 | 18 | 32 | 385 |
| W-49 | 1,440 | 20 | 58 | 1,610 |
| W-34 | 11 | 17 | 32 | 320 |
| Possible family members | ||||
| W25 | 1.7 | 17.4 | 26.6 | 221 |
See also
- List of nuclear weapons
- Teller-Ulam designTeller-Ulam designThe Teller–Ulam design is the nuclear weapon design concept used in most of the world's nuclear weapons. It is colloquially referred to as "the secret of the hydrogen bomb" because it employs hydrogen fusion, though in most applications the bulk of its destructive energy comes from uranium fission,...
- Tsetse primaryTsetse primaryThe Tsetse was the common design nuclear fission bomb core for several Cold War designs for American nuclear and thermonuclear weapons, according to researcher Chuck Hansen....
- Robin primaryRobin primaryThe Robin was the common design nuclear fission bomb core for several Cold War designs for American nuclear and thermonuclear weapons, according to researcher Chuck Hansen...
External links
- Beware the old story by Chuck HansenChuck HansenChuck Hansen compiled, over a period of 30 years, the world's largest private collection of documents on how America developed the atomic bomb. These documents were obtained through the U.S...
, 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.
