Also known as the B-41, the Mk-41 was the
cold war bomb most likely to spring to mind when one thought of
The Bomb, for it was the most potent free-fall nuclear weapon developed and fielded in large quantities by the US. It weighed almost 5,000kg and was the size of a small truck. In its most destructive form, it would have rendered the
United Kingdom uninhabitable for centuries, had the
USAF chosen to drop a live, fused bomb onto Wales. Alternatively, an MK-41 could have erased Luxembourg forever. Without becoming bogged down in technical detail, the Mk-41 was a 'three-stage'
thermonuclear device, utilising a small
fission weapon to create the requisite temperatures to allow nuclear
fusion, which in turn created enough high-energy neutrons to generate fission in a turbocharging '
tamper', in the case of the Mk-41 either
U-238 or lead.
Fitted with a U-238 tamper the Mk-41 was a hugely destructive, 'dirty' bomb, producing energy equivalent to roughly 25 Megatons of TNT, along with a great deal of radiation. With a lead tamper the Mk-41 was half as powerful and much cleaner, the lead acting as a choke on the final fission reaction. The Mk-41 was an advanced, experimental design, in development from the mid-fifties until 1960, at which point it entered production. Within two years, five hundred of the bombs had been made. It was deployed in late 1962, only to be retired in phases from 1963 to 1976. Although impressive, the Mk-41 was more a proof of concept than a practical weapon, the concept encompassing the mass-production of what remains the most awesome weapon produced by the free world.
It was too large to be sat atop a contemporary missile, and was therefore to have been dropped by the B-47 Stratojet and the B-52 Stratofortress, the latter by now having outlived most of the free-fall nuclear weapons it was designed to carry. In theory the bomb could also have been carried by the B-36 Peacemaker, although the B-36 was retired shortly before the Mk-41 entered service. The ill-fated B-70 Valkyrie was also mooted as a means of deliverance, although the Valkyrie's bomb bays became too hot during supersonic flight for safe carriage of the Mk-41. Neither the B-58 Hustler nor the F-111 had the payload capacity to carry the Mk-41 and the B-1 did not coexist with it.
Why this monster? The reasons for the Mk-41 were as much psychological as military, for it was not just a highly destructive bomb; it was a highly destructive, mass-produced bomb, hundreds being built before production ceased. The Russians produced several spectacular explosive devices, including the biggest bomb ever made - the 'Tsar Bomba' - but these were not practical propositions. The Mk-41 was not just built, it was deployed actively. Ostensibly its great power was to be harnessed for the destruction of buried arsenals, missile silos and command bunkers rather than major population centres, against which it would have been ridiculous overkill, rather like the 'Death Star' of Star Wars. For a nuclear weapon to destroy a city it is not required that the weapon totally obliterates all structures, merely that it causes the disruption of infrastructure and the death of the civilian population.
As an anti-bunker weapon the Mk-41 was of limited use; it could survive parachute impact with the ground, but was not designed to penetrate either soil or concrete. In our world the concept of an actual nuclear bomb seems anachronistic, the hot new sinister field of the 1970s being submarine-launched ballistic missiles, miniature spacecraft of the type which had made John Glenn and Alan Shepard famous (indeed, the early Mercury capsules had been launched atop ICBMs). Yields are much lower now, the missiles tending to carry several independent kiloton bombs, indeed neither the US nor any European nation currently possess multi-megaton weapons, although the blueprints and calculations are still in the archives.
I love the bomb. I am an only child, and my big brother was the bomb:
http://nuclearweaponarchive.org/Usa/Weapons/B41.html
http://www.strategic-air-command.com/weapons/nuclear_bomb_chart.htm
http://www.johnstonsarchive.net/nuclear/multimeg.html
http://www.uscoldwar.com/histry_warhead.htm
And much of FAS and so forth, you know.