one it takes more then flipping a switch to arm a nuke.
you have to have a code and it has to be entered into the weapon by two people.
this can be done from the cockpit of the aircraft.
on some nuke weapons there is a second part that must be done and that is one of the explosive lens must be moved into place in the weapon for it to
this also can be done from the cockpit with a special code.
all this is done so that the chance of a weapon going off by accident is below .0000001%
if i see a nuke mushroom i know it was not a accident.
From the very first nuclear weapons built, safety was a consideration. The two bombs used in the war drops on Hiroshima and Nagasaki posed significant
risk of accidental detonation if the B-29 strike aircraft had crashed on takeoff. As a result, critical components were removed from each bomb and
installed only after takeoff and initial climb to altitude were completed. Both weapons used similar arming and fuzing components. Arming could be
accomplished by removing a safety connector plug and replacing it with a distinctively colored arming connector. Fuzing used redundant systems
including a primitive radar and a barometric switch. No provision was incorporated in the weapons themselves to prevent unauthorized use or to protect
against misappropriation or theft.
In later years, the United States developed mechanical safing devices. These were later replaced with weapons designed to a goal of less than a 1 in a
1 million chance of the weapon delivering more than 4 pounds of nuclear yield if the high explosives were detonated at the single most critical
possible point. Other nations have adopted different safety criteria and have achieved their safety goals in other ways.
In the 1950’s, to prevent unauthorized use of U.S. weapons stored abroad, permissive action links (PALs) were developed. These began as simple
combination locks and evolved into the modern systems which allow only a few tries to arm the weapon and before disabling the physics package should
an intruder persist in attempts to defeat the PAL.
Safing To ensure that the nuclear warhead can be stored, handled, deployed, and employed in a wide spectrum of intended and unintended environmental
and threat conditions, with assurance that it will not experience a nuclear detonation. In U.S. practice, safing generally involves multiple
mechanical interruptions of both power sources and pyrotechnic/explosive firing trains. The nuclear components may be designed so that an accidental
detonation of the high explosives is intrinsically unable to produce a significant (>4 pounds TNT equivalent) nuclear yield; it is simpler to insert
mechanical devices into the pit to prevent the assembly of a critical mass into the pit or to remove a portion of the fissile material from inside the
high explosives. Mechanical safing of a gun-assembled weapon is fairly straightforward; one can simply insert a hardened steel or tungsten rod across
a diameter of the gun barrel, disrupting the projectile. All U.S. weapons have been designed to be intrinsically one-point safe in the event of
accidental detonation of the high explosives, but it is not anticipated that a new proliferator would take such care.
Arming Placing the nuclear warhead in a ready operational state, such that it can be initiated under specified firing conditions. Arming generally
involves mechanical restoration of the safing interrupts in response to conditions that are unique to the operational environment (launch or
deployment) of the system. A further feature is that the environment typically provides the energy source to drive the arming action. If a weapon is
safed by inserting mechanical devices into the pit (e.g., chains, coils of wire, bearing balls) to prevent complete implosion, arming involves removal
of those devices. It may not always be possible to safe a mechanically armed device once the physical barrier to implosion has been removed.
Fuzing To ensure optimum weapon effectiveness by detecting that the desired conditions for warhead detonation have been met and to provide an
appropriate command signal to the firing set to initiate nuclear detonation. Fuzing generally involves devices to detect the location of the warhead
with respect to the target, signal processing and logic, and an output circuit to initiate firing.
Firing To ensure nuclear detonation by delivering a precise level of precisely timed electrical or pyrotechnic energy to one or more warhead
detonating devices. A variety of techniques are used, depending on the warhead design and type of detonation devices.
Depending on the specific military operations to be carried out and the specific delivery system chosen, nuclear weapons pose special technological
problems in terms of primary power and power-conditioning, overall weapon integration, and operational control and security.
Not all weapons possessors will face the same problems or opt for the same levels of confidence, particularly in the inherent security of their
weapons. The operational objectives will in turn dictate the technological requirements for the SAFF subsystems. Minimal requirements could be met by
surface burst (including impact fuzing of relatively slow moving warhead) or crude preset height of burst based on simple timer or barometric switch
or simple radar altimeter. Modest requirements could be met by more precise HOB (height of burst) based on improved radar triggering or other methods
of measuring distance above ground to maxmize radius of selected weapons effects, with point-contact salvage fuzing. Parachute delivery of bombs to
allow deliberate laydown and surface burst. Substantial requirements could be met by variable HOB, including low-altitude for ensured destruction of
protected strategic targets, along with possible underwater or exoatmospheric capabilities.
[edit on 3-12-2008 by ANNED]