MH 17 - A Year Without Truth (2015)

EDITED TO ADD..
BOB THIS DERSCRIPTION DOES NOT MATCH THE FILE.
THE FILE IS FOR MH-17 AND THE DESCRIPTION IS FOR SOMETHING ELSE COMPLETELY
FIX IT WILL YOU ;)

the story of the lost nuke... interesting stuff indeed however what has it got to do with MH-17???

also the bomb would not have been armed until just before the it's target... it's a safe guard thing..

PART V: ARMING & FUZING: TECHNIQUES & EQUIPMENT

Overview

The arming and fuzing of nuclear weapons present two distinct and diametrically-opposed problems: on one hand, due to their tremendously powerful combination of explosive, incendiary, and biologically destructive effects, nuclear warheads must never be detonated accidentally.

On the other hand, the arming and fuzing mechanisms must be designed and engineered so that once a weapon is released and armed it will fire. An intact weapon in unfriendly hands can be turned against attackers or disabled or disassembled and copied. For these reasons, arming and fuzing systems must be absolutely foolproof.

By way of definition, the arming system of a nuclear weapon is that portion of the weapon which originates the signals required to arm, safe, or re-safe the firing and fuzing systems, and to actuate the nuclear safing system.

The fuzing system is that portion of the weapon that originates the signal which triggers the firing system. The fuzing system normally consists of radars, baro switches, timers, impact crystals, antennas, and baro sensing elements.

As with all other subsystems in modern U.S. nuclear weapons, the fuzing mechanisms are complex and backed-up by, and interlocked with, other systems. As an example, even the primitive LITTLE BOY and FAT MAN bombs of 1945 had three separate and interleaved parts to their fuzing systems. The main component was a modified U.S. Army Air Corps APS-13 fighter tail warning radar, nicknamed "Archie."

As early as July 1943, possible fuses being considered for the bombs included time clocks, barometric devices, and radio (radar) fuses. An arrangement of two clocks in parallel wired in series with a second parallel pair appeared to satisfy requirements for certainty of operation and safety against inadvertent early arming.

The original radar proximity fuses were to have been built by the University of Michigan and made with commercially-available radio tubes at a frequency of about 100 megacycles.

The prototype arming and fuzing system was to be tested in 14-inch diameter bombs lengthened to 12 feet and equipped with telemetry equipment and smoke puffs fired at pre-set altitudes when the arming and firing system had operated as intended.1

Four "Archies" were used on each bomb, with a network of relays so that when any two of the units signaled, stored current was sent into the detonators (one on the MK I and 32 on the MK III). The antennas for the "Archies" were attached to the sides of the bomb casings.

A barometric pressure-sensing switch closed when the bomb passed 7,000 feet; the bombs were dropped from altitudes between 31,000 and 32,000 feet. A bank of clock-operated timer switches, started by arming wires pulled out when the bomb was dropped, closed 15 seconds after release to prevent the "Archies" from being triggered, in case of baroswitch short-circuit, by radar signals reflected from the delivery aircraft.

The arming and firing sequence for the first two atomic bombs was (1) 15 seconds after release, when the weapon had fallen 3,600 feet, the timer switches closed part of the firing circuit; (2) at an altitude of 7,000 feet, the barometric switch closed another part of the firing circuit and allowed electrical current from batteries in the bomb to charge a number of capacitors and turn on the radar fuses; (3) at an altitude of about 1,800 feet, radar signals emanating from the "Archies" and reflecting from the ground completed the last part of the firing circuit and triggered the detonation signal.

In the MK I LITTLE BOY, the firing signal went directly to the explosive primer that ignited the propellant to fire the uranium-235 projectile into the "target" uranium-235 assembly in the nose of the casing. In the MK III FAT MAN, the firing signal released stored electrical energy from capacitors into detonators, firing the high explosive "lenses" that imploded the plutonium-239 core.

By May 1945, a number of burst heights were under consideration at Los Alamos. The LITTLE BOY might be fuzed for either 1,550 feet or 2,400 feet, depending upon its expected yield of 5 or 15 kilotons. Since delay circuits in the FAT MAN introduced a 400 foot delay in detonation, its fuses were to be set to detonate at either 980, 1,440, or 1,950 feet, corresponding to expected yields of 700, 2,000 or 5,000 tons.

Fuses were re-designed for four different altitudes: 1,000, 1,400, 2,000 and 2,400 feet. These could be used in either type of bomb (LITTLE BOY or FAT MAN); the 1,400 foot fuse looked like the most likely candidate for both weapons.6 .....................
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.......Currently, as many as six different types of safety devices are used together in a single warhead to prevent inadvertent nuclear detonation. Some safety devices, such as inertial switches or accelerometers, will permit arming only when subjected to a specific acceleration for a specified period of time. Arming may also be accomplished by a single highenergy electrical pulse generator when a weapon is released from its delivery vehicle.

source = https://cryptome.org/nuke-fuze.htm