Really? I did not know that. I thought that I had read somewhere
that nuclear artillery shells used a "linear implosion" kind of effect
- what I mean is a cylindrical rod of fissile material, inside a holow
cylinder of HE to compress it.
A quick bit of googling reveals the W79, which was a indeed "linear
implosion" device, although the implosion is rather more complicated
than I described above!
But I really had no idea gun-type devices were still in service so recently.
Every day is a school day....
On 17 January 2017 at 20:07, George William Herbert
<george.herbert@xxxxxxxxx> wrote:
(Going way OT)
No, you're confusing gun type and linear implosion.
nuclearweaponarchive.com has a FAQ on all this.
The W33 8" gun type artillery shell lasted until the 90s.
Btw, on safeties, the firing mechanism of Davy Crockett's W-54 was just dug
up with config declassified, and a few other goodies.
-george
Sent from my iPhone
On Jan 17, 2017, at 10:42 AM, Pat Bunn <pbunn@xxxxxxxxxxx> wrote:
Wasn’t the linear type (Mark 1) abandoned very soon after the Hiroshima
explosion for safety reasons?
From: arocket-bounce@xxxxxxxxxxxxx [mailto:arocket-bounce@xxxxxxxxxxxxx] On
Behalf Of Andrew Burns
Sent: Tuesday, January 17, 2017 1:33 PM
To: arocket@xxxxxxxxxxxxx
Subject: [AR] Re: Damascus AR Incident
I don't think anywhere in the book he ever argues that a traditional
implosion device has any chance of going off from being on fire for example
but then there are the 'linear implosion' devices that use only two
simultaneous detonators and as he mentions in the book if not designed for
'one point safety' they can possibly generate a very low nuclear yield with
a single detonator going off and you can imagine that happening in an
accident like a plane crash.
Another point he made was that weapons of the time were armed by a simple
electrical pulse signal, an electrical pulse that could conceivably be
generated unintentionally during a mid-air aircraft break-up for example. I
can't remember the exact details but he cites an accident in which a pair of
bombs were dropped accidentally (I think when a B52 broke up mid-air), they
happened to have their lanyards yanked out and as they fell they went
through all of the sequences of events typically preceding detonation like
thermal battery activation, X-unit charging etc. The only thing that stopped
them detonating with full yield was that during the break-up they didn't get
an erroneous pulse of voltage in the right place to arm them. In other cases
weapons were taken off aircraft after an airborne alert and it was noticed
that they were armed despite the arm/safe switch in the cockpit being set to
safe. If the same accident had occurred in this case then the weapons would
have detonated as designed.
My main takeaway from the book was just how uncontrollable and pointless a
full nuclear exchange between superpowers would be, not being an adult
during the cold war it's hard to believe that people ever thought that they
could 'win' a large scale nuclear exchange, especially given that we now
know Russia had a dead-hand system they would enable if war was imminent
that would have guaranteed a retaliation even in the case of a successful
leadership decapitation.
Andrew
On Wed, Jan 18, 2017 at 6:58 AM, David Weinshenker <daze39@xxxxxxxxxxxxx>
wrote:
From: James Padfield <james.padfield@xxxxxxxxx>
Sent: Jan 17, 2017 8:51 AM
To: arocket@xxxxxxxxxxxxx
Subject: [AR] Re: Damascus AR Incident
Perhaps getting a little off-topic here....
I am not so sure I agree. I used to teach a (Masters-level) course on
nuclear weapons (in particular focusing on the explosives and the
explosive train). The assignment I used to set the students was to
research and present on a nuclear weapon accident. Naturally the
Titan II accident at Titusville, along with several others,
particularly the B52 crashes at Thule in Greenland and at Palomares in
Spain, came up regularly. One of the things that I took away from it
every year was that actually it was really difficult to get a nuclear
weapon to detonate unintentionally.
Yeah, it seems like the real risks (at least with the implosion design)
are more related to things like industrial accidents, rocket vehicle
incidents, hazards of handling explosive and radioactive materials, etc.,
rather than an unexpected activation of a fission explosion itself.
(The original "linear gun" design - the "Mark 1"/"Little Boy" configuration
-
was another matter: there was a reason the propellant wasn't loaded into the
"gun" mechanism until the carrier aircraft was safely airborne!)
-dave w
