[Music]
hello everyone and welcome to a short
video on our own devices I'm Jan and
this is a very special episode because
for the first time on this channel I
covering an item sent to me by a viewer
so the awesome Timothy zatara sent me
this little box which while it might
look rather non-descript contains
something really really cool these are
called sleeve jointing self soldering
number three and these were developed
and issued by Special Operations
executive or S soe during the second
world war now s was a secret
organization formed at the behest of
prime minister Winston Churchill in June
1940 shortly after the evacuation of the
British expeditionary force from the
beaches of Dunkirk and it had the rather
awesome Mandate of setting Europe of
Blaze so s soe agents would be
parachuted into occupied Europe and
later the Far East and were working
either alone or more often than not with
local resistance organizations they were
to conduct acts of Espionage
reconnaissance sabotage and subversion
and to this end seoe developed a wide
range of specialized equipment ranging
from the relatively mundane such as
special explosives and detonators for
taking out railroad tracks and
suppressed weapons such as the well- rod
pistol to the truly exotic including
explosive coal for taking out locomotive
boilers and something called cacol Lube
which was a rubber packet originally a
condom filled with Emory powder and this
was designed to be dropped into the oil
tank of a vehicle whereupon the hot oil
would dissolve the rubber releasing the
powder into the lubrication system and
destroying the engine and the vehicle
Beyond repair within a few kilometers of
travel and among all of these creative
gadgets were these so these were
designed to join together the leads
coming off of a blasting cap to set off
an explosive charge to the firing wires
connected to a blasting machine and to
learn more about those fascinating
devices please check out my video on the
subject Link in the description so these
consist of a little copper tube with
flared ends to make it easier to feed a
wire in either side with a slug of solid
solder in the middle and wrapped around
it is a pyrotechnic composition which is
set off by this match head here and this
is a safety Style Match composition
meaning it is split into two parts one
part is on the sleeve itself and
consists of potassium chlorate with a
binder while the other half is the
Striking surface on the box and consists
of red phosphorus so what you do
according to the little instruction
sheet that comes in the box is you strip
off a short section of insulation from
both wires that you wish to join you
shove them into either end of the sleeve
and then using the Box you strike the
match head whereupon the pyrotechnic
composition will ignite heat up melt the
solder and join the two wires and I know
that you're screaming at the screen
right now stop yammering actually set
one of these off well ask and you shall
receive let's actually fire one of these
up and see if it still works so I have
two sections of copper wire here with
the sleeve in the middle held in some
alligator clips and I have a section of
floor tile here to stop the dripping
solder from ruining my table so let's
see how this
works this actually doesn't take a lot
of pressure uh just a light tap with the
Striking surface and as you can see this
Burns without much of a visible flame
which is very useful if you're trying to
set up an explosive charge under the
cover of Darkness indeed seoe also
issued a set of fusee matches of the
exact same composition which were used
to set off safety fuse and other py
Technic devices without giving away your
position or ruining your night vision
and then as it burns you can see the
solder starting to bubble out the end
and solidify and according to the
instruction sheet what you're supposed
to do while the solder is still soft is
grab the wires by the insulation of
course and push them deeper into the
sleeve causing them to cross over and
form a more secure connection but as you
can see from this example that I've
already set off even with the wires just
pushed into either end this forms a very
secure connection and then once the
joint is made what you're supposed to do
is take a pair of pliers and break off
all the remaining slag from the pnic
compound leaving a bare copper sleeve
and then insulate that so that it
doesn't short out so just really neat
little device and really cool idea so as
you can imagine given that these were
developed in secret for use by a
clandestine organiz ation there really
isn't a whole lot of specific
information available about these
although examples that you can find for
sale online are dated as late as the
1960s meaning that these were considered
a good enough idea to remain in service
for several decades after the second
world war there also isn't any
information available on what's actually
inside this pyic composition though I
can make an educated guess you see there
is a very common chemical reaction that
is used in chemistry classes to demonst
exothermic reactions which is the
reaction between iron and sulfur and
this mixture is actually so volatile
that you have to be very careful while
mixing it because the friction can cause
it to go off and typically the mixture
is ignited in a laboratory setting using
a red hot glass rod and as you can see
from this example the two reactions are
nearly
identical and a further piece of
evidence supporting this theory is the
strong smell of sulfur given off by
these sleeves indeed the re reaction
between sulfur and iron produces feris
sulfide which is this black crusty
material and the gas sulfur dioxide
which would account for the smell on the
other hand as I said the mixture of
sulfur and iron is very volatile and
would carry with it the significant risk
of accidental ignition however in order
to make these sleeves suitable for
combat use the pyic mixture would have
to be mixed with some sort of binder to
hold it together and waterproof it and
this would theoretically have the effect
of increasing the activation energy for
the reaction while keeping it low enough
to be set off by a simple match head now
if any of you know exactly what is
inside of these things please sound off
in the comments I would love to hear
your theories or explanations anyway
that's all I have for you today thank
you so much to Timothy Zara for sending
these in I really appreciate it these
are super super cool and just up my
alley for this channel uh one of my
favorite parts of running this channel
is the huge and very supportive
community that has grown up around it so
thank you to everyone who watches and
comments and likes and sends me
suggestions and actual artifacts to
cover I really couldn't do this without
you anyway I'll see you next time on
another video where we'll have a look at
yet more fascinating devices just like
this one until then I'm Jin Mass from
our own devices have a great day