To whom it may concern: Rick Orli is a new member here on Graybeard and the owner/moderator of Zagloba's Tavern and owner of Kismeta Polish Horse Artillery site. He posted this with Yahoo Group, SCA-Gunners and Yahoo Group Zagloba's Tavern.
I suggested he post it here as you can read in the thread. He has given me the green light to do so but my not being an expert at this like a moderator, it's a crap-shoot. Sometimes I win and sometimes I loose.
So here goes nothing:
Re: Cannon safety test
Greybeard? don't recognize that. If there is a place I should post the info,
please let me know (or feel free to copy and paste)
-Rick
>
> Rick,
> This belongs on Graybeard with the images. Why the limited exposure of text on
Zaglobastavern and inages on SCA-Gunner? Some of us have been waiting. There is
an interest.
>
> Rich
>
> --- In zaglobastavern@yahoogroups.com, rotmistrzb <no_reply@> wrote:
> >
> > Recall earlier discussion of an accidental discharge, blamed on a stray
ember. I thought that would not happen if the charge had been properly made.
> >
> > My controled test was run monday, in which I tried to determine how long it
would take to ignite a black powder charge with a red-hot charcoal brickette, if
protected by a charge casing constructed of exactly 2 layers of heavy duty
kitchen foil.
> >
> > I posted pictures in the SCA gunners list...3 pictures are in photos/kismet.
One showing the setup - the shape of the
> > charges which were constructed, and the container, an alum. coke can bottom
1/3.
> >
> > I wanted a metal container to keep the charge seated on the coal and the
heat concentrated as it might in a gun tube. On the other hand I did not want to
contain gases which might cause an explosion so the can was kept short.
> >
> > The charge bottom is exactly 2-layers of heavy duty foil, using my
cannon's(kismet's) charge shaper/mold(shaper pressed down into the center of a
sheet, so that the bottom would not have any folds), and a half ounce of 1F
black powder (this was about 1/3 inch thick powder layer), goex, fresh can.
> >
> > The second picture shows how the charge fits inside the container: about 90%
close fit.
> >
> > I removed 2 charcol bricketts from the middle of a grill, which were by my
best judgement at peak heat. They had been heating about a half hour, and were
fully covered in ash and glowed a fairly uniform dull red. these were removed by
thongs and placed in the 2 test containers. and within 20 seconds I put the
first charge on and 5 seconds later the second charge.
> >
> > I noted the time and stood clear. The 3rd picture showes the test in
progress. After 15 minutes passed and neither charge had ignited, I terminated
the formal test, concluding that the coals had cooled and there was little
prospect of ignition. Nevertheless, for safety reasons I did not approach the
test setup until approximatly 40 minutes passed, at which time I lightly hosed
down the
> > setup from a distance. 20 minutes later I approached the setup and poured
enough water to fill the container, and found (somewhat to my alarm) that the
coals were still hot enough to boil the water I added and that the powder charge
was still being heated.
> >
> > In conclusion, 2 layers of foil seem to entirely protect a charge from
> > accidental ignition from coals. In reality, an ember in a cannon would not
be nearly as large, hot and long burning as a charcol brick, and anyway it would
only need to protect the charge from igniting for a minute or so, to allow
completion of the loading process.
> >
> > A properly made foil-wrapped charge with not 2 but at least 3-4 layers of
foil seems essentially proof of any risk of accidental discharge by an ember. I
don't know what caused the accident, but it was not 'only' a stray ember.
> > -Rick Orli
