Mythbusters: The Leather Cannon
David E. Powell
cannons made with or reinforced with leather.
The first was Gustavus Adolphus' built up Swedish 17th Century cannon,
a light piece built around a copper tube for a barrel, with glued and
laminated cloth, a few iron rings, and finally a layer of leather.
A design recognizable today in the age of composites, it reminded me
of a Ruger design I saw with a steel sleeve barrel which was
reinforced with composite layers.
The second design was entirely leather, and based on an Irish all-
leather cannon.
The first design worked pretty well. They blew out the breech plug but
said it was the first build and surely they would get better at that
if they kept making them. It actually beat the velocity of a Parrott
rifle of 1860s vintage with an equal powder charge. The Swedish cannon
seemed to work pretty well.
The all-leather cannons didn't do well. the first popped the ball out
a few feet but blew out the back. The second, with a more reinforced
breech which was braced with leather straps looped over the back and
laminated in place, with a "Dahlgren Gun" or "Parrott Rifle" style
look which may have been influenced by the Parrott rifle they saw.
That one got up to about 53 MPH with the cannonball but not much
better, due to internal warping and possible unraveling of the leather
layers.
Given that the weight of cannon on ships could be a worry stability
wise, I wonder if Gustavus Adolphus ever mounted leather cannon on his
ships? It seems a neat way to get a lighter gun deck or maybe a couple
of extra guns on board.
The charge the cannons on the show used was standard at 6 ounces of
black powder.
Kerryn Offord
> The other night on Mythbusters Buster's Cut, they looked at ancient
> cannons made with or reinforced with leather.
>
> The first was Gustavus Adolphus' built up Swedish 17th Century cannon,
> a light piece built around a copper tube for a barrel, with glued and
> laminated cloth, a few iron rings, and finally a layer of leather.
>
> Given that the weight of cannon on ships could be a worry stability
> wise, I wonder if Gustavus Adolphus ever mounted leather cannon on his
> ships? It seems a neat way to get a lighter gun deck or maybe a couple
> of extra guns on board.
>
> The charge the cannons on the show used was standard at 6 ounces of
> black powder.
The leather cannon used by Gustavus was a 3lbr.. and was an early try at
getting a really light Regimental (?? or Battalion??) gun to increase
the firepower of his infantry formations.
He quickly replaced the leather design with proper designs (iron or bronze)
One problem with a "leather gun" is it doesn't deal well with sustained
fire.. the sort of fire that gets the barrels really really (colour
changing?) hot...
So, no. I doubt Gustavus ever mounted leather guns on his ships...
There are also likely to be scaling problems.. you can make a 3lbr with
that design, but what about a 18 pdr?
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William Black
Several problems here.
First of all powder in Gustavus Adolphus' time wasn't as quick burning
as today, second we don't know exactly how the leather guns were built,
third they seem to have needed rebuilding between engagements and
fourth, he dumped them for something more conventional as quickly as he
could.
You don't say what the bore of these things was but a saker of the
period (roughly a 3 inch bore, but it varied) used a powder charge of a
couple of pounds of powder or more.
--
William Black
Free men have open minds
If you want loyalty, buy a dog...
Jeff Crowell
> He quickly replaced the leather design with proper designs (iron or bronze)
>
> One problem with a "leather gun" is it doesn't deal well with sustained
> fire.. the sort of fire that gets the barrels really really (colour
> changing?) hot...
>
>
> So, no. I doubt Gustavus ever mounted leather guns on his ships...
>
> There are also likely to be scaling problems.. you can make a 3lbr with
> that design, but what about a 18 pdr?
Hope the durn thing doesn't get wet! :-D
Jeff
--
Rules of Flying:
The three things most useless to a pilot are air above, runway
behind, and a second ago.
Kerryn Offord
Don't ask for a url.. Can't remember it.
"Leather guns and other light artillery in mid-17th-century Scotland
by David Stevenson and David H Caldwell" p.300
"Wurmprandt's guns were used by Swedish armies for several years; their
use is sometimes said to have been discontinued by 1629 (e.g. Roberts
1958, II, 232), but some were still in use at the battle of Breitenfeld
in 1631 (Hime 1898, 597n). Nonetheless, the career of the Swedish
leather gun was short, for it had 'sacrificed everything' to lightness
and mobility; 'for fear of splitting the barrel it had to be provided
with special powder and a much reduced charge, with resulting loss of
muzzle-velocity and range; but even so it was much too fragile' (Roberts
1958, II, 232-3). Additional disadvantages were that the complexity of
the gun's construction led to manufacturing difficulties, and the fact
that the rope and leather covering of the metal barrel provided good
insulation meant that after firing a few rounds the barrels became too
hot to load safely (Wijn 1970, 218; Carman 1955, 63; Roberts 1958, II, 233).
"
(I can expand on the references (They are listing in the article
bibliography))
David E. Powell
Good point. They seemed to be using modern re-enactor grade stuff.
second we don't know exactly how the leather guns were built,
True, they went as close as they could do some documents on the
Adolphus cannon, but the all leather cannon were basically improv
builds.
> third they seem to have needed rebuilding between engagements and
> fourth, he dumped them for something more conventional as quickly as he
> could.
>
> You don't say what the bore of these things was but a saker of the
> period (roughly a 3 inch bore, but it varied) used a powder charge of a
> couple of pounds of powder or more.
I believe they were about 3 inch in bore, with all firing equivalent
projectiles and charges.
William Black
I looked it up.
A Saker, 3" to 3.5" bore, used between 2.5 and 4 pounds of powder.
'Eldred' is usually taken as about the best source of the time in
English and he says 4lb in a saker of 3.5" bore
http://www.dimacleod.co.uk/history/glass.htm
So their 6oz of powder is a joke...
Re-enactors tend to use firework powder which is not terribly well
graded, lots of odd shaped lumps, and so it is lousy for actually
shooting at things, but it IS cheap.
Jeffrey Hamilton
An interesting post Kerryn, so I googled the title you gave and found this
page, it is a pdf document, 21 pages in length and seems to begin at page
300, enjoy all.
http://archaeologydataservice.ac.uk/catalogue/adsdata/PSAS_2002/pdf/vol_108/108_300_317.pdf
cheers.....Jeff
Kerryn Offord
But that is period BP and a 2700 lb piece...
The "leather" guns were ultra-light artillery and as per
(Thank you for finding the url, Jeffrey)
http://archaeologydataservice.ac.uk/catalogue/adsdata/PSAS_2002/pdf/vol_108/108_300_317.pdf
"the career of the Swedish leather gun was short, for it had 'sacrificed
everything' to lightness and mobility; 'for fear of splitting the barrel
it had to be provided with special powder and a much reduced charge,
with resulting loss of muzzle-velocity and range; but even so it was
much too fragile'"
Mythbusters tend to use commercial musket BP..
Remember, in the US they even have a BP hunting season in some areas...
so they have a market for good quality BP... which will tend to be small
grained...
William Black
>
> Mythbusters tend to use commercial musket BP..
>
That'll burn far too fast for cannon use.
You'll blow the back out of it.
Reports indicate that, erm, they did...
Mark Borgerson
willia...@hotmail.co.uk says...
> On 01/08/10 00:33, Kerryn Offord wrote:
>
> >
> > Mythbusters tend to use commercial musket BP..
> >
>
> That'll burn far too fast for cannon use.
>
> You'll blow the back out of it.
>
> Reports indicate that, erm, they did...
>
>
A slight change of topic. On the 4th of July, I assisted
my brother--in-law at a fireworks show after a minor-league
baseball game. The fireworks aren't the topic of interest,
though. Before the fireworks a local National Guard
artillery team fired saluting charges from a 105MM howitzer.
There was a lot of white smoke. Are those charges the
usual smokeless powder without a shell, or are they black powder?
Along the same lines, were naval salutes from muzzle-loading
cannon fired with special powder and reduced charges, or did
they (hopefully), just not load the cannonball?
Mark Borgerson
Kerryn Offord
> On 01/08/10 00:33, Kerryn Offord wrote:
>
>>
>> Mythbusters tend to use commercial musket BP..
>>
>
> That'll burn far too fast for cannon use.
>
> You'll blow the back out of it.
>
> Reports indicate that, erm, they did...
>
http://www.powderinc.com/blackpowder.htm
Looks like you can buy it in "cannon" grade...
Paul J. Adam
<willia...@hotmail.co.uk> writes
>So their 6oz of powder is a joke...
>
>Re-enactors tend to use firework powder which is not terribly well
>graded, lots of odd shaped lumps, and so it is lousy for actually
>shooting at things, but it IS cheap.
I've had the occasional chat with the Fort Nelson display teams. One of
their requirements is a big loud smoky bang. The other is that they
don't do anything to the gun that a good pulling through won't fix.
Finally, they want to be very safe indeed while still making a decent
show. Firework powder fits the bill very nicely.
For firing artillery in front of the general public, the less effective
the powder is at actually propelling projectiles the better: Murphy says
that one day, someone will leave a bore brush in the barrel and the
display blank will launch it along Portsdown Hill to maim someone in the
queue for Mick's Monster Burger Van.
Regarding Mythbusters, it's great fun and I like it a lot, but they've
taken to occasionally having the "liability insurance says no"
conversations edited into the show to point out that they're
technically-minded entertainers working within the art of the possible
for a one-hour (with commercials) TV slot, not archaeological purists.
Bursting guns used to kill people, sometimes in double-figure batches,
so of course they'll play it safe...
--
He thinks too much, such men are dangerous.
Paul J. Adam
William Black
> In message <i3134u$rdj$1...@news.eternal-september.org>, William Black
> <willia...@hotmail.co.uk> writes
>> So their 6oz of powder is a joke...
>>
>> Re-enactors tend to use firework powder which is not terribly well
>> graded, lots of odd shaped lumps, and so it is lousy for actually
>> shooting at things, but it IS cheap.
>
> I've had the occasional chat with the Fort Nelson display teams. One of
> their requirements is a big loud smoky bang. The other is that they
> don't do anything to the gun that a good pulling through won't fix.
> Finally, they want to be very safe indeed while still making a decent
> show. Firework powder fits the bill very nicely.
>
> For firing artillery in front of the general public, the less effective
> the powder is at actually propelling projectiles the better: Murphy says
> that one day, someone will leave a bore brush in the barrel and the
> display blank will launch it along Portsdown Hill to maim someone in the
> queue for Mick's Monster Burger Van.
>
You do get the odd ramrod winging its way in the general direction of
somewhere else.
Usually when someone doesn't 'guard the vent' properly.
But not at Fort Nelson where there are some nice high banks to stop them.
I remember being at an event at a major stately home when a ramrod
skewered a Mini from front numberplate to back...
William Black
UK regulations require that black powder in quantities over 25Kg have to
be delivered in a vehicle suitable for its transport.
Most societies buy it in bulk and break the bulk stuff into bottles at a
registered 'factory', which is usually a field owned by a society member.
A company of musketeers shoots a couple of pounds off every volley.
Paying that kind of money for powder for a cannon that shoots a pound of
the stuff off every bang isn't economic. Something saker sized needs a
couple of pounds.
A major event can get through 150 to 300 Kg of the stuff.
Anyone who's buying black powder retail isn't in re-enactment...
Andrew Chaplin
> In article <i32c9i$2i...@news.eternal-september.org>,
> william.bl...@hotmail.co.uk says...
Depending on supply source, 105 howitzer blank cartridges, both full
and reduced, are typically black powder in the M14E1 case, which is
also a case used for service ammo, but with a longer primer for
service propellants. Recently I saw a salute fired in Ottawa with a
reduced charge with a truncated cartridge (I cannot recall the model)
and it also produced a lot of white smoke compared to the rounds used
in the 1970s and '80s.
--
Andrew Chaplin
SIT MIHI GLADIUS SICUT SANCTO MARTINO