Curious stone cannon

[Andi]

A curiosity from ancient China: A stone cannon of the Ming Dynasty at Shanhaiguan Great Wall Museum

[fernando]

Fantastic,
Thinking we already know all that has to be known.
Yet what more we have to know before we die .
Thanks a million for sharing this, Andi.
Will obviously save this picture to my archives.
... Assuming i will never get to visit that museum ... much less the Great Wall .

[Matchlock]

Curious it is, no doubt; fantastic? Possibly ...

How would it have worked, with two touch holes?!
I'm afraid what really puzzles us is the fact that that piece of cannon must have been crudely altered some later time.

Best,
Michael

[fernando]

It seems as these things were not that uncommon in the Great Wall arsenals.
More uncommon appears to be nowaday's knowledge of how they worked in those days

http://www.greatwallforum.com/forum/...te-cannon.html

I still call them fantastic ... almost unbelievable

[Matchlock]

Hi 'Nando,


This one I completely understand: a breechloader with the interchangeable breech missing.

But two touch holes in line??!!


Best,
Michl

[fernando]

I would surmise that the orifice on the back has a different purpose

[Jim McDougall]

Amazing!!! As Nando says, just when we think we've seen it all.
I think back on the perplexing anomaly of the leather cannons of Tibet, and some of the European attempts at light, portable cannon (I think 'light' and portable eliminated their thoughts of this particular material).

In our minds we think of the powerful charge from detonating powder, and how can these cannon fashioned out of less than expected materials withstand those contained explosions. I am wondering if possibly the gunpowder used in earlier times might not have been as potent as of course more modern types.
With admittedly meager understanding of cannon and firearms I am curious.
Michael, you know I'm looking for your key insight here

Also, would these, like the smaller forms of cannon often seen which seem too small to be effective possibly be for signaling and using lesser charge?

Thank you so much for sharing this Andi! as Nando notes, another for the files. Fascinating!!!

All best regards,
Jim

[fernando]

Well Jim,
It is of general knowledge that gunpowder was infinitely less potent in those days (Ming dinasty), as also the signaling hypothesis must not be discarded; indeed they had signaling systems in the wall, so called Beacon Towers.
But i take it that the explanation for this stone cannon phenomenum must reside somewhere else.
It would be great to get enlightened by some of our forum mates ... the first to find out about it .
Without such explanation, i would even wonder whether the loading breech is not occupied with a (shifting) chamber but simply filled directly with gunpowder and closed with a locking lid ... or some other sort of Colombus egg .

.

[kronckew]

Originally Posted by Jim McDougall

...I am wondering if possibly the gunpowder used in earlier times might not have been as potent as of course more modern types.
...

initially gunpowder was a mechanical dry mix of powdered sulphur, charcoal and saltpeter. much less efficient. vibration in transport would also mechanically separate the components to some extent. knowledgeable gunners would re-mix their powder, if they had time, on arrival at the guns emplacement. fine powdered gunpowder also readily absorbes moisture ands loses it 'strength'.

someone in the 14th c. finally figured out that wet mixing the components mixed the disparate chemicals more intimately, resulting in a more efficient bang for your buck (and was safer).

the mix was ultimately corned - formed into grains of various sizes, the grains were screened to standard sizes, larger sizes for cannon, smaller for muskets, smaller still for pistols and the finest for priming. space between the grains allowed for more rapid and even combustion. the grains, even the smaller priming ones, did not absorb moisture near as much as the fine powder. modern powder is usually made (since the 19c) with potassium nitrate rather than sodium nitrate, and is normally coated with graphite to cut down the risk of static sparking.

i recall someone from the period stating that a charge of 18 pounds of properly grained cannon gunpowder was equivalent to 300 pounds of the old powdered gunpowder.

for more detailed info, see

this linky

[Andi]

Here is a very competent group practically investigating the production of medieval black powder, the Medieval Gundpowder Research Group at Middelaldercentret Nykøbing, Denmark http://www.middelaldercentret.dk/pro...gunpowder.html

They also published their experiments on an Open Source base you will find them here http://www.middelaldercentret.dk/pro...ogkanoner.html

[Marcus den toom]

Matchlock, you are right i noticed this too. But when looking better, i wonder if the other side might have a same hole (the picture is taken from the left, but i notice a similiar chisseling at the right side).
Maybe these aren't touch holes but some kind of carrier holes (maybe with sticks to move the barrel around or up and down?)
just trowing something into the discussion.

[Jim McDougall]

Thank you so much guys for adding information on the powder, and Kronckew, thanks as always for such well presented detail. It really helps to get a better perspective on how this might have been used.

I imagined that it might be pretty dangerous being the guys firing this thing! and recall tales of firearms before the use of cartridges being often more dangerous to the guy firing it than the targets. Too much powder and the thing would explode.
Thanks again Andi for posting this and for the links.

Marcus, excellent suggestion I would think for carrying.

Another question...are there any examples of more than one touch hole in cannon? would such a configuration ensure firm detonation?

[Matchlock]

I too am very glad with Kronckew's explanation on early black powder.
I just wish to add that at the beginning from ca. 1300 to 1500, which we call The High- to Late-Gothic period, it was furnished as a very fine meal powder in wooden barrels bound by willow staves and carried in leather bags and thus could easily unmix by transport agitation and get highly hygroscopic thus turning into less effective mixtures and easily getting get wet.
Saltpeter, e.g., mainly came from the animal urine on farm walls. Some 600 to 500 year-old and earlier barrels in my collection and in others still continue to hold their old loads.

The details are from Bartholomäus Freysleben's Inventarium Büchsen und Zeug, cod.icon.222, ca. 1495-1500, fol. 70v and 71r, an armory inventory for the then King Maxilimilan I.


Best,
Michael

[Matchlock]

Originally Posted by Marcus den toom

Matchlock, you are right i noticed this too. But when looking better, i wonder if the other side might have a same hole (the picture is taken from the left, but i notice a similiar chisseling at the right side).
Maybe these aren't touch holes but some kind of carrier holes (maybe with sticks to move the barrel around or up and down?)
just trowing something into the discussion.

Hi Marcus,


I think these cannot be aything else than touch holes because

1. they are drilled vertically while carrying loops for bars etc. would only have worked horizontally.

2. there are small raised recesses cut out behind each of them to act as fireshields for the gunners.


Quod erat demonstrandum: there is one two many touch holes.


Best,
Michael

[Hotspur]

Originally Posted by Matchlock

Curious it is, no doubt; fantastic? Possibly ...

How would it have worked, with two touch holes?!
I'm afraid what really puzzles us is the fact that that piece of cannon must have been crudely altered some later time.

Best,
Michael

The one in the back to lock the breech block?

Cheers

GC

[Matchlock]

Yeah, most probably.

Cheers,
m

[fernando]

Originally Posted by Hotspur

The one in the back to lock the breech block?

Cheers

GC

As i approached in post #6.
To my unexperienced eye, the hole in the back seems to be horizontal.
I reckon i see various holes but only one touch hole.
Also the breech cavity doesn't seem to accomodate a classic rotating cilindrical re(chamber), but rather a squared frame for a lid.
There ought to be an explanation for such an atypical system.

.

[Matchlock]

Exactly, 'Nando,

The hole in the muzzle plate/flat is highly unusual and dangerous, and the lateral damages seem to be rests of former integral stone trunnions, which would make much more sense than drilling a horizontal hole for a transversal bar into granite ...

Best,
Michl

[Matchlock]

With a lot of things said, I'm still facing two severe problems with three seeming recesses in line on the surface; wish I could mark them in red as 'Nando managed to do ...

m

[Andi]

Here is a nice article Lu Mau De - Untersuchung über die Erfindung der Geschütze und des Schießpulvers in China, unfortunately in German language, about the use of early firearms, explosives and cannons in historic chinese literature. There are also pieces mentioned as "Steinkanonen" (stone cannons) but the author did not specify if this are cannons made of stone or cannons for shooting stone balls. But I guess the author means cannons for shooting stone balls.

But the author mentiones lots of other interesting devices like handgonnes with barrels made of bamboo. The Article was published in a periodical Sinica somewhen between 1925 and 1942, unfortunately I was not able yet to sort out the relevant issue.

Many of the holes on the stone cannons are looking like natural cavities in the stone. It is hard to identify touch holes on the fotos.

[Matchlock]

Hi Andi,


I'm sad to say that this article has been outdated long since, for at least 30 years.

Steinbüchsen doubtlessly means pieces of cannon firing stone balls.


Best,
m

[kronckew]

as old as these appear, the 'extra' holes may have been added well after they were no longer used. they are obviously not mounted as they would have been during service, as they are now just propped up on blocks. probably would have had a bit finer surface finish way back then as well. i've seen a sketch of an early breech loader where the breech block was held by a pin thru the centre of the breech with the touch hole forward of the pin hole. the breech block did not contain the charge, just sealed the end. most designs used a wood wedge to tightly force the plug against the breech, and thus has a square section behind the cartridge/breech plug to hold the wedge.

in any case i would likely have preferred being the target than the gunner with that frangible beasty. at least i'd want to be far away when it went off.

only somewhat related, i remember a episode of 'myth busters' where they made a cannon entirely of duck tape that fired an 18 pound ball rather effectively. held up for a few shots if i recall...

[fernando]

Originally Posted by kronckew

... in any case i would likely have preferred being the target than the gunner with that frangible beasty. at least i'd want to be far away when it went off....

Maybe that was the trick; 'abandon' the weapon on the battle field, expecting the enemy to play the smart and fire it back .

[CutlassCollector]

With the extreme thickness of the barrel how would the flame survive the long narrow journey down the touch hole to the charge without going out?
If the touch hole was completely filled with gunpowder would not this be itself an explosive risk due to quantity and the confined space.
Not my area of expertise, although I do enjoy these interesting posts, so forgive me if the question is poor.
CC.

[kronckew]

the powder contains the oxygen required to sustain the burning of the fuse charge, as it is not contained on the open end it burns rather than explodes. stone, being more insulating than bronze or iron/steel would enhance the burning as less heat would be lost to the surroundings. confinement is relative, the larger main charge is bigger than the fuse vent can ventilate, so you get a bang rather than a fizz. as vents wear, in metal cannon at least, they are replaced, drilled out & a new vent screwed in, to avoid loss of propellant gasses. i suspect in a stone cannon the thing would be discarded after the vent wears too big. being ceramic, this is likely still a long life. i'd worry more about it exploding after a limited no. of shots.

p.s. the 'spiking' of cannon so enamoured of authors only temporarily puts a cannon out of action, as the vent is fairly easy to drill out. artillerymen were well aware & usually had tools available. 19c cannon had pre-drilled threaded standardized plugs that could replace a vent in minutes. spiking only gave you enough time to get (hopefully) out of range of your own abandoned cannon before the victors turned them on your retreating selves. abandoning the guns is a shameful disgrace.

one reason the artillery's cannon are their 'colours', like a regiments regimental flag, given by the monarch is defended to the last man and losing your colours (or cannon) to the enemy is a shameful disgrace.

conversely capturing the enemies colours or cannon was the highest act, usually very well rewarded. capturing a french imperial eagle ranked at the top. britain only captured 5 eagles during the Napoleonic wars, 2 of those at waterloo.

[Marcus den toom]

I don't really see the problem with the holes in this cannon.
The breechblock, which is sadly missing, would have had a touch hole. Whih also solves the problem of wear since you just could use a new breechblock.

>1 is behind the actually breech and could never act as a touch hole.
>2 looks to be drilled horizontally or at least at such a shallow slope that it would have emereged at the far end of china before reaching the bore (because once again, the breechblock is missing and can't possibly be connected by drilling a hole at least 20cm in front of the breech).
>3 is the mystery hole i was guessing at. If there is a hole there it would be likely a hole to move this cannon. We don't have measurements, but anyone with a bit of life experience knows that a piece of granit (one of the heaviest of stones) weighs a few "pounds". So logically there should be some way to move the cannon without having a 100 chinees man stampeding against one cannon while the enemy is raining arrows on them. There might have been a lot of chinees in that era as well, but i doubt that they where put to work in such a in effective way.
>Remains hole number 4 which again would come in handy to move a cannon (with a iron bar stuck into it? )

My question is how the breechblock would have been secured? In newer breechloading cannons the breechblock was secured by a bar which was put behind it or just by using wedges which would be pounded behind it.
Pounding near a stone cannon wouldn't be my idea of save working, seeing as a stone cannon is much like a handgrenate and even a small crack in this thing would have caused chinees new year to come earlier than normal (force always seeks the way of lowest resistance).

[CutlassCollector]

I think Marcus may be on the right track. Look at all the lugs on the bronze example. Attachments would have been needed for ropes or bars to locate, aim and absorb recoil on the stone cannon as well.
The breech touch hole makes sense also, instead of having a larger amount of powder which may explode as well as ignite the main charge.

I am sure I have seen pictures of an experimental double firing flintlock somewhere, with two inline locks one in front of the other - hence two in line touch holes - carrying two loads. Really advisable to fire the front one first! Not enough room in this cannon though.

CC

[Matchlock]

Of course it is clear what Marcus has tried to show.

Please see my comprehensive thread on the subject:

http://www.vikingsword.com/vb/showth...h+loading+1440


In my eyes, none of the hole problem is solved though ...


Best,
m

[broadaxe]

Reading this interesting thread I'm seriously doubting this is actually a cannon.
A stone soft enough to be drilled with a simple bow drill and such a small diameter hole, would likely be prone to explode with the smallest amount of gunpowder. On the other hand, a very hard stone such as granite or basalt, was almost impossible to be drilled like that.
This 'cannon' appears to be made of upper crust of limestone (Narry), which is a crunchy substance. The 'breech' area is narrower than the 'barrel', it should have been exactly the opposite. I believe it may be some kind of windlass or mechanical part from an antique industrial facility.