Ever heard of a cannononball .. ovoid?

[fearn]

Could be, Fernando.

You know how this is going to end, right? Someone's going to have to make a modern cannonball of that particular shape and fire it, just to see if it will fly.

Volunteers?

[fernando]

Originally Posted by fearn

Could be, Fernando.

You know how this is going to end, right? Someone's going to have to make a modern cannonball of that particular shape and fire it, just to see if it will fly.

Volunteers?

That´s what i call a brilliant idea .

Say, you know english better than me; have a look to these extracts:

... The interior of the furnace is lined with fire brick and contains a set of sloping iron rails to hold rows of cannonballs. Rows of iron rods pass through the furnace from one side to the other and are fitted on each end with bolts and "star" braces to support the weight of the shot rails and roof. Cold cannonballs are placed in the furnace and allowed to roll down the inclined rails in rows. The first halls are directly over the firebox at the low end and are heated "cherry red." As they are removed, the next balls roll down into their place and are likewise heated ...

Couldn't the balls prior to the one being heated, start deforming while waiting for their turn, getting the cylindrical shape due to their rolling on the rails ... this assuming that, if the ball being heated reaches "cherry red" temperature, the next ones in the queue must already be half way to it.

... does the cool air tend to reduce the temperature of the cannonball as it flies through the air to the target after it is fired? No. In fact the air friction caused by the cannonball speeding through the air adds to the temperature ...

Something i wouldn't guess!

... The cannonball can even be made to ricochet upon the surface of the water several times without losing enough heat to ignite wood ...

A bit off topic, but this reminds me that, such ricochet method was also used with cold balls, right after portholes were invented and naval artillery could be placed inside the ships decks at sea level. This system brought remarkable advantages for the Portuguese, in naval battles during the discoveries period.

-

[fearn]

re heating cherry red: the thing about these balls is that they're thick. If it's hot on the outside, it almost certainly won't be that hot on the inside.

If it was hot enough to deform, it would droop, not turn egg-shaped. You can run this experiment yourself with a candle, a ball of wax, and something to roll the ball of wax over the flame.

You can also try rolling an egg down a rail, with the long ends on the rails. The egg is going to "want" to spin the long axis, so it's going to twist as it rolls to roll on the short axis. In doing this, it will probably get stuck. So having an oval design isn't going to keep a cannonball on the rails. Round would be simpler.

The thickness of the cannonball will affect how it ignites. For example, if it skips across the water (another place where a spinning round shape works well--see the dam busters), only the part that touches the water will cool, and the heat from the inside will move to the outside. You could get the interesting situation of a cannonball with a cool outer skin hitting a piece of wood, then getting hot enough on the surface to ignite the wood (and this assumes the wood was dry).

Best,

F

[kronckew]

just found this manual: (pdf format)

Gibbon Artillery Manual 2nd ed. 1863

rather extensive tome covering gunpowder and how to make it, artillery history,theory, construction in bronze and cast iron for coastal defence, naval and field artillery, alloys used, casting methods, bore turning, fittings, fixtures, tools, methods of employment, loading, firing, cleaning, spiking, unspiking, testing, etc. etc. also includes use with hot shot, heating shot in furnaces, how use of hot shot varied in differnt countries (french used wet hay wadding) use of sabots, rifling, elongated shot, shells, and even mentions electrical measurements of velocity (odd for 1863) as well as the development of gun cotton in 1846 which proved too strong for the guns and small arms of the time so was abandoned in spite of it's smokelessness...

[fernando]

Grrrreat stuff, Wayne.
Thanks for sharing.
I have just kept it in my files.

[celtan]

This procedure was originated by the inmortal Leonardo DaVinci. The result was a predictable perfectly spherical form.

Best

M

[QUOTE=M ELEY]

Still another possibility is that this is a cannon ball made using the 'shot tower' method. I've included two sites explaining this innovative method of making cannon shot, and although one confesses that the balls produced were perfectly round, I beg to differ. .

www.waymarking.com/waymarks/WM5CD3_Fort_Hayes_Shot_Tower_Columbus_OH
/QUOTE]

[celtan]

Guys, I remember seeing as a child some large ovoid metal shapes lying around in Galicia's ports. I believed initially that they were old cannon balls. I was eventually told by a local sailor that in old times, these were used in sailing boats for balance, "to keep the keel down, and the sail up". Somehow, these ovoid metal bodies were either attached under the boat, or in the lowest internal part of the ship. IIRC, they might have been placed near the keelboard housing.

My two "pesetas".

Best

M

[kronckew]

Originally Posted by celtan

...

see my post no. 24, the writer of that blurb on fort hayes was incorrect in implying cannon round iron shot was made in the tower. they probably made lead balls for cannister and for shrapnel shells, but iron cannon balls, not possible. not enough height for them to cool & solidify before hitting the water, which was to cushion the fall, NOT to solidify the shot. possibly they made round cannon shot there, but if so it was by moulding.

note that the ref. to the baltimore tower specifically mentions the production of iron cannon shot there was by use of moulds.

note the reference link to other world wide shot towers near the top of that page, all of which more correctly only refer to lead shot.

additionally:

In 1783, William Watts of Bristol took out a patent for a process "for making small shot perfectly globular in form and without dimples, notches and imperfections which other shot hereto manufactured usually have on their surface". By pouring lead into a sieve, and letting it cool as it falls, the lead forms into a perfect sphere before falling into a water tank at the bottom.

however, pig iron was frequently used as ballast in wooden ships as you noted, and would have been in whatever convenient sized chunks it was originally cast into. it was stored in the lowest part of the ship to ensure the stability of the vessel by countering any heavy weights (like cannon) above the centre of gravity as well as the lateral pressure of the sails which might have blown it over. (the english 'mary rose' is a good example of what happens when you get it wrong). the captain might on occasion shift the ballast around to 'trim' the vessel to gain an extra knot speed or two, or to improve the stability. cannon balls were of course stowed at the lowest part of the ship and were thus part of the overall ballast.

one of the jobs we had aboard ship, which was there from time immemorial, was to ensure that anything brought on board was stored stably, ballast, fuel, water, food, machinery parts, people, cargo, etc. all have to be stored so as to keep the ship not only level fore and aft, and from one side to the other, but vertically to ensure the stability of the vessel. as a marine engineer, i was trained in not only designing ships, but calculating their stability and how to test that stability. for any who are interested, here is the 'simplified stability testing for small passenger vessels' as an example. the unsimplified version is of course more complex Linky to PDF

as a coast guard marine inspector in new orleans, i actually supervised and approved these kind of tests...

[M ELEY]

No, no, wait! What if the tower was...

Just kidding. I'm one to admit when I'm wrong. Lead shot was made, but I've heard of lead cannon balls in times of desparation. Perhaps with it's low cooling point, they could have been made as such? In any case, our ovoid subject here was not a shot tower ball.

Ballast I suppose seems possible, but I would think that there were much better uses for iron, even pig iron. (early blacksmiths even fashioned tomahawk heads from it). After all, the majority of ballast in the past had been stones, right?

Could this ovoid mass of iron have been used for anything else? A reserve of iron for cannon balls during seiges? As a giant paperweight! Just thinking aloud...

[celtan]

Thank you very much for the explanation. Live to learn!

: )

Originally Posted by kronckew

see my post no. 24,

as a coast guard marine inspector in new orleans, i actually supervised and approved these kind of tests...

[celtan]

Well, we know that vimanas, and UFOs have been reported in several holy books, including the Bible. Works of art in medieval time often depict these drawn in the skies.

It well might be this is a projectile was to be used in a giant slingshot or trebuchet machine, against these pesky visitors?

: )

Originally Posted by M ELEY

No, no, wait! What if the tower was...



Could this ovoid mass of iron have been used for anything else? A reserve of iron for cannon balls during seiges? As a giant paperweight! Just thinking aloud...

[M ELEY]

I know this is a shell, but I'm wondering if this could fit the bill of a double shot for short range?? I've never heard of double shell, but apparently one did exist, so??? It is the right shape. The argument that an ovoid projectile was impractical seems moot judging from this existing projectile.

www.aeragon.com/o/am/index.html

[fernando]

Hi Mark,
Point noted, thanks.
... and link saved intyo my favorits