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Old 10-15-2018, 12:03 PM   #11
hal
 
Join Date: Aug 2004
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Default Re: Black powder Cannon Ballistics in the Age of Sail

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Originally Posted by copeab View Post
Kinetic damage can be estimated with VE2. Recoil impact damage is probably fatal, given the medical technology of the period.
Addenda:



That is a very high velocity for a black powder weapon. The 88mm gun on the Tiger I had a lower velocity than that.

Here is a page with javascript code for calculating velocity. You should be able to use the formula in a spreadsheet with a little work:

https://www.arc.id.au/CannonBallistics.html
Thanks Brandon (it is Brandon right?) The URL is just about what I'm looking for. Since it is an 18 lbr cannon - it looks like the data is already there of sorts.

However, having the data in tons of force against the tackle may be worth using overall. As one person asked me privately in another conversation - just what is the damage that can be inflicted by a cannon's carriage in recoil if the gunners don't get out of the way (such as a cannon hang-firing or someone being jostled by the crew next to them into the path of the cannon etc.

Per Wikipedia (how accurate this is I can't say!) 1 single cwt (long) is equal to 50.802345 kg. A qtr is 1/4 that. So 38.25 x 50.802345 kg = 1943.18969625 kg. Hope that helps clarify things a little.
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Old 10-15-2018, 12:05 PM   #12
hal
 
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Default Re: Black powder Cannon Ballistics in the Age of Sail

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Originally Posted by Fred Brackin View Post
Momentum of the gun and carriage backwards will be equal to the combined momentum of the cannonball, powder gasses and associated things like waddiing.

You'd need separate masses and velocities for all items going forward out of the mouth of the gun and if you have mass and velocity of the cannonball you need nothing else.

If you were dealing with an electromagnetic gun with nothing but a projectile going forward you'd be golden. Unless it was the kind that uses a discarding sabot. :(

Really, you want mass and velocity of the projectile alone and if you're trying for true precision you need that mass in a dependable unit. Are thouse "lbs" avoirdupois (US customary) or maybe Troy or Apothecaries? If you can get mass in grains I think all grains in the above systems are equal.
Best as I can figure, the weight is in Pounds Imperial (Central?) to the extent that a ton is a long ton, not a short ton. Since the Poundal conversion value was based n 10 tons (short), I'm not entirely certain what effect that would have on the overall answer. Will work on it further when I get the chance...

Addenda: When I changed the value from 10 tons to 10 long tons in the conversion application, it gave the poundal as being:

73490.813648294 second^2

Since the charge weight for the gunpowder is 1/3rd that of the ball weight, we're looking at 6 lbs of powder being converted to gas. Should I be using a weight of 24 lbs (the weight of the charge plus the ball)? I don't know how to estimate the weight of the wadding but it can't be all too big of a change over the 24 lbs combined weight of powder and shot.

Last edited by hal; 10-15-2018 at 12:09 PM. Reason: Addenda:
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Old 10-15-2018, 12:30 PM   #13
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Default Re: Black powder Cannon Ballistics in the Age of Sail

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Originally Posted by hal View Post
However, having the data in tons of force against the tackle may be worth using overall. As one person asked me privately in another conversation - just what is the damage that can be inflicted by a cannon's carriage in recoil if the gunners don't get out of the way (such as a cannon hang-firing or someone being jostled by the crew next to them into the path of the cannon etc.
This is for smokeless powder small arms, but it should work for black powder cannons, once you determine velocity. You will need to convert pounds to grains, though (7000 grains per pound). Also, unlike hand-held small arms, friction is a factor on cannon carriages (I don't remember how emplaced guns, unlike towed cannons, have their rear recoil stopped), but you can probably ignore that.

http://www.shooterscalculator.com/recoil-calculator.php
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Old 10-15-2018, 04:34 PM   #14
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Default Re: Black powder Cannon Ballistics in the Age of Sail

Again, if you want velocity, you need to back it out of the ballistic ranges, not derive it from the force.
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Old 10-16-2018, 03:45 AM   #15
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Default Re: Black powder Cannon Ballistics in the Age of Sail

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I don't remember how emplaced guns, unlike towed cannons, have their rear recoil stopped
Heavy ropes attaching them to the hull, I think. Later mountings have the carriage sliding up a sloped ramp to soak the recoil, but that's age of steam era.
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Old 10-16-2018, 03:54 AM   #16
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Default Re: Black powder Cannon Ballistics in the Age of Sail

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Heavy ropes attaching them to the hull, I think. Later mountings have the carriage sliding up a sloped ramp to soak the recoil, but that's age of steam era.
That sounds right. Been several years since I saw a pirate movie ;)
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Old 10-16-2018, 05:30 AM   #17
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Default Re: Black powder Cannon Ballistics in the Age of Sail

Hal, are you sure you can't find the muzzle velocity somewhere? I would think that the Philip j. Haythornthwaite or Bert S. Hall kind of book listed them for Napoleonic cannon and carronades.

In worst case you can estimate it using period tablea for point-blank range and high-school physics. There are such books scanned from Elizabth's day so I am sure you can find them for George III.
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Old 10-16-2018, 05:53 AM   #18
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Default Re: Black powder Cannon Ballistics in the Age of Sail

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Originally Posted by copeab View Post
This is for smokeless powder small arms, but it should work for black powder cannons, once you determine velocity. You will need to convert pounds to grains, though (7000 grains per pound). Also, unlike hand-held small arms, friction is a factor on cannon carriages (I don't remember how emplaced guns, unlike towed cannons, have their rear recoil stopped), but you can probably ignore that.

http://www.shooterscalculator.com/recoil-calculator.php
Naval cannon were attached to the side of the ship with ropes on a block and tackle system - the gun recoiled to the limits of the ropes and they were then used to haul it back out once reloaded.

To be unhelpful, in terms of gun performance, I also recall hearing that the performance of guns changed as they warmed up ... whether that was due to the bore reducing (from fouling and thermal expansion) or what I don't know.

Quote:
Originally Posted by hal View Post
As one person asked me privately in another conversation - just what is the damage that can be inflicted by a cannon's carriage in recoil if the gunners don't get out of the way (such as a cannon hang-firing or someone being jostled by the crew next to them into the path of the cannon etc.
I recall plenty of anecdote about sailors loosing limbs - usually legs or feet - to getting them in the way of a recoiling gun, and am pretty sure that they were easily capable of killing anyone luckless enough to get in their way, but couldn't source that.
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Old 10-16-2018, 07:57 PM   #19
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Default Re: Black powder Cannon Ballistics in the Age of Sail

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Originally Posted by Polydamas View Post
Hal, are you sure you can't find the muzzle velocity somewhere? I would think that the Philip j. Haythornthwaite or Bert S. Hall kind of book listed them for Napoleonic cannon and carronades.

In worst case you can estimate it using period tablea for point-blank range and high-school physics. There are such books scanned from Elizabth's day so I am sure you can find them for George III.
Getting access to the books you mention may be a wee bit problematical... ;)

What books I do have - I try to scour them for any data possible. More often than not, the books I Have purchased with high hopes didn't have what I needed.

Thing is - the amount of energy contained within a given amount of gunpowder should be easily known, as the formula for a given ratio/mixture should be known SOMEWHERE. If you know the charge weight tends to be 1/3rd to 1/4 the weight of the shot, it should be possible to estimate its velocity (which is what it appears that one website that Copeab referenced). I do appreciate everyone weighing in with what they have.

And to tell you all the truth? One person (and he knows who he is) put me back on an old love of mine to the extent that I'm a busy BUSY beaver tracking information down.

Getting stats on Napoleonic era ships isn't too difficult to find. Length, beam, draft, armaments, top speed etc - are easily found. Where I'm running into some minor gaps are the ships from the Age of Piracy - say, mid 1600's on up. I can get tonnage easily enough, and getting some sort of armaments list seems to be somewhat possible. Getting drafts for those ships and such is proving to be a wee bit challenging.

What I hope to be able to do is get a ship's tonnage, its length, its beam, as well as perhaps top speed, draft, crew size etc. It would make for a nice database as a GM to be able to work off of regardless of whether the campaign scenario entails the 1650's, the 1670's, 1725, 1776, or 1794 - let alone 1812.

:)

Much of the details that I seek could be used with say, GURPS SWASHBUCKLERS or perhaps GURPS AGE OF NELSON. I picked up a table top miniatures game for Napoleonic land warfare (useful for GURPS MASS COMBAT), and it might be nice to be able to portray life in the Era of Nelson - especially for a GURPS TIME TRAVEL campaign or what have you.
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Old 10-16-2018, 10:02 PM   #20
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Default Re: Black powder Cannon Ballistics in the Age of Sail

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Originally Posted by hal View Post
Thing is - the amount of energy contained within a given amount of gunpowder should be easily known, as the formula for a given ratio/mixture should be known SOMEWHERE. If you know the charge weight tends to be 1/3rd to 1/4 the weight of the shot, it should be possible to estimate its velocity (which is what it appears that one website that Copeab referenced). I do appreciate everyone weighing in with what they have.
That's not really how internal ballistics works, I don't think. The 'energy contained in' the propellant won't all wind up as kinetic energy of the ball and gun.
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