"Artillery 'weights'" Topic

Something I didn't realise the significance of (I knew measures were inconsistent in the Napoleonic era but didn't realise how much variance there was):

"Here the weight measures of the gun calibers (catalogued for the weight of the balls shot) are made simpler using the pdr. (pounders, Pfünder for Austrians). However there were some important differences between French and Austrian measures. Austrian measured weights in Löth, 32 of which made a Wiener Pfund (Austrian pound). 1 Löth was equal to current 17,5g (0.62oz.) so a Pfund was 560g and equal to 1,235lb (Imperial pounds). At least 100 Pfünder made 1 Zentner (56Kg). For example a 3 pdr. austrian light gun was really a 3,7 equivalent French pdr. (more similar to a French 4 pdr.); an austrian 6 pdr. gun was a 7,4 equivalent French caliber and so on."

So an Austrian 3pdr is virtually the same as a French 4pdr, a 6pdr is almost an 8pdr, and a 12pdr would have been the equivalent of 14.8 French pounds. Is there a table anywhere that collates this for the various Napoleonic powers?

From a footnote in link

Cheers,
John

I had a long discussion with Dave Hollins about Austrian artillery, the conclusion was that for cannon ball weights they did not use the Austrian Pound but the Nürnberg pound silverweight.

which is 477, 2 g

@vonW
Thus for the Austrians:
3 pdr = 1.4316 kg = 3.1657 ib
6 pdr = 2.8632 kg = 6.3134 ib
12 pdr = 5.7264 kg = 12.6267 ib

And actually, the classification by pounds was but a convenience.

The actual weight of the single cannon balls was allowed to vary up to around 10%. For example, in Prussia, in 1829, a 6pounder cannon ball had to weight at least 5,5 pounds and not more than 6,5 pounds, a 12pounder cannon ball at least 11 pounds and not more than 13 pounds.

What counted when casting cannon balls, was the exact diameter, which was slightly smaller than the diameter of the bore of the gun and of course corresponded to a cannon ball of ideal cast.

I am surprised that no one has measured and weighed what must be numerous surviving examples of roundshot. There must be a doctoral thesis in this?

what is ib? imperial pounds? what is that in gramm?

The pound weight the Austrians used was lighter than either the French or English pound.

Therefore, the weight of the rounds of an Austrian, French, and English 6-pounder were different, the Austrian being the lightest, the French the heaviest.

A French 4-pounder would be almost a 5-pounder in English weight; a 6-pounder almost a 7-pounder in English weight, an 8-pounder almost a 9-pounder in English weight, and so on.

For a comparison of the different weights and measures of the period, see Volume I of Louis de Tousard's American Artillerist's Companion, pages 116-128:

link

The actual weight of a roundshot depended on the production tolerances that were acceptable.

French tolerances for roundshot was as follows:

24-pounder: 24 pounds, 8 ounces.
16-pounder: 16 pounds, 4 ounces.
12-pounder: 12 pounds, 4 ounces.
8-pounder: 8 pounds.
4-pounder: 4 pounds.

See Tousard, Volume I, page 355.

The weight of roundshot for French artillery pieces in kilograms:

4-pounder: 2
6-pounder: 3
8-pounder: 4
12-pounder: 6
6-inch howitzer: 11
16-pounder: 8
24-pounder: 12

@vonW
Thus for the Austrians:
3 pdr = 1.4316 kg = 3.1657 lb
6 pdr = 2.8632 kg = 6.3134 lb
12 pdr = 5.7264 kg = 12.6267 lb

'lb' is avoirdupois pound (it printed 'ib' in my original post. I used a conversion rate of 1 kg : 2.205 avoirdupois pounds.

Using 477.2 to convert OES Nuremberg pfund to kg, and 453.6 to convert GBR Imperial pounds to kg:

GBR: 3 lbs= 1360.8 gr, Nuremberg: 2 lb 13 oz, Imperial: 3 lb 0 oz.
OES: 3 lbs= 1431.6 gr, Nuremberg: 3 lb 0 oz, Imperial: 3 lb 2 oz.
FRA: 4 lbs= 2000 gr, Nuremberg: 4 lb 3 oz, Imperial: 4 lb 6 oz.
GBR: 6 lbs= 2721.6 gr, Nuremberg: 5 lb 11 oz, Imperial: 6 lb 0 oz.
OES: 6 lbs= 2863.2 gr, Nuremberg: 6 lb 0 oz, Imperial: 6 lb 4 oz.
FRA: 6 lbs= 3000 gr, Nuremberg: 6 lb 4 oz, Imperial: 6 lb 9 oz.
FRA: 8 lbs= 4000 gr, Nuremberg: 8 lb 6 oz, Imperial: 8 lb 13 oz.
GBR: 9 lbs= 4082.4 gr, Nuremberg: 8 lb 8 oz, Imperial: 9 lb 0 oz.
OES: 9 lbs= 4294.8 gr, Nuremberg: 9 lb 0 oz, Imperial: 9 lb 7 oz.
GBR: 12 lbs= 5443.2 gr, Nuremberg: 11 lb 6 oz, Imperial: 12 lb 0 oz.
OES: 12 lbs= 5726.4 gr, Nuremberg: 12 lb 0 oz, Imperial: 12 lb 9 oz.
FRA: 12 lbs= 6000 gr, Nuremberg: 12 lb 9 oz, Imperial: 13 lb 3 oz.
FRA: 16 lbs= 8000 gr, Nuremberg: 16 lb 12 oz, Imperial: 17 lb 10 oz.
GBR: 18 lbs= 8164.8 gr, Nuremberg: 17 lb 1 oz, Imperial: 18 lb 0 oz.
OES: 18 lbs= 8589.6 gr, Nuremberg: 18 lb 0 oz, Imperial: 18 lb 14 oz.
GBR: 24 lbs= 10886.4 gr, Nuremberg: 22 lb 13 oz, Imperial: 24 lb 0 oz.
FRA: 24 lbs= 12000 gr, Nuremberg: 25 lb 2 oz, Imperial: 26 lb 7 oz.

@brechtel

Thx 4 link :)

Note that captured Austrian 6pdrs were designated 5pdrs by the French.

What is your reference for that comment? I'm asking because I am interested.

You know, if this keeps up, I'm going to have to stop mocking moderns players for their continual quibbling over minor differences in caliber and velocity.

At any level of game so low that different weights of 12pd ball are more important than ammo issue or battery organization, crew training becomes far more important than any of this.

It's another 'arrow in the quiver' of overall period knowledge and is interesting and important to some if not all.

Another important measure is barrel length.

At the beginning (Revolutionary) many nations had long versions of their guns – these pieces were heavy but gave long ranges – and would be 'position' pieces.

However, many changed to using the short, or medium, versions – perhaps this reflected tactical changes.

The length of gun tubes changed for the better in Prussia, Austria, and France in the 1740s-1760s, not after the Revolutionary Wars.

And other improvements such as reduction in powder charges, gun tube weight, windage and many other improvements can be taken into consideration.

Calibre is also very important (sizes in British inches)
24pdr = 5.823 (Britain); 6.03 (France & Spain); 5.92 (Netherlands); 6.00 (Russia) 5.93 (Portugal);
12pdr= 4.623 (Britain); 4.78 (France); 4.8 (Spain); 4.76 (Netherlands); 4.76 (Russia); 4.7 (Portugal);
9dr = 4.2 (Britain & Spain); 4.3 (Portugal);
8pdr = 4.18 (France); 4.13 (Netherlands); 4.17 (Russia)
6pdr = 3.668 (Britain); 3.78 (Netherlands & Russia); 3.75 (Portugal);
4pdr = 3.204 (Britain); 3.315 (France);

Above extracted from page 391 in Haythornthwaite's "The Napoleonic Source Book" saying the data taken from "The Bombardier and Pocket Gunner" by R W Adye, London 1802

Regarding the measuring of caliber it is noteworthy that while almost every artillery arm measured caliber by the bore of the piece, the French measured it by the diameter of the roundshot.

I am bringing this post back to life because of a related question I have about the same article linked by the OP, and I will be asking about other aspects of artillery weights (not just shot). At the top of that article's page, Note 4 states that the Austrian 12-pounder artillery was "…effective as a French 8 pdr. gun."

You can say what you want about debating differences in shot weight, it seems like the claim that an Austrian 12-pounder is only as effective as a French 8-pounder bears verifying. The Napoleon Series article is not well identified and seems like a translation. Does anyone know where it came from and who wrote it?

Just as an exercise:
Per Wise, Nafziger and Kiley the French 12-pounder barrel weighed 2172 and 1936 lbs respectively (not sure why such a large difference, I'll defer to Nafziger and Kiley who are both giving the same number). Two of the same sources note the Austrian 12-pounder barrel as being 1790 lbs. So either way, the Austrians used a lighter barrel. Kiley notes the Austrian powder charge at 3.0 and 3.5 lbs, and the French powder charge as 4.5 lbs. So, lighter barrel, smaller charge and just as heavy of a round (or not?). That might set them up for a steeper trajectory and poorer penetration. The article noted above gives no definition for what they mean by "effective." Kiley's book gives first graze numbers that place the Austrian 12 pdr as roughly comparable to the French 12 pdr, and those values are from Adye IIRC. Terence Wise gives numbers that do seem to place the Austrian 12 pdr with a shorter effective range than the French 8 pdr. But again, "effective" is not thoroughly defined.

From Summerfield, Dawson & Dawson page 236 (end note attributes this to Caramna (1830) 'Du Service de l'Artillerie en campagne' in Spectateur Militaire Volume 6 Pages 409 to 462)

"A French officer writing just after the period used Scharnhost's empirical observations and his own experience to state that two French 8pdrs had the same effect as three Austrian 12pdrs; and that five 6pdrs had the same effect as four 8pdrs or three 12pdrs."

From the Napoleonic Wars.Net

"David Hollins
Mar 24

I have seen the comment on TMP about Austrian artillery ranges. It confuses two things: a) the maximum range and b) the range to first bounce at zero elevation.

The maximum range is how far roughly a cannon can fire a ball after a few bounces. This not actually very important as smoke on the battlefield and lack of accuracy, wind, etc. will not result in much effect beyond the first bounce.

The first bounce at zero elevation is affected by the weight of the projectile and the charge, but Austria's powder was considered to be among the most powerful. However, the cannon ball will fly in a parabola, due to gravity at the end, the Bernouli effect (which causes a spinning ball to rise), but above all, it depends on the dispart. The dispart is the angle implied to the bore when the barrel is at zero elevation and arises from the rear end of the barrel being thicker than the front end of the barrel. French barrels were too thick and created a dispart of 1 degree, compared with the Austrian 1/2 degree.

So, a French ball will travel further to first bounce, but that means it will go over some targets than an Austrian ball would hit. Indeed during exchanges at Aderklaa during Wagram, both sides were too close to the other and firing over their targets."

Interesting, thanks for the quote. It certainly doesn't disagree with the article note.

FYI, there are editions of Spectateur Militaire that have been scanned and posted to Google Books. A quick search showed the 1st volume posted by the Austrian National Library, who is a frequent contributor to Google Books. I have previously seen the Carnet de la Sabertache, but not Spectateur Militaire so… always something new to read! Thanks again.

I am more interested in the overall performance of numerous guns over time – like the course of several hours or an entire day. That being said, here are a few comments on Dave Hollins' entry:

- Even if Austrian powder were considered powerful, lighter barrels would typically constrain the pressures that they could operate at. Lower pressure would help contribute (all other factors remaining equal) to lower muzzle velocity, etc. I know he was commenting about a different thread, so just an FYI to readers.

- The Bernouli Effect is a fluid dynamics principle which addresses increases in speed and related decreases in pressure. He might have been thinking about the Magnus Effect, which occurs when a spinning object creates a differential in air pressure on opposite sides. However even then, solid shot would have to be spinning at an improbably high rate, since the very dense and heavy object would require more angular momentum to notably alter its path. I doubt that should seriously be considered for this topic unless solid shot can be demonstrated to have repeatable high spin rates, after being fired out of smoothbore cannon. I am not a physics expert, so I'm perfectly happy to be shown wrong on that, but it just doesn't seem like a notable factor. The Bernouli and Venturi effects would seem to help describe how the lower pressure area (i.e., vacuum) behind the shot could contribute to an increase in the drag force acting on it. But that seems rather different than the noted claim of ball-rise.

- I had thought that the dispart was essentially the equivalent of how modern rifles (for example) are zeroed at certain ranges. It would only affect the solid shot's trajectory as much as it was actually referenced by the senior gun crew. Just like a modern target shooter knows to aim slightly low if firing inside of his (or her) zeroed range, I would expect normally trained artillery crews of the period to know the same (also perfectly happy to be shown wrong on that expectation). Given that expectation, I would be cautious about using examples when the crews obviously failed to make such a basic adjustment as evidence of typical battlefield performance.

Interesting thought: In more modern weapons, those with a shorter zeroed range setting will most commonly be the weapons with the shorter effective ranges. It is interesting how this might play itself out in the shorter zeroed range of the Austrian gun barrels per Dave's reply. Not making any claims here, just sort of a written chin-scratch. Maybe some period artillery experts out there can comment?

@ robert piepenbrink best of luck with such practical ideas in the face of the mountains of petty irrelevant detail that so obsesses wargamers.

I did note above that I am most interested in the overall performance of artillery. So accounts that Austrian 12-pounders are not as effective as French (or other?) 12-pounders by a noticeable margin does seem relevant.

I am however, not shy about spending a paragraph explaining exactly why some other detail may really be irrelevant. Feel free to skip past that part if you are already convinced and sorry for the eye strain.

I find this stuff fascinating

@wtjcom. My sad experience is that the people who are convinced that these 'details' matter will ignore your post and carry on splitting hairs, atoms or quarks in their search for the holy grail for the grand unified equation that proves whatever it is they want to prove. I was trained as a scientist and have a good maths background and there just isn't the data available, even for modern armies, to really assess weapon effectiveness. A French officer says 2 French guns are as good as 3 heavier Austrian ones. Does he provide shot to casualty tables, from several engagements over a range of conditions and do some real statistical analysis, I doubt it and anything else is just military bulls**t [like ordinary bulls**t only with a better polish on it].

That's fine I'll take it.

But I am still interested if anyone has read other artillery accounts as noted above. Thanks in advance.

I'm off to do some more polishing…

I entirely agree we should read any contemporary accounts we can get our hands on, but we should remember that not all of them will be accurate for a whole heap of reasons from 'my career depends on it – Wellington' to simple misunderstandings like Rifleman Harris, who not speaking Dutch came to some unfortunate conclusions at Quatre Bras.