Talk:Naval guns/Research Notes

Tranche 1

• First, and most importantly, it turns out that my supposition (based on looking at the situation as an engineer :-) about the interlocked development of rifling, breech loading and 'conical' shells (well, 'bullet-shaped' - I don't know the proper term to describe that shape) was incorrect! Although rifling, breech loading and conical shells are all synergistic, at least two of them were not introduced simultaneously!

I'm not sure about the shells, because I have not (as yet) turned up much on their development - Hodges has a teeny bit on that, pp. 31-32. (And I'd also like to know how that relates, timeline-wise, to the development of armour.) However, it appears that rifled muzzle loaders came well before breech loading, and were adopted on grounds of accuracy.

Breech loading had been experimented with since Tudor times, but nobody had ever been able to develop an effective seal. The eventually-universal 'interrupted-screw thread' mechanism was invented by the French (Hodges, pp. 14 - no date or name, alas), apparently ca. 1880; the first British ship to be armed with such guns was HMS Colossus, 1887. The original French design, with threads on only 50% of the circumference (Hodges pp. 14) was later improved by the use of multi-level threading, which allowed 75% or so of the circumference to be sealed.

Rifling in large naval guns had been introduced in the 1860s, after experiments showed it to be much more accuate.

• I dipped my nose into a rather recondite work (the Bull/Murphy work) I have on the Paris Gun, as that was based on naval guns, hoping to find something, and I came away with a few interesting factoids - and more importantly, a most important reference (more below).

German naval mounts at the outbreak of WWI were limited to a maximum firing elevation of 30 degrees (B/M, pp. 21, but reprinting an original memo by Rausenberger of Krupp, who developed the German large-bore naval weapons).

It contains a reference to a most valuable source:

Andrew Noble, "Artillery and Explosives: Essays and Lectures Written and Delivered at Various Times", John Murray, United Kingdom, 1906

Google books has this (although something has gone wrong with their watermarking, and every other page has a block at the bottom obscured), and it's a wonderful primary source (Noble was a key naval engineer involved in development in the latter 1800's). I have not yet fully mined this for information, but I will point out what I found to be two particularly valuable papers in the collection:

'Mechanical Science in Relation to the Naval and Military Services' pp 355 (pp 416 of the PDF)

'The Rise and Progress of Rifled Naval Artillery' pp 499 (pp 584 of the PDF)

These have a lot of contemporary technical detail of little utility to us, but the introductory sections of both contain historical overviews which will be very useful. Also, it has lots of good diagrams, and since the copyright it out if we can lay out hands on an original, we can scan in images from that.

Finally, in reading that, I came across references to most interesting-sounding papers by Armstrong and a gentlemen named Vavasseur. Searching for those brought me to this:

Marshall J. Bastable, "Arms and the State: Sir William Armstrong and the Remaking of British Naval Power, 1854-1914", Ashgate, London, 2004

which although it's a secondary source, undoubtly contains much useful information. Alas, I have yet to lay my hands on a copy (although I will definitely acquire one in the not-too-distant future) - at more than $100, it's a non-trivial purchase!

• Hodges (which is not quite a secondary source - the author was a marine weapons engineer, and actually personally trained on the very 15" gun now displayed outside the Imperial War Museum) spends a lot of time on mountings (which is separate from the barbette/turret issue) and also ammunition supply (which is obviously a big issue with shells weighing up to a ton). We won't want to include too much detail here, but we should mention it, as Noble also discusses it a lot, so clearly they were both major issues to the designers.

• I dipped my nose into a number of reference works, and I can confirm that the British 15" twin-gun turret, as fitted to the 'Queen Elizabeth' class, R-class, and Renown/Repulse had a 20 degree elevation limit at that time. (One ref, Campbell pp. 8 says they didn't even have range data above 15 degrees until 1916!) A number of these ships were refitted in the 30's, and the turrets were reworked to provide 30 elevation at that point.

Interestingly, the Renown's original 4" secondary battery did have a 30 degree elevation capability.

• One of those refs (Campbell, pp. 7) refers to a "Welin stepped-screw breech", so that may be the name of the person who invented that improvement (above).

Anyway, that's all I have time for now. Gotta go help with yard stuff for a while. J. Noel Chiappa 10:24, 15 March 2008 (CDT)

Tranche 2

Another tranche of research notes. First, I have discovered a number of other useful sources of information:

• Oscar Parkes, "British Battleships: 'Warrior' 1860 to 'Vanguard' 1950 - A History of Design, Construction and Armament", Naval Institute, Annapolis, 1990
• Percy Scott, "Fifty Years in the Royal Navy", John Murray, London, 1919

The former is a secondary source, but it does contains some material that's directly on point, e.g. a history of the vacillation between rifled and smooth-bore guns. I will go through it carefully and extract research notes. The second is useful in general, although not so much on the rifling/breech-loading issues; Percy Scott was one of the major drivers of increased gunnery accuracy in the Royal Navy. (It also contains some other interesting material, e.g. mention of the Ashanti War, and punitive expeditions up the Congo River before the advent of colonial control.) As an autobiography (from the days before ghost-writers), I suppose it counts as a primary source?

Also, I have gone through the two Noble articles I called out (above). Specific notes are below, but a few overall impressions: Absorbing extremely high recoil forces/energies was a large technical challenge; production of propellants with high energy and low erosion properties was also a major technical challenge. Also, in general, these papers are poor at providing dates - not too surprising, because as contemporary working papers, it's the technology itself that's the focus, not the history.

Noble 1

From: 'Mechanical Science in Relation to the Naval and Military Services', 1890
pp 355 (pp 416 of the PDF)

• pp. 360 - Morsoom's concussion fuses appeared shortly before 1853
• pp. 361 - large wave of technological change starting in 1854, with the revolutions in Europe
• pp. 367 - unsuitability of cast iron as a material for guns; wide use of rifled guns in the US Civil Wara
• pp. 368 - "eccentric shot" as a term for non-spherical solid projectiles; smooth-bores accurate at 300-500 yards, but accuracy went down dramatically long before they reached their maximum range of ca. 3000 yards
• pp. 369 - at a test shortly after 1858 (blast those buggy watermarks! it obscured the exact date) for an increase in range of 35%, the area within which shot landed increased by a factor of three, to 4161 square yards; powder variations were a big part of the cause, causing observed energy output variations of up to 25%; contemporary guns were designed to pierce the heavy armour which was by then common
• pp. 370 - use of ductile steel for barrels
• pp. 371 - recoil energy of contemporary guns is so large that lighter barrels are not desirable anyway
• pp. 372 - high firing pressures are bad as they cause rapid erosion in the barrel
• pp. 373 - range of 13 miles reached with a 9" gun; at 3000 yards a 4.7" gun could put half its rounds in a vertical target of only 4' wide by 5' high; cordite as a very effective propellant

Then there's a lot of stuff about mountings, ammunition handling systems, recoil systems

• pp. 381 - a 5" quick-firing gun fired 5 rounds in 31 second at a 6'x6' target at 300 yards, and all hit

Noble 2

From: 'The Rise and Progress of Rifled Naval Artillery', 1899
pp 499 (pp 584 of the PDF):

• pp. 500 - "In [1858] the Committee on Rifled Cannon recommnended the introduction of rifled Armstrong guns into the service ... With regard to range, accuracy and penetrative power, the superiority of rifled guns was so conspicuous"
  • This is a most interesting comment. Looking at this as an engineer (although admittedly not an aerodynamicist), I cannot conceive how spinning a spherical projectile produces these effects (range, accuracy, etc) - and a non-spun 'eccentric' (i.e. bullet-shaped) shot wouldn't produce these effects either. (It would tumble, increasing drag, and decreasing range and accuracy.) So I am led to conclude that what's being spoken of here is a combination of eccentric shot and rifling. That would definitely produce these effects. Alas, I have yet to find anything which says so directly!
• pp. 501 - at 1000 yards, 1/2 the round smoooth-bore shot landed in 435'x30' rectangle, while for rifled it was 69'x3'; when first introduced, rifled guns produced lower projectile speeds so as to reduce the stress on the barrel; as armour improved, it was necessary to increase the speed of projectives; this need for more speed, combined with slower-burbing powders (to reduce stress on the barrels), required longer barrels, which in turn made muzzle loading less feasible
• pp. 502 - introduction of the bursting shell
• pp. 504 - a 5" gun weighing over 4 tons could be trained by manual force
• pp. 507 - a mounting designed in 1889 that could fire up to 35-40 degrees

The paper then goes on at length about the technical details of a number of current mounting systems, and systems for carrying shells.

• pp. 517 - development of exploding shells, covering fuses, explosives, and effects

That's all for now. J. Noel Chiappa 23:22, 17 March 2008 (CDT)