Wednesday, September 20, 2017

Nimrod Was The First Of Those Who Were Mighty On the Earth: The 77mm HV, Technological Progress, And the 1940 Counterfactual

History is, as I never tire of saying, a floating referent. It's never entirely clear where to start, and, in the case of a counterfactual, it is even harder. Hypothetical questions about historical counterfactuals are happening right now, over on Quora.Com, so they are very much questions of 2017. (Just to remind you, the framing counterfactual for this occasional series is,  "What if the Commonwealth armed forces of 1940 were armed like the 21st Army Group on 11 May 1945?") (Also.)

On the other hand, the response is very much to Correlli Barnett's Audit of War, a book that came out in March of 1986, per Paul Addison's review, much linked to from here as an explanation of that book, which the reader may  have forgotten about, or never known. On the other hand again, Audit signifies around here as a programmatic manifesto of Thatcherism, and Dame Thatcher became Prime Minister in 1979, seven years before Audit was published. On the other hand again, Thatcher was famously "a research chemist before she became a barrister," while Barnett had been a military historian/media pundit since the 1960s. Although you'll have to take my word for this, since I am not going to engage the ideas behind Audit in any more detail than is necessary to trace its impact, Audit was exactly what an English research-chemist-turned-barrister born in 1924 in the Midlands would have produced had she turned into an ancestral voice prophesying war, as opposed to, say, a Prime Minister. 

 Finally, just to throw on one more guiding metaphor onto an already unwieldy mass, I have talked about the idea of "Technology Levels," as used in the classic 1977 tabletop roleplaying game, Traveller. I'll come back to "Tech Levels" at the end of this discussion. For now, suffice it to say that they were originally intended to be descriptive. Your party lands on a planet; do the natives, who know you Pappenheimers, shoot back with bows and arrows, or hand-carried fusion blasters? A single number in the planet's descriptor tells you! However, they tend to become prescriptive. A blender from a Tech Level 9 world will be 1/16th (don't ask) more effective at blending than one from a Tech Level 8 world. 
The Zhodani are alien humans (don't ask some more) who are very advanced and psionic and stuff; but they're assholes, for RPG balance. Anyway, they invade the Imperium with their high tech ships, which are just better on account of being higher tech level than Imperium ships. 

Traveller comes before Audit, but Barnett's treatment of World War II is a lot like this. Brits used to say (I take Barnett as saying) that they fought World War II at Tech Level, oh, say, 6.5, compared to Germany's 6. In reality, it was 5.5 versus 6.5, Barnett says. He then adds that, had WWII been fought in 1850, instead, it would have been Britain at Tech Level 5 versus Germany at Tech Level 4, and Britain would have won the war even more than it did. 

So, Britain has gone from a Tech Level advantage of 1, to a disadvantage of 0.5 --in my interpretation, of course. Audit purports to show that this is actually the case, while at the same time fingering the culprits. It's a very ambitious book --far too ambitious, in fact. But it does give us a way to think about technological change. My 1940 counterfactual seems, at least to me, like an elegant way to test this idea about technological change.

And by "test," I mean, stuff the demolition chamber with enough RDX to blow up a planet. (Which, by a wacky coincidence, is more-or-less what we're doing.)
 In an alternate universe, I write a blog post that plays out every detail of a hypothetical counterfactual Battle of France in which British infantry battalions have 16 Bren Gun Carriers and 6 3" mortars, instead of 10 and 3. (And PIATs vice Boys Rifles, 6 pounder antitank guns vice 2 pounders, and so on.) I mean, I have a sense that these things would be important on the ground. I'm also not very clear on how I'd go about writing that, although I will continue to explore it.

Fortunately, there's more than enough to work with starting here, with the Comet tank, the standard British end-of-war cruiser tank, in lieu of 
Things get a bit tricky at the operational level given that the first Cruiser Mark 1s arrived in France via Calais on 22 May. Last time, I got around that by assuming that the motorised division actually attached to the BEF would have been an armoured division in 1945; which is true, but might be deemed to be cheating. I'm not going to go down that route this time, however. Last time, the counterfactual turned into a meditation on the Comet's engine, the Rolls Royce Meteor, which is certainly a fascinating subject in the history of the British engineering industry. 

This time, I am talking about the Comet's gun, the 77mm HV, 

An American-made Sherman tank, modified with a British-made QF 17 Pounder by the Royal Ordnance Factory, Nottingham, and issued to the South Africans who had an armoured division in Italy. By User:Katangais - Own work, CC BY 2.5,

which is also fascinating, and very, very relevant to Thatcher's little revolution. Because she privatised Royal Ordnance, you see.  

The bald story of the 77mm HV is pretty simple. The British Army started the war with a small antitank gun suitable to the tanks around in the day. Anticipating a good, old-fashioned guns versus armour race (actually, 1939 comes in the middle of one, not at the beginning), Woolwich was told to design bigger guns for later introduction. The first of these, the 6 pounder, was introduced into the frontline in 1942, and subsequently manufactured in large numbers in the United States as the 57mm antitank gun. The second, the bloody enormous QF 17 Pounder, was built only in the United Kingdom. Famously, a number of American tanks, the Sherman, were retrofitted with the 17 Pounder and served in the Normandy campaign as the "Firefly." The Comet, being a bit smaller at the top than the Sherman (that's not a criticism), got a slightly cut-down version of the 17 Pounder, contrived by merging elements of the 17 Pounder with an earlier anti-aircraft gun and then cutting down the size and reinforcement of the gun breech in line with the smaller propellant charge. That's your 77mm HV, still more than big enough for 1945, never mind 1940, even if the new 20 pounder (84mm) was hard on its heels in '45. As for the Firefly, it bulks large in the American imagination, because American industry failed to produce an equivalent gun for the Sherman. 
Wikipedia's default image of the American 76mm/L52 (in German parlance, that is, it gets its armour-piercing performance from being 52 calibres long in order to contain more propellant, longer than in a shorter gun like the standard 75mm). By Benzene at English Wikipedia, CC BY 2.5,

Given that America serves as the counter-example to Britain in Audit of War, interesting, you might say. It's been a while since I've read Audit, so I cannot remember how Barnett dealt with this little anomaly, but I assume that it's the way the whole Internet does, which is to treat the Sherman according to the parable of the Model T. You can have cars everywhere, revolutionising everything, or you can have good cars.  That's bullshit, but I've treated the Allied Tank Shortage of 1945 elsewhere, and don't intend to retread that ground today. 

So what makes the 17 pounder so special? Pardon me for cutting-and-pasting some old research (and some old formating), but a big part of the story is very, very simple. If anyone is interested, the text below has gone from Open Office to Word to Blogger. I'm surprised that the software hasn't replaced the original "degree" signs for temperature with the full text of Lord of the Rings, and I am not fixing it, as the clock on the wall says, "work soon."

Volatile chemicals were used in WWII for a number of purposes, including artillery propellants. A distinction is made on the basis of the shock wave propagation velocity between what are known as “deflagrants” and true explosives. The distinction is that in open spaces the velocity of the shockwave is too low to carry actually burning gas, with the result that deflagrants burn, while explosives explode. Various deflagrants are more or less stable in their response to external catalysis,  and compounds containing trinitrotoluene can “sweat” this constituent nitroglycerine, which by itself is most definitely explosive, but deflagrants cannot degrade into explosives. They can, however, have an explosive-like effect when lit in enclosed volumes. Numerous warship magazine fires, some of very destructive character at the Battle of Jutland in 1916 and in 1939–45 resulted from this. Sweated nitroglycerine could and did explode, sometimes with disastrous consequences, although this problem had been virtually eliminated in the British services by 1939.
   Most of the explosives used by the British armed forces in WWII were still trinitrotoluene (TNT), and ammonium nitrate. Production of these on continuous flow basis had been well established in WWI, and although there was substantial increase in productive capacity, development of industrial technique was left to Canadian and American engineers, who developed the batch production method until it was even more efficient than the 20 year old continuous flow method. The need for compact demolition explosives was satisfied by a family of new compounds first explored in the interwar years. In 1920 the German, Herz, prepared the compound RDX, previously identified by another German, Henning, in 1899. Unlike Henning, Herz recognised its explosive power, and published a patent that attracted attention in the United States and the United Kingdom, but only in the latter country was there concentrated work. A small-scale plant was producing 75lb/day at the Waltham Gunpowder Factory associated with the Royal Arsenal Woolwich by 1933, while work went on to improve the synthesis method, which gave a highly impure product. Production was still at the level of only a few hundreds of tons of RDX a year in the autumn of 1941, notwithstanding the opening of one unit at a dedicated factory at Bridgwater in August 1941. Even with the opening of the second unit in 1942, dependence on Canadian and American supply remained heavy, and as with progress in conventional explosives production, it was the North American manufacturers who developed high volume RDX production techniques. Fortunately, the impurities discovered in initial RDX production included other novel explosives of equal value, PETN and HMX. RDX was used in various mixtures by the British armed forces in WWII.[1]
  Propellant gas is far too energetic to be contained by the metal of a gun barrel. The life of the metal at the breech, where the containment lasts longest, may be no more than 10 seconds, although this will correspond to a very large number of firings, from thousands in the case of a shoulder arm to at least more than 100 for a long naval rifle. Nor is the waste energy confined to the barrel. Incandescent gas is expelled from the gun barrel, producing an intense muzzle flash, which dazzles the weapon’s crew and identifies it to enemies during night fighting while contributing to muzzle wear through a back overpressure. The more energetically efficient the propellant, the greater the flash problems. Less energetic propellants, on the other hand, produced excessive amounts of smoke. The traditional gunpowder had long fallen out of favour, and the simplest propellants now used were nitrocellulose (cellulose nitrated with nitric acid) gelled with acetone, or double-base compounds containing a mixture of nitrocellulose and nitroglycerine with greater energy. The original modern brand name propellant (a British imitation of French Poudre B) was referred to as “Cordite,” and the name was perpetuated without distinction when pure nitrocellulose was succeeded in some navies by  double-base, triple-base and even multiple base compounds.  Double-base “cordites” are hotter and thus more energetically efficient. For example, Admiralty standard Cordite MC (65% nitrocellulose, 30% nitroglycerine, 5% cracked mineral jelly stabiliser) had a gas temperature of 3215K and a calorie content of 1025 calories/gramme(?). MC was virtually a better-stabilised descendant of an unstable WWI propellant, but by 1939 several triple-base propellants had become available. Cordite SC was 49.5% nitrocellulose, 41.5% nitroglycerine and 9% symmetrical diphenyl diethyl urea (Centralite), with a gas temperature of 970K and calorific value of 3090. The obvious major virtue of SC was that its lower gas temperature reduced barrel wear, but it was equally important that it could be extruded in high pressure presses, allowing its grains to be accurately sized and shaped cords and tubes. This mechanical modification gave significant consistency improvements. SC cords  in effect improved gun accuracy, while Cordite HSC or HSCK (potassium cryolite replacing Centralite) tubes gave higher muzzle velocity. Unfortunately, all of these propellants were doped with small amounts of chalk to counteract residual acidity, and the resultant calcium gave SC and HSC notoriously bright flashes. 

    During the interwar years intensive research at the Armament Research Department at Woolwich led to the development of a new propellant combining nitrocellulose and nitroglycerine with nitroguanidine (CH4N4O2, first prepared by Jousselin in 1877) and the gelatinising agent nitrodiethyleneglycol replacing acetone. The advantage of the nitroguanidine compositions was that they produced their impetus energy at much lower temperatures (as low as 2100"C compared with 2840"C for pure cordite), greatly reducing barrel erosion, while the new solvent permitted extrusion shaping as referred to above. The resultant so-called triple base propellant NF (55% nitroguanidine, 16.5% nitrocellulose, 21% nitroglycerine, 7.5% Centralite, 0.3% cryolite) was awkwardly bulky, and never available in adequate quantities because calcium carbide is required in the synthesis of nitroguanidine, and its production demanded excessive amounts of electrical power. The sole Commonwealth production facility in Niagara Falls never produced more than 19% of the originally projected output. NF was thus never as widely available as hoped, and this was exacerbated by a decision to supply the US Navy, which had not taken steps prewar to move beyond its traditional all-nitrocellulose cordite. Extrusion plant was also provided, but in inadequate quantities, preventing the U.S. Army from securing a supply of SC. Late war British tanks, using either HSK or some other material, had approximately an 11% advantage in potential muzzle energy compared with tanks still using conventional nitrocellulose at the expense of greatly increased barrel erosion. British performance may be more usefully compared with Japanese and German practice. Both countries used nitrocellulose and nitroglycerine mixes with Centralite and other minor additives, although not solventless-forming methods. The well-known Japanese flashless powder substituted hydrocellulose and potassium sulphate for nitroguanidine and gained the same virtues of flashless affect and disadvantages of excessive charge bulk, albeit to a somewhat greater extent.[2]
The take away here is that the Gunpowder Factory at Waltham Abbey had been working on explosives and propellants steadily through the interwar years, and that Dupont had not. As a result, the British Army entered World War II with a triple base propellant that may, by itself, have sufficed to give British propellants an 11% advantage in energy efficiency over the American Army's pure nitrocellulose formulation. I say "might," because RDX has been used to dope tank propellants for many years, and this could have started with the 17 Pounder, although I wouldn't exactly bet the farm on it. There's no particular reason to assume that this happened, since the sheer amount of propellant in the 17 Pounder cartridge more than explains its ballistic performance, but it might help explain why the Americans had so much more difficulty adapting to the 17 Pounder than to the 6 Pounder. 

The same American industrial decision also accounts for the lack of flashless powder at the Naval Battle of Guadalcanal, problems with adapting torpedoes to modern detonants, and a shortage of RDX. It also might be embarrassing for those who take a simplistic view of how industry works, that America had to import some British extrusion plant. I don't, personally, think that it should be embarrassing. What's radical and revolutionary about asserting that if you don't invest in a technology, you won't have that technology? It's not like Tech Levels are normative. . . 

But enough of that, because, while it is less important than the propellant story, it is important that the British had guns to put it in; and that story comes back to a British, government-owned factory that was privatised under Thatcher, the already-noted ROF Nottingham.  

I spent most of yesterday rummaging through Grace's Guide's pdfs of The Engineer looking for a great interwar article about explosives, and all I could find is this. Maybe it's in Engineering, instead? I'd look, but Engineering makes me sad. And bored. Mainly, bored. 
It's hard for me to go beyond the Wikipedia article; there doesn't seem to be much written on ROF Nottingham on the web, and I haven't struck paydirt elsewhere. Hmm. Engineering does have a cumulative index, unlike The Engineer, at least online. That said, the article covers the basics pretty well. ROF Nottingham was opened as an agency-run National Projectile Factory in 1915, by Cammell Laird. That takes us back to the various "shell crises" of WWI, and a very useful lesson that's going to come up, again: Whatever else we make of sudden armaments crises, they can cause governments to fall. Especially governments that cross Winston Churchill.

Cammell Laird bought the plant in 1923, using it in the 1920s to assemble railway carriages and work on the city of Nottingham's trolley busses. I guess it's not surprising that when the War Office came calling in September of 1936, by-then Metro Cammell Cammell Carriage and Wagon was willing to resell the premises for 94 thousand pounds. The author of the Wiki article draws our attention to the difference between this and the cost of re-equipping the plant, which had reached 1.7 million pounds by the end of fiscal 1937/8. This is less surprising when we notice that Nottingham's first job was building antiaircraft guns,  and the stylised historical facts that Britain had only 180 (large) anti-aircraft guns on 1 January 1938, only 341 at the time of the Munich Crisis that September, and 1500 at the outbreak of war.

On the one hand, that's because the QF 3.7" HAA was a very ambitious bit of engineering in 1938, pointing directly towards the misty future of the Information Age. Or so a crazy guy with a blog might say, long, long ago. (Also.) On the other, I use "stylised" to reference the Sandys Affair, in which Winston Churchill's sometime son-in-law, Duncan Sandys, revealed the shortfall in AA gun production in Parliament, possibly divulging sensitive information captured with the same, secret instant Air Ministry camera that his mistress used to take dirty pictures of two of her lovers. It doesn't get much more louche than this, but, at the same time, the lesson to those who'd lived through the rise of Lloyd George could not be more clear. Build more guns, or lose the premiership to that dreadful Winston fellow. Nottingham was on the spot. 

Again, according to the Wikipedia article, Nottingham's main wartime job was building 40mm Bofors and 3.7" AA guns. Eventually, it built a very great many of them. But, well, here's the quote in full: 

Nottingham made the mobile mounts [of the Bofors] for the British Army from 1938 onwards, and was the main producer of mountings for British ships, including the Stabilised Tachymetric Anti-Aircraft Gun, STAAG. The 2 Pounder anti-tank gun was made at Nottingham from 1937 to 1939. The BL 5.5-inch Medium Gun (1940–42) and the 17 pounder gun, including conversions of the Sherman tank into the 17 pdr armed Sherman Firefly. The hull and suspension units for the first prototype A41 tank, later to be named as the Centurion tank, were built at Nottingham.

It seems as though, in its spare time from making AA guns, Nottingham had a hand in just about every major, successful British artillery project of the mid-war on. (And the STAAG.) What is especially striking is the story of the Comet's gun, in which we encounter plant, and engineers ("no development without production"!) entering the story intending to put the 17 Pounder on the next cruiser tank, deciding that it was too big, veering towards a Vickers gun, abandoning that, and settling with a merger of the 17 Pounder with an improved version of the pre-1935 75mm AA gun that I thought was by then ten years dead and buried. This odyssey through alternative designs and incremental improvements, all shadowed by the fact that, at the same time, work was proceeding towards the 84mm gun of the Centurion, is just such a striking contrast to the catastrophic fumblings of 1938.*

What happened? Actually, I am not sure that the question is justified. After seven years of investment, work, and learning, Nottingham was good at guns. Should we be surprised? I guess that we are; we expect the story to be more like the American failure. But, of course, the American failure occurred in a context where there had not been this incremental investment of money, time and labour. 

There's two takeaways here. The first is that privatisation is not the solution to "public sector inefficiencies." The solution to "public sector inefficiencies" is to make the Prime Minister aware that there are targets and goals to be met, and that if they are not met, that he will lose his job. I don't see much to admire in Duncan Sandys as a person, but he really was doing his job. 

The second is that this particular aspect of technological progress did not happen through some kind of mysterious process in which external forces ratchet up the Tech Level. It happened through investment, production, and development. And, mainly, through production. I promised at the head to talk a bit about the takeaway from Audit of War. Correlli Barnett repeatedly returned to the idea that Britain's problem in World War II was that it lacked college-trained engineers and managers like the ones that staffed American and German industry. Never minding the merits of this observation as history, it is pretty potent prescription. We have, ever since, been, as a species, deeply invested in the idea that investing in STEM education is a way of putting our hands to the Tech Level ratchet. 

The evidence is to the contrary. 

Now I wish that, instead of scraping the image of the visit to Humber-Hillman, I'd taken one of the "waiting room" at a north-of-England engineering firm circa 1937--9, with the cafeteria tables at one end, reading tables for  night class homework in the middle, and drafting boards in the corner. Everything a nineteen-year-old works apprentice might need . . . 

*By which I do not mean to imply that Duncan Sandys was not a generous and sensitive lover.
[1]Akhavan, 10–11, 36; William Hornby, Factories and Plant History of the Second World War; Civil Series (London: HMSO, 1958):112.
[2]P. R. Courtney-Green, Ammunition for the Land Battle (London: Brassey’s, 1991): 1–11; J. Akhavan, The Chemistry of Explosives (Cambridge, U.K.; Royal Society of Chemistry, [1998]): 9–11, 36, 171; E. Freeman, “Thermodynamic Properties of Military Gun Propellants,” 103–32 in Stiefel, ed. 122–27; J. M. Heimerl, “Muzzle Flash Kinetics and Modelling,” 261–310 in Stiefel, ed., 266; Constance M. Green,, H. Thomson, and P. Root, The United States Army in World War II: The Technical Services: The Ordnance Services: Planning Munitions for War (Washington, D.C.: GPO, 1953), 354; John Campbell, Naval Weapons of World War II (Annapolis: Naval Institute Press, 1994; Originally published London: Conway, 1985): 5, 172.

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