Tuesday, October 29, 2013

Running Away to the Air, 8: Planes for Ships. A Dialogue

I start with an apology. This is a response to an argument that ChrisM put forward in an email. I'll cite below, but there is a pretty severe power imbalance between a correspondent and a Big Giant Blog Writer. On the other hand, I've got long-mouldering Evidence to put out there. So there's that.

So. You say you want to grow up to be First Sea Lord.

I'm listening. I certainly don't want to be the nay-sayer. It's a colourful title that comes with a peerage, a nice pension, and the prospect of interlocking directorates in profitable publicly-traded corporations. What's not to like? A young naval officer should aim for the title. (Unless he is a doctor, accountant, or instructor. Or an engineer? I'm not sure about the last. Have we decided whether they're supposed to aspire to be Engineer Vice-Admiral, First Sea Lord, or both. Will we change our minds?)

And you did such a splendid job of picking your parents, too! Famous, influential at court, an uncle who is an admiral himself, carefully edited out of your Wikipedia biography to avoid clouding the issues. But there's one small roadblock and one huge. The first roadblock is that you've decided against the gunnery specialisation. You've been at Dartmouth long enough to see the numbers that every young man crunches. Your chances are better in Gunnery. That being said, we all know that it is a small roadblock, because if you are good at a valuable specialisation, you will quite likely advance against a weaker set of competitors. Deciding that you are stronger than, say, your Torpedo rivals is harder, although not so much now that they've been handed electrics.  If you are doing your fellows' homework, as opposed to the reverse, you have as good a chance as any other young man who has an uncle for an admiral. We'll strike that last part if you go for the Torpedo branch.

 Oh? Aviation? Hmm. Well, I can see that. You came of age during the war. You were bred up on the romance of the knights of the air, especially the ones who come in navy blue: BowhillCollishaw, DicksonBell-Davies, Longmore.

But here's the big roadblock. Fancy their fame? Too bad. You see, you were born in 1903. The war to end all wars ended before you were ready to end all wars yourself. Those knights of the air? You will never be one of them. Combat piloting is a young man's game, and there is almost exactly zero chance of a shooting war while you are young enough to fly the fleet planes of your generation. You will lust to get into a Nightjar,

and beat up fields or harbours or flight decks or launch rails, or whatever we end up using, on one of these

You'll be the "old man" of a squadron of these

 and you could lead your young men into battle in it. I do not think that likely, however. There will be another war. This peace is a weeping wound on the international body politic, but the nature of the wound will be to require a long half-healing before we are ready for war again. I will say twenty years, less two months, of course, so that the young men and horses can finish the harvest. As long as I am letting the past be the guide to my predictions, I will guess that the next war will go one year longer than the last, because men are getting madder in these latter days. In September of 1938, you will be 35 and a commander. In September of 1944, you will be a captain, looking for your flag. I hope for your sake that you will win your way through the mean trench fighting of postwar retrenchment to three more promotions, but I do not give you long odds.

So that's my cautionary. I'll leave it to this historian of the next century who has just popped by in his Collingwoodian time machine to give you some more solid retrospective insight.

Tuesday, October 22, 2013

First Parallel: A Technical Appendix: The Thermodynamics of High Altitude Air-to-Air Combat in the Propeller Age

The "funny" way of talking about the science of aeroengines --thermodynamics-- is to say that "you can't win, you can't break even, and you can't get out of the game." That's three laws, and I only propose to talk about one today: the Second Law. It is one of those hard-to-teach rules, and I am going to throw the "ideal heat engine" formulation up and call it a day: Efficiency=1-Temperature(reaction)/T(sink). The efficiency of the best possible heat engine is less than one hundred percent, and it is less than one hundred percent by the ratio of the temperature in the engine with that of the sink into which it is rejected. You think that engines are about power? I tell you that they are about rejecting waste heat. (Or, amateurs study brake effective horsepower. Professionals study calories rejected.)

If I wanted to turn the laws of thermodynamics into cod philosophy (call me, TV! I will!) then I'd call this the diminishing returns rule. Which reminds me.
Photoshop 1939! From Flight Global Archives for 2/2/39, the first official Air Ministry publicity still of the Boulton Paul Defiant. How many guns in the turret? Ha! We're not telling!

Flight, amplifying what the Air Ministry has to say, points out that sometimes official secrecy makes people nervous. "For the past year or two," the paper tells us, people have been writing in to ask what has been happening on the two-man fighter front. The Hawker Demon has been the RAF's frontline two seat fighter since 1930, and is overdue for replacement. Now, at last, the Air Ministry responds. The Defiant, we are told, is a stressed-skin fighter of all-metal, mainly light alloy construction (so much for the patent Boulton Paul construction system) with flush rivets for an exceptionally smooth surface. The feature of main interest is the compact, power-driven turret, armed with a still-undisclosed number of guns. It is presumed that the Defiant's main mode of use will be to fly slightly ahead of, and below enemy bombers, where they are typically ill-protected, as has been demonstrated by later-model "turret" Demons. Given, the paper speculates, equipment with a Merlin I engine, the Defiant will have a top speed of slightly above 300mph, lower than the Hurricane or Spitfire due to the encumbrance of the turret and because of its slightly larger size. Fitted with a Merlin II, it should be as fast as any comparable aircraft in enemy service, while with a Merline RM2SM, giving 1145hp at 16,500 feet when fuelled with 100 octane, it would have an even higher performance. The airscrew is a 3 bladed variable pitch de Havilland, and the exhaust is of the new ejector stub (i.e. turn your exhaust into rocket fuel) type.

But the point, now that I have buried the lede so thoroughly, is this:

It is October, 1943. The Home Front is bracing for defeat in the air, an ignominious retreat to night bombing that will delay the strategic air offensive by months. Meanwhile the United States Army Eighth Air Force is getting ready to win the most extraordinary victory in the history of air warfare. It will, flying from expeditionary air fields in the United Kingdom, win complete air superiority over the home skies of the world's second largest industrial economy before the first tide of summer.

Some people will say that it did not matter, that the only bombing that counts is the kind done in visual range of a foxhole. Some people apparently cannot wait to see the United States Army hump off its entire artillery arm on the USAF (or turn the USAF into the army's artillery replacement). Despite my frustration with them, I cannot say that they deserve to live in America whose only army is light infantry. No-one deserves to live in Breaking Bad America

The P-51 is said to have saved, by itself, the whole of America's industrial strategy. It is the classic example of Joel Mokyr's formulation of technology as a "free lunch," an exogenous input to the economic process, unpredictable and unplanned. One can only lay out a welcome mat on the doorstep, as meritocratic America and miltarist-racial Germany do, and class-ridden Britain does not. I have taken aim at the P-51's status as a magic aeroplane before, and yet its origins were almost entirely serendipitous. North American Aviation had established a relationship with the Air Ministry by selling it the Harvard, so when Sir Henry Self of the British Purchasing Commission approached it about licensing production of the P-40, company president Kindelburger was listened to when he proposed a new fighter, instead. A four gun machine using the Allison engine was proposed. The design was commissioned in March, 1940, and the prototype flew first on 26 October 1941. This is a short development period rather than an unprecedented one, and speaks, as much as anything, to the extent of underemployment in the Los Angeles basin in the spring of 1940. Yet it is also one of the most historically important of all successful rushed technological development programmes.

I have in the past featured the P-51 as a "magic aeroplane," basically as a means of launching into the transformation of the refining industry during World War II. As the cars of 2013 crawl through Vancouver's morning fog this morning, they are carried by the invisible tides of history. But no-one knows about them because they're invisible! Today I shall take another tack, all appropriately autumny, about how we're all trapped in a cellar while the entropic level rises around us ineluctably. 

Second year physics emo is so lame. In ten billion years, we'll all be dead! In your workplace, you might have noticed that a single missed shift has the potential to raise entropy to the eleventy-millionth power. Perhaps you have thought about the war, and imagined a bomb piercing the roof, and either said to yourself, "how could they possibly cope?" Or, alternatively, "How could it have made things worse?"

Or maybe you asked yourself how Erik could possibly have got from the Defiant to the P-51.

Monday, October 14, 2013

From Now On, No More Defeats: First Parallel

I'm mixing my metaphors. The artillerie du place opening up on the fortress from the first parallel is the opposite of the Charge of the Light Brigade. "Half a league, half a league, half a league onward." (Of many images available on the Net, I take this from a History of Surgery and Anaesthesia page.) Let's compromise on themes. Seventy years ago today, two groups (divisions in 1940s USAAF parlance) of B-17s raided the ball bearing plants of Schweinfurt, the swine ford, in Franconia. Fortresses charging.

It's a juxtaposition that works better with cavalry charges, anyway. Forts are (in our imaginations, anyway), the definition of far sighted, deliberate warmaking. Cavalry charges are the epitome of rash decisions. Blow the horn, and you're stuck with what comes next. If it comes home ugly, you are left to live with yourself. Even someone no worse than a cheerleader might get a little shrill as they try to find a way of blaming the other guy for fighting back. Since I am gesturing to Tennyson, here's Elizabeth Barrett-Browning, admittedly not talking about cavalry charges. (No, tell us how you really feel, Elizabeth.)   

I sense a guilty conscience, is what I am trying say, some way that it might be the universe's fault, that you did the best you could, that it had to happen that way. That's how you get 
 Weird, weird, weird, weird. Oh, and thanks to the Drifting Cowboy, by the way. And that's how I get to Schweinfurt: guilty consciences and thin rationalisations.

By the way, can I just say how awesome is is when there are still things on open shelves for browsing, such as the entire run of The Economist? Pull down a volume, and you can find out how, on 14th October, 1943, Seventy years ago today, 29 B-24s of 2nd Bomber Division, 8th Air Force, and 291 B-17s of 1st and 3rd Bomber Division set out from their British bases, to conduct a "Flying Fortress raid" on the important ball and roller-bearing plants of Kugel Fischer AG and Vereinigte Kugellagerfabriken AG, the large German subsidiary of the Swedish SKF. Photos show that at least half the facilities were destroyed, and Brigadier General Anderson of the USAAF suggests that the plants had been knocked out of production, and that a  restoration of 25% of production is the most that one could hope for in the immediate future. The Economist is not so sanguine. Ball bearings are a pretty quotidian product, and SKF's subsidiaries serve pretty much every national industry. Germany can import from Switzerland and France, as well as from Sweden.(The point of British attempts to tamper with the Swedish ball bearing industry are to keep the most valuable and difficult-to-manufacture types out of German hands.) The Economist does not know the numbers, but there are 524 American heavy bombers serviceable on the fields of Britain this day. It will later be established that there are 964 German single-engined fighters on charge within the borders of the Reich this day, although Richard G. Davis does not make it clear whether these are all serviceable, and I cannot check his source right now. (Hinsley, British Intelligence, III, 1, 296.)

A little further on in the same number of the legendary weekly newspaper for the economically-minded, editorial asks the question we long to hear answered in this October, when flame-red things flutter from the sky. "How is it that journey’s end may not yet be in sight even though most of the mileposts have been passed? Will the war be over in three months, in six, in twelve?" Do we not have threefold air superiority? Are we not bombing relentlessly? 

Monday, October 7, 2013

Postblogging 1939, Final Technical Appendix: The Problem of Control

It turns out that we did not, in fact, have a base on the dark side of the Moon by 9/9/1999. Even the idea seems a little crazy in 2013. But this is then, and Space 1999 was 1974, and people had a somewhat different idea about the likely rate of technological progress in 1974 than they do today. (Just to be upfront about that, I think that this perception is real, and has been explained by Ester Boserup, and would therefore like to nail my colours to the mast: the rate of technological innovation is slowing down.)

But opinions only go so far. How about a photoessay? It is 3 September 1939. This plane

was replaced by this plane,

which is still in frontline service.

It is supposed to be replaced by this plane, although in fact it will soldier on until 1942.

And the Beaufort will be replaced by 

In 1946. (Technically, the Brigand will replace a torpedo variant of the Beaufighter, the Beaufort having long since disappeared.)

The Hawker Horsley was the last all-wood plane designed by Sopwith-become-Hawker, entering service in 1926. The Brigand was a hasty development from 1942, and arguably the last prop-driven RAF strike aircraft to be developed. (We would be having the argument over the Shackleton, I think. Or maybe the Wyvern?) I've italicised the Brigand's vital stats. 

Crew: two, pilot and bombardier/gunner; 3
Length: 38 ft 10 in (11.83 m); 46 ft 5 in (14.2 m)
Wingspan: 56 ft 5¾ in (17.22 m); 72 ft 4 in (22.1 m)
Height: 13 ft 8 in (4.16 m); 16 ft 4 in (5 m)
Wing area: 693 ft² (64.38 m²); 718 ft² (66.7 m²)
Empty weight: 4,760 lb (2,164 kg); 27,500 lb (12,470 kg)
Loaded weight: 7,800 lb (3,545 kg); 38,200 lb (17,320 kg)
Powerplant: 1 × Rolls-Royce Condor III V-12, 650 hp (485 kW); 2 × Bristol Centaurus 57 radial piston engine, 2,165 hp (1,620 kW) each

Maximum speed: 125 mph at 6,000 ft (201 km/h at 1,829 m); 358 mph (576 km/h) at 13,700 ft (4,180 m)
Service ceiling: 14,000 ft (4,267 m); 26,000 ft (7,920 m)

Climb to 10,000 ft (3,045 m) : 14 minutes 20 seconds; 1,500 ft/min (460 m/min)


1 × forward-firing .303 Vickers;  4 x 20 mm Hispano Mk V cannon
1 × rear-mounted .303 Lewis; None.
1,500 lb (680 kg) bombload or 1 × [18"] torpedo; 1 22 in (559 mm) torpedo or 2,000 lb (907 kg) 

That is 20 years from deployment to deployment, but, put it another way, only 10 from the retirement of the Horsley to the specification for the Brigand. 

The bullet point summary could be that technological change, as measured by new generations of military aircraft, was a lot faster in the 1930 and 1940s than it is today.  But I do not think that this summary point is a very helpful one. I certainly would not advance it as an illustration of my Boserupian claim that technological development is a function of population increase, because I have not established that the jump from (say) the F-15 to the F-35 is comparable to that from the Horsley to the Brigand. More likely, it illustrates the harvesting of low-hanging fruit.

I'm reaching for something deeper.