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. 

The point here is that the Air Staff, sitting around the table on a given day in the spring of 1939, lived in a world where the disappearance of the Horsley was as recent as the 2010 midterm elections in the United States, and the introduction of the iPhone4. The specification of the Brigand was as close to them as the 2016 Presidential election, and closer to them than the iPhone6S. It is the fluidity of technological change that I feel compelled to point out. 

In writing about technological change in the spring of 1939, I think that I can safely single out three themes that were vital to contemporaries:

i) The rapid development of variable pitch airscrews;
ii) The problem of ground control of aircraft flying in nonvisual conditions;
iii) The development of flaps and slats to vary wing geometry.

Three other developments of enormous moment get less frequent mention, in spite of their importance:

2.i) The rapid development of light alloy structures;
2.ii) The development of feedback-controlled carburetors;
2.iii) The development of two-speed and two-stage engine-driven superchargers.

Overhanging them is the Big Secret that cannot be spoken in Britain, although it is a commonplace in the United States:

3) The introduction of 100 octane fuels. 

You will notice that not all of these seem equal. In particular, 2.ii is a bit fiddly. The Dowty Live-Line Pump, "the Carburetor that Thinks For Itself," certainly proved itself in World War II, but does it really belong in the same position as the other options? Contemporaries even denied its importance entirely (as British Airways did in a Flight article on their maintenance procedures), or argued that exhaust gas analysers were a better control tool. Clearly, it impresses me because of the clearly-signalled "information technology" aspects of the device. Am I not, with perfect hindsight,looking backwards to the signs of an imminent IT revolution?

Why yes, I am, but I am doing so for a reason. I was in our local second-rate academic library the other night, and, after some cutting edge reading, moved on to scan the shelves in the venerable D,700--800 range. There, once again,  between the Holocaust and spy stuff, was the catalogue-reified Great Technological Secret of World War II: radar. The books there, at least in the University of British Columbia;s Koerner Library, seem crowded, a little defensive. There is always room for another book to either side, but here in this short shelf, Guerlac and Brown have been joined, none too recently, by an extension of the RCAF official history.

I understand why this is. In a way, the story of Canadians and radar encapsulates it. The sleepy dominion received the news of radar as something of a bombshell, and launched parallel programmes to build a domestic radar and to train radar technicians for the war effort. Then all of that effort went out to expand the radio business, create a domestic TV industry, and, from there ever onwards to phones that run out of juice while  automatically downloading upgrades to games you've never actually played. 

I assume that Canada saw an effort to build live-line carburetors, or at least to train technicians to service them. No-one hears about that, and no-one cares. It happens that in the summer of 1945, a mathematician named John von Neumann circulated 

this, and everyone realised that they were working on "computers." The idea was perhaps a bit obscure as illustrated, but it was subsequently explained that the bit inside the box was basically like a brain, and that was that. 

It was a box that thought for itself. That this metaphor was about as useful for describing undercarriages that descend at the same speed on both sides of a plane as it is for describing .... No, strike that. It's far more useful for describing two wheels that automatically correct each other's rate of descent than it is for describing minds. Fortunately, it is very useful for describing undercarriages, and the only people who get hurt by the brain-as-computer metaphor are some philosophers of mind. (With neuroscientists and linguists as collateral damage.) 

But come back to 1.ii for a moment. Last time I was trying this wrap-up business, I inveighed against the idea that the RAF was somehow institutionally blind to the problem of bomber navigation. In fact, I said, any familiarity with the actual progress of technology at the time would reveal the centrality of the problem, and, indeed, so would common sense. 

So how, then, did British bombers come to find themselves groping blindly over a nighttime Reich? Well, the short answer is that their designers did not anticipate that France, Belgium and the Netherlands would be defeated and occupied by Germany, which Britain would then decide to fight by means of an extended, attritional strategic bombing campaign. 

The long answer comes back to "QBI," radar and control, and the inextricable interconnectedness of technological development. 

In the high summer of 1939, a pilot, say, of a civilian airliner trying to find his way accurately from Sydney to Auckland, or from Paris to Berlin, faced a neat set of problems if he had to ask  himself, "Where am I?"

Possible answers:

1. i) We can look down. But aircraft are faster and more fuel efficient at higher altitudes. It has thus become dramatically harder to see the ground at a given moment than it was five years ago. We're higher up, and will be getting higher as supercharging develops.

ii) We can look up. Fortunately, aircraft have recently grown observatory windows of lightweight aeronautical grade  optical plastics. Unfortunately, this compensated for closed cockpits. It is harder to look up than it used to be. Also, the plane is going much faster. Fixes are more demanding to take, and less accurate. As progress on superchargers and airscrews continue, planes will continue to get faster.

iii) We can track our previous progress by "dead reckoning." But speed is increasing, and so is distance travelled. And we are, in the end, at the mercy of both the instruments that measure our airspeed and of the meteorological report that gives wind speed and direction --at elevation. I join in general abuse of the em-dash here to emphasise the recursive nature of this dependence, by the way. Barometer readings are necessary to correct the airspeed reading from the pitot, which in turn will depend on altitude readings, which will need to be corrected by a reference barometric reading that has to be accurate for our current location.

iv) And that is even without taking into account the problem of bearing! The compasses and gyrocompasses (both necessary because of north deviation) with which the reader will be familiar have an annoying habit of swinging their needles about. This is a side-effect of free indication. There is no exact solution for oscillation in a free indicator system. Damping, which I gather is done in magnetic compasses sometimes, is critical for the use of gyroscopes in any stable system. But it has to be accurately computed.

v) This is a lot to think about. Ideally, we would want to automate as much of this process as possible, and, as I have already noticed, this was actually accomplished with the Air Speed Indicator, from 1943 and the Ploesti Raids . Here is another technology that raises the spectre of the problem of control and points us towards our computing future. Too bad that I can find no-one actually promising an ASI in 1939. It seems likely that it would have been an after-factory addition to the B/1/39 and probably the Bristol Brigand.

vi) We can look at random radio signals. Here we get the Direction Finding Loop, such a prominent feature on the typical sideview illustration of a World War II warbird. All very well if someone is broadcasting, but only as accurate as the antenna.  The Horsley's dedicated W/T Operator had to know Morse, and was busy in the last minutes before landing  spooling up a trailing wire antenna with a crank. It had to be meters long to pick up short wave transmissions, and, if left hangind, would tangle in the undercarriage. The Brigand's pilot could talk to ground control, the other planes in the formation, and crewmembers by pressing the right buttons in front of him. The reason for the change is not that they only invented the higher frequencies of the electromagnetic spectrum in 1942. It is that antenna design is hard. "I wish I had an electronic brain for all of this arithmetic" hard. And then there's the problem of putting a suppressive harness on the spark plug. Would it surprise anyone if I said that this was getting harder as engines got more powerful? (There is, I think,  a complication that goes to engine control, mainly having to do with advancing and retarding engine timing, but I'm going on an idle memory here.)

So with all this taken into account, it is no wonder that we move on to 

2): Asking people on the ground. After all, we've already accepted that we're going to have to ask them what the weather is like!

So the basic problem here has now become one of radio range. Given that we are in range, we have two options. 

So, to retain systematisation, 2.i) Asking people who are available to take our calls, or asking an automatic answering machine. One is pretty simple, and developed early. We politely ask, "Where are we?" And people on the ground, with plenty of time and plenty of space to spread out their charts and protractors, and great big Adcock arrays that do not have to be loaded up with precisely calculated resistances to work, will zero in on your emission and tell you where you are. Quite possibly, tell you with enough accuracy that you'll be able to descend right through the low-lying fog and land at a commercial airport. 

Or, if it is wartime, and you are in a Whitley over the Rhineland, the French Air Force will politely tell you where Krupp is from your current location. Of course, you will also then have told the German Air Force where you are, which may or may not be acceptable. 

So, 2.ii) The automatic answering machine option, otherwise known as "riding the beam." A German fellow named Lorentz (a different Lorentz, and the source of endless hilarity in my graduate student days) has been working on a beam-following system since the 1920s. It is in Lufthansa planes, and, it will turn out over Coventry, in their military counterparts, too. The Royal Aircraft Establishment doesn't like the Lorentz system. It wants something that will give "glide path" guidance, that is, will give a series of distances from the destination as well as a directional bearing. This is something of a Holy Grail for beam-finding systems, mainly because, while not technically challenging taken in isolation, it greatly restricts the range of a beam-riding system. And, unfortunately, no-one is around to tell radio waves to stop propagating when they stop being useful. There are some funny stories from the United States about what happens when a pilot latches onto a radio beam out at that kind of range, which, with night effects, can itself vary wildly. And by "funny" I mean in the sense that "lithobraking is only funny when it happens to someone else" funny. So before you want to trust a radio beam for guidance, you might want to ask yourself how far you are from it, and, because this is an optical distance thing, how high you are. 

There's also the thing that broadcasting a radio beam is not necessarily a good idea, militarily speaking. The Germans could do it because Bomber Command was only going to back track and blow up occupied France and Belgium. Serve them right for not shaving their arm pits and suchlike Gallo-Belgian peculiarities! Bomber Command eventually opted for this course, doing its part to develop LORAN, which went from being the most important navigational advance ever to a quaint antiquity without ever attracting a historian to explain what made it so important. 

Oh, well, maybe later. The point is that the problem of control and automation is immanent across the whole range of problems that the Air Staff is trying to untangle so as to push forward with the basic exercise of BOMBING GERMANY FOR GREAT JUSTICE!!1! It just doesn't realise it. The metaphor that could guide it has been invented, by George Dowty no less. (Just kidding. Obviously George Dowty did not invent the machine-that-does-something-is-actually-a-brain metaphor. That'd be the Enlightenment guy with the alleged chess-playing automaton, or maybe Raymond Llull, or whoever else we are pleased to argue for in the Annals of the History of Computing these days. I have to admit that I haven't checked recently. (Notice that Llull is such an innovator that in the woodcut he has even invented smoking! Or possibly speech balloons. Either way, I hope he patented it.)

This is not to say that the Air Staff ought to have realised that it was groping its way towards the computer and cancelled the Avro Manchester to shift resources over to iPad development. It is that it is the middle of the technological process, unable to see to the end, able only to fail forward towards unguessed outcomes.

And this is what an era of actual rapid technological progress looks like: sprawling lines of intersecting development, cascading genealogies of failed-forward machines leading to an unguessable future, retrospectively colonised by patent trolls whose main contribution to the process is to retrospectively make it look like it is simple and that only idiots and the self-interested could have failed to see it.

And now a message from the fine people at Struthers-Dunn. 

It's not every ad buy from the fall of 1943 that is still paying off!


  1. The museum I volunteer at (except when it is closed due to government incompetence) has just opened a new gallery- Time and Navigation- drawing explicit links between marine navigation, the longitude problem, etc., air navigation in the 1930's and 1940's (with a full display on LORAN), and then both kinds of satellite navigation (getting probes to other planets and getting around town thanks to your GPS). Really fascinating stuff.

  2. It is. The period after 1945 is really a golden age of navigation. Airliners full of Very Important People were making transoceanic flights and transpolar flights only twenty years after the "Ares" proving flight was up there basically to fly a bay of prototype compasses over the magnetic north pole and see what happened to the various designs. ("magnetic flux gate compass" is the only specific design label I remember off hand.).

    And yet by 1965 the biggest concern was whether the "stewardesses" might be too sexy. Too sexy by far....

  3. This comment has been removed by the author.