Thursday, January 3, 2019

A Technological Appendix to Postblogging Technology, October 1948, I and II: Prestressed Concrete

You know the story: The world is without form, water fills the void; Pregnant girl falls from the sky; Turtle saves her by bearing her on her back; Muskrat dives to the bottom and brings up mud to build an island on top of Turtle's back; Girl gives birth to the ancestor[s] of the human race. I think this is the story behind James Fenimore Cooper's The Deerslayer, but the important point is that the picture is of Rita Moreno playing Hetty Hutter, and carrying Killdeer, the American Excalibur.

The moral of the story is that Rita Moreno was a very attractive woman in her time; and also that I need to talk about rafts underneath the world. Really! This isn't my obsession with James Fenimore Cooper! It's an important bit of the history of technology that I have inadvertently exposed to the light in the last month of postblogging, and I'm actually quite excited about it because it might shed some light on something that I've been wondering about on my commute, ever since I began doing the part in Vancouver on  a bike in 2014.


Ahem. For the last almost-five years, I've been commuting up the Valley Route (not the Central Valley Greenway), which is a north-south alternate bike route through the west side of Vancouver (as distinct from the West End and West Vancouver, we have a lot of "wests" around here.) The Valley Route is named for Valley Drive, a strange, but conveniently wide and little trafficked street that takes off from one of Vancouver's old east-west processional ways (25th, King Edward Avenue, if anyone cares) at about 30 degrees to the main grid, turns left at a "T" intersection facing a satellite campus of Prince of Wales High School, then dipsy-doodles around to cross Arbutus (I think it changes its name and then changes back) at the foot of a bugger of a hill up onto the plateau that makes up midtown Vancouver, upon which is located my current workplace.
Wide streets, broad shoulders, no fences, big houses. The trees are also a giveaway of recent construction. The streets that surround this little enclave follow the traditional grid and would give your average rain forest a run for its money on the canopy front. 
It is a very strange part of the city, but also not very scenic, so I have never heard it explained to me, but it is squeezed in between ridge lines on three sides, and the wide lots and uniformly newer homes strongly suggests to me that it is reclaimed wetland first built over in the late 1960s or 1970s. I do not claim to be an expert on developments in the field of building-houses-in-swamps in the last fifty years or so, but this month's discussion of soil engineering in The Engineer suggests what might have changed in that timeframe.

I didn't realise this until I went to take these pictures, but there's a very slight hump in the road that blocks the view forward from the first location. Once over it, you can see a full seven blocks down to Prince of Wales' (lower) field. It's a very farm-country view for Vancouver. If anyone is wondering, by the way, the pictures were taken at about 2:20 in the afternoon. If anyone has ever suggested to you that Vancouver can be a bit gloomy in the winter, believe them!
Civil engineers in the Netherlands have long found that their wet and boggy soil requires some kind of substrate rafts before they could build solid structures. As we learned from the continuing sessions of the World Congress on Soil Mechanics, those structures included the runways at Schiphol Airport, near Amsterdam. 

In 1948, we're basically in the middle of giving up on sacrificing aircraft performance to runway bearing limits. It's soon going to be over to the civil engineers to find a way to make the world bear up under what the aerodynamicist imposes. We live in a profoundly transformed world because the civil engineer found a way of making those rafts. And we know squat all about it.

By Michael Schmahl - Own work, CC BY-SA 3.0,

The magic solution, it turns out, is something called prestressed concrete. It comes up in the papers given at the Conference repeatedly, but, unfortunately, no-one hired a trumpet player to perform a triumphant air every time the phrase came up, so it is easy to miss the revolutionary character of the new material, which is essentially concrete which has been placed in a cradle of steel cables and put under tension until it is packed down and strong, allowing you to make longer pieces, whether beams for bridges or rafts for pavements. Usually cast in forms and then moved to the site, it has a somewhat obscure history. The Designing Buildings Wiki attributes the invention and the patent to, as usual, an obscure American, in this case San Francisco engineer P. H. Jackson, who patented pre-stressed concrete in 1886.

No-one else knows anything about this, and, as is often the case, it turns out that Jackson was copying or developing Joseph Monier's French patents for reinforced concrete, which contained elements of the later prestressed concrete concept. Actual construction in prestressed concrete had to wait until the 1930s, and another French engineer, Eugene Freyssinet, who worked in prefabricated reinforced concrete structures between the wars, and discovered that he needed to accommodate creep and relaxation, which can be done by first prestressing the beams. Marrey and Grope characterise Freyssinet as being somewhat desperate to find new uses for his techniques after a technical tour-de-force rescuing the Quai d'Atlantique at Le Havre from subsidence in 1935. Whether or not this was the case, he found work building bunkers for the Germans in the last years before the war. Reinforced concrete had by then been in general use in fortification work in Europe for a  half-century. Prestressed concrete opened up (limited) new vistas, and given the general confidential nature of fortress design, we perhaps know less than we could about the extension of prestressed concrete work in the 1930s. 

We do know, however, that German engineer Karl Mautner worked with Freycinet, crossed the Nazis by accidentally being born Jewish, and left the country for Britain in 1939, where he became associated with the Mouchel Group.

By David Ashcroft, CC BY-SA 2.0,
  In a nation at war, prestressed concrete soon found numerous uses of which the above, the Adams Viaduct, is the first railway bridge made of prestressed concrete, so quite revolutionary in spite of being so aggressively mundane in appearance. This is, in fact, something of a general problem with prestressed concrete construction. As impressive as the buildings are, they have a tendency to be functional and  boring. For example, to continue on the aviation theme, giant hangars for giant airplanes were an early application. 

(Scraped from Marrey and Jupe [pdf].) 
Although, to be fair, The Sydney Opera House and CN Tower are also built of prestressed concrete. Aside from railway structures, hangars, parkades, massive old Vancouver shopping malls with rooftop parking, and a few iconic pieces of modern public architecture, perhaps the most important application of prestressed concrete is thoroughly invisible: the raft slab.

CC BY 2.5,
There is not necessarily a raft slab underneath your house, but it is a common solution to erecting homes on non-bearing soils. As of this moment, they are the last word in liberating humanity from the constraints the Earth would like to impose on us. They are the firmament on which our modern, technological world is founded. And while this started with an inquiry into the oddly atypical homes built along a seven block stretch of road in Vancouver, prestressed concrete is probably going to turn out to be fairly important for building Interstates, and I think the reader will concede that those are a big deal, too.

. . . 

This is not quite enough for me, so I am going to launch onto something that isn't quite a digression. Killdeer's association with Turtle Island might or might not go beyond James Fenimore Cooper, but let's go with Cooper. He invented the superhero, so let's give him credit as a founder of our modern world. Of course, he was wrong about one thing. For Cooper, the hunting rifle was an elite weapon, clearly distinguished from the smoothbore blunderbuss with which Judge Temple ineptly hunts. The next century would go far to prove Cooper wrong, as the rifle emerged as the weapon of the industrial nation in arms. Which brings me to. . . 

Something that has come up around here before, the EM-2, sometimes Janson Rifle or even the Mamba. 

Here it is, being shown to the world in 1951. 

The story is reasonably well-known in firearms circles. In the course of WWII, British firearm practice reached peak absurdity after fifty years of bungling procurement. The standard long arm, the Lee-Enfield, fired a ludicrously outdated rimfire 0.303 round that had been slated for replacement before the last war. The "battle rifle" concept was similarly obsolescent by the outbreak of WWI, although this had not been recognised, which is why the intended British and French replacements to the Lee Enfield and Lebel fizzled out. Like every other WWII army, Commonwealth forces supplemented their battle rifles with handier submachine guns, which had the minor disadvantage of being all but useless in many situations. Meanwhile, the Royal Armoured Corps had somehow been allowed to go their own way and adopt their own modern rifle calibre weapon, the Czech-designed Besa machine gun. So hurrah for the old ordnance specialists of the K.u.K. Armee! (Handy link to the Radetzky March for those as want it.) 

Meanwhile, in Germany, various people had been broken out of the old rut by a desperate lack of battle rifles, the long barrels requiring a bit more machining than a national industry on the edge could provide. "Nazi supermen are our superior" narratives rarely help us move discussions of history of technology forward, but they are not always wrong, and the Germans did come up with the 7.92mmx33 Kurz round to give a lower-power cartridge that could be fired in full automatic mode from the shoulder. That being said, the French might be said to have blazed a trail by cutting the cartridge of the MAS-36 rifle down to 7.5x54 from 7.5x57 in the Chatellerault light machine gun. It isn't much, but accepting non-compatibility between rifle and LMG is a pretty clear recognition that something has gone wrong. 

In any case, the British response is quite clearly distinct from the German, since all the British postwar small arms experiments start with the cartridge, and the "British .280," a 7mmx43, is, conceptually, its own thing. I yield to the narrator of British Pathe, who identifies its main advantages as being a high rate of fire in semi-automatic, aimed mode, combined with light weight and handiness. The bullpup design, which might or might not have been a good idea, had a great deal to do with this, but it comes down to the British Army wanting a rifle that weighed 3.49kg at 889mm length, vice 3.96kg and 1132mm in the lightest version of the Lee-Enfield, or the 3.79kg, 1080mm to which the FN FAL that actually replaced the Lee Enfield was eventually brought by ordnance engineers. The whole story there is somewhat dispiriting, in that the Americans were able to scuttle the EM-2 design on the pretext of imposing a more powerful battle rifle cartridge on NATO, and then defected from their own ergonomically unsustainable triumph by adopting the 5.56mmx45 cartridge in the M-16.  It having been belatedly noted that this calibre, while fine for urban combat AND KILLING ROOMS FULL OF KIDS NOT THAT ANYONE CARES ABOUT THAT, is a bit of a stretch in open, mountainous terrain, something that the inventors of the battle rifle of a century past could have told them in the first place.

So what's my point? That I couldn't wait until 1951, when this hits the news, to discuss it? Well, yes. But! I am also returning to the idea that the rifle is one of the instruments with which the modern state interacts with the landscape; and, importantly, the way in which it (used to) do so that required the participation of  the masses in an existential crisis for the state. That last participation, adventures in North Africa, Italy and Burma aside, was above all fighting for acres of mud in the Netherlands. Here is the British Army blowing up some earthworks in the Netherlands.

See? Cutting 20cm and 500 grams off the shoulder arm matters when you're being carried around the battlefield in LVTs and APCs, and then scrambling around in this crap.

Okay, I'm struggling a bit. Put it another way. Atlee's army is trying to give conscripts the tools they needs to win WWII if it happens again, only better this time. 

For example, the Bren Gun Carriers are going to be much more posh. It's a commuting army, and that means more room to store the bumbershoots. (Brits say "bumbershoot," right?) 

I say it's no coincidence that Churchill's incoming government scuttled the EM-2. Universal service would follow soon enough, and while God knows I'm not nostalgic for it, I'm not exactly pleased by the way that the neoliberal citizens-as-liabilities social order has worked out, either. It's a new world, a built world, and fifty years after WWII, a lost innovation of 1951 is probably the best rifle for a levee en masse to fight in it. God help us if we need the EM-2 to fight a modern war of national mobilisation: point is, we have a test of just how far we have not been tested as a first world society since WWII. 

1 comment:

  1. You might want to check out which is Ian McCollum's "Forgotten Weapons" disassembly and history video on the EM-2.

    Rifles were militarily dominant from 1860 to 1914; after that it's artillery and the ability to industrially mobilize. (From 1970 or so, mass anything matters less and less.) The post-War intermediate cartridge ideas in Europe were strongly logistical; the original FAL was in that same .280 cartridge, it wasn't just the UK that had agreed on it. The US didn't accept them because the US Bureau of Ordnance is heavily culturally corrupted by target shooting scores and makes terrible rifle buying decisions in consequence more or less throughout its history. Which is why we got 7.62mm NATO because it more or less mimics the ballistic performance of 30-06 in a shorter case; the 600 yard target scores aren't affected, and that was really, really important to the US Army.