Monday, August 11, 2014

Postblogging Technology, 1944: A Technical Appendix for July 1944: Making the World Safe for B-29s

A bit of an amuse-bouche here. This is Highway 19, completed in 1979 between Campbell River, British Columbia and Port McNeill, in the same province.

This is not what it looks like on the ground, because Google fails me, or people are reluctant for some reason to put up pictures that show that the roads to their town are awful or little used. Fortunately, the residents of the old Canadian Forces Station, Holberg, have a certain perverse pride in the tradition: here's Elephant Crossing:

It was not, by a very long shot, the worst stretch of road in northern Vancouver Island in 1979, nor today, either. There are many fewer now, though, because we have got a great deal better at building good, cheap roads. This is why I think it is time to look at the B-29, seventy years after the summer in which Hobo Queen toured Britain, intending to give the Germans the impression that Twentieth Air Force might fly against them as well as against Japan.

Now, some readers may have travelled Highway 19 as an Officially Scenic Tourist-Type Route, on their way to catch the Inside Passage ferry that runs from Port Hardy to Prince Rupert. (If you have, locals are grateful but somewhat uncomprehending, at least if they're old enough to remember the Nimpkish, see below.)

Campbell River has some slight fame as the town where Hollywood stars used to come for ocean salmon fishing, back in the day when this was something that stars did. Nowadays it is a sleepy town of 31,000 which is notable to me mainly for doing a wonderful job of raising three nephews and a niece. Port McNeill, where I attended high school, is a town of 2500.

I have intimated that the region is not exactly populous before. The regional district of Mount Waddington lists a 2006 census population of 11,600. In my day, the usual off-the-cuff estimate was 10,000, with the steady shrinkage of outlying communities made up by the steady, tourist-related growth of Port Hardy. What I have not suggested, because of the gap in experience, is just how empty is a landscape of 20,000 square kilometers occupied by less than 12,000 people. In the rest of the world, a town is a sensible thickening of population as you drive through a landscape of houses, fields and strip mall. Port Hardy and Port McNeill as a little like that, but the rest of the towns in this region might as well be holdfasts in the forest, surrounded by walls that keep the rampaging orcs out.

Pictures to Drive the Point Home

This is a washout on the new road, somewhere south of Woss, where the highway climbs through the folded mountain range that had defied earlier efforts to open the north island since long before "the coming of the white man," as they used to say. (In fact, whalers and traders have been wintering over at Winter Harbour since approximately 1805, so there is obviously a long and rich history of "Whites" in this region. The real reason that we put the "coming of the White Man" so late is that we really don't want to talk about those details, and are just as pleased that no-one will ever write A History of Winter Harbour, leaving matters instead to Franz Boas's well intended and not-as-naive-as-it-sometimes-seems romanticism.)

Anyway, digression over, Washout on.

Geologically, the road conquers a difficult upland here. Engineering-wise, you can see that the BC Highways team was pretty good at putting solid roads through uninhabited regions by the mid-1970s. Here, by contrast, is a roadcam capture from a section of Highway 19 dating to some point earlier date. I am guessing that this is a stretch on the way to the farming community of Sayward in the Salmon River Valley, just south of the Kelsey Bay.

The older sections of Highway 19 will bow to no road in the First World for honours due to engineering primitiveness. There are sections, all now thankfully bypassed, where in the early 1990s people still backed out of their driveways onto a main trunk road. This was because the road was originally threaded through existing communities on the cheap before World War II, but the section above, if I am right about its location, was built in the late 1950s to connect the ferry wharf at Kelsey Bay with Beaver Cove south of Port McNeill. Here is that "link in the provincial highway system," as our then Free! Enterprise! provincial government characterised it when it took over the private Black Ball Line in 1960.

Although I suspect that the picture itself is from the early 1970s. It is from an incredible site run by "Darkroom Dan Propp" and posting, amongst other images, pictures from his published postcards.

Two takeaways here: the awful road in the roadside cam shot above is probably a half hour's drive from the brilliantly engineered one in the first. Yet they are separated by a little less than thirty years of progress. Second, in the early 1970s, when outdoor recreation still meant getting away for some fishing and hunting, the ferry dock at Kelsey Bay could be a pretty happening place, as you can see. Yet the provincial government thought it more economical to build the roads between Campbell River and Kelsey Bay, and between Beaver Cove and Port McNeill, and run a ferry between them, than to throw an "all weather paved road" over the low mountains between the Salmon and Nimpkish valleys. That's the Nimpkish, by the way, a stretched vessel with a unhurried five knot pace that made the trip in six hours. That's a long trip when you're seven. A very long trip.

Why? Well, progress, obviously. We got a helluva lot better at building roads in the mid-century. My thesis (stop me if you've heard this one!) is that much of that porgress happened during World War II. It just took a while to percolate down through the system to outlying places like northern Vancouver Island.

This is the summer when, in the midst of much else happening, the Allies found time to drop some hints that the B-29 might be fielded against Germany as well as Japan. That did not happen, but the engineering for it did at least begin. By which I mean that the world is being made safe for the B-29. Hobo Queen has been flown around Britain, satisfactorily demonstrating what a civil engineer would not have doubted, that existing airfields will not support this machine, with its 141,000+ all up load. RAF Marham, twelve miles from King's Lynn in Norfolk, square in the Great Fens, has been closed for the building of  "Cass AA" runways. In the wake of the immortal moment when the first and only Douglas B-19 was rolled out of its hangar and onto the tarmac, only to have its tyres break right through the asphalt and settle, immovably deep, in the soil beneath, aviation engineers have been alert to the issues of soil load.

Here is the B-19 with its undercarriage above ground.

Now here is a closeup of the double-tyred Heinkel He 177 undercarriage:

That is an awful lot of apparatus to retract into a wing that is supposed to lift a plane! It is n wonder that the He 177 had so much problems with the "flying" part of its mission, and one supposes that the undercarriage might have come in for a bit of a look had they ever sorted out the "engines catching fire in mid-air thing," upon which matter the crews tended to focus with an intensity that an experimentally-minded mechanical engineer could not fail to find disconcerting.

"These cowboys have no appreciation of how hard we at Heinkel are working on the "not catching fire thing." It is one of  our two number one priorities! Along with horsepower and fuel economy. I'll come in again."
The issue of soil-loading under an appropriate pavement is not a trivial one. John James, in his Paladins, has made a valiant effort to tell the story of the expansion of the RAF in terms of infrastructure. While not always correct in detail, he is perfectly right to point us to a story basically told in terms of an evolution from grass strips to concrete hards. A well-tended British pasture is actually a pretty solid pice of ground, but in the six war years, four hundred and forty-four airfields were built for the RAF in the United Kingdom, with paved runways, perimeter tracks and hard stands provided at a total cost of 200 million pounds, a peak labour force of 60,000 in 1942 (11,000 in 1944), and requiring the laying of 175 million square yards of concrete, tarmacadam or "other handy surfacing material." (Mostly stone bound with asphalt.) This corresponded to 6.5 million tons of concrete and 45 million tons of sand, ballast and crushed stone. In 1939, only nine airfields had runways, with a maximum dimension of 1000x500 yards, designed to take the heaviest aircraft then in service, the Wellington, at 32,000lb all up and 45lb/square inch tire pressures, the existing standard for auto roads. The B-29 was 140,000lb at 85lb/square inch, and what I had not noticed in previous readings of Hudson* is that the "Class AA" he describes in this 1946 paper as under construction in 1945 is actually for the still-secret B-36, at 360,000lb all up, tire pressure 120 lb/square inch.  

In 1939, it is hard to emphasise enough that airfield construction was a derivative of "land improvement." The improving English landlord had been subsoiling, draining, cultivating turf, liming, fertilising and manuring, and working the soil with ploughs, rollers and harrows in preparation for taking off both traditional hay and novel fodders such as "compressed grass." The RAF would be that business in the 1930s, profits from sale of mowed fodder being a significant item in the Air Estimates. (By significant I mean covering less than 1% of the Air Force's budget, IIRC, but better than nothing!)

As Hudson notes, in some ways flight safety was the initial driving factor in airfield development. Before permanent runways thrust themselves into engineer's consciousness, aircrew interest in surviving bad takeoffs and landings led to pressure to clear the immediate area of low obstacles and to extend the landing on/off surface, in all directions to reduce the need for landing off the wind direction. (Aeroplanes are supposed to land on their wheels, not their cockpits.)

At a typical station (evidently flying American types), by 1945, the original 950 yard meadow had been replaced by 10000 yards of hard surface for the Wellington already, and then by stages to 2000 yards of concrete to accommodate a plane with an auw of 67,000lbs and an American-style high pressure tyre of 85lbs/square inch. To accomplish this, some 50,000 cubic yards had to be excavated, on average, and all of that concrete laid.

Notice that all of this was done in a tearing hurry. A new runway was demanded, construction details were set, and the Soil Laboratory had as much time to get the science right as there was between letting the contract and beginning work. Professor Harold Westergaard, fresh from the Hoover Dam by way of Harvard, had a theory about how unreinforced concrete slabs would interact with subsoils, some math was done, and people began to pour. Slabs rose from 5" thickness in 1942 to fully 12" in 1945. this is a pretty big piece of concrete to expect to just settle and give homogenous resistance aiming for 6000lb/square inch, and design is a surprisingly complicated matter, going far beyond just cyclopean scales of pouring. When you roll over the bump at the long, lateral crack across the road at the beginning of the bridge or viaduct on your route, you are running across one of Professor Westergaard's expansion or contraction joints, and the fact that the bridge does not collapse beneath you proves that either he was right, or that we've refined the theory since. Without Westergaard, there would be no B-29.

As should be clear, vast amounts of American "earthmoving plant" was required to accomplish this. By 1944, the Ministry had 360 tracked bulldozers and tractors, 215 excavators, 34 scrapers, 20 graders, 24 front-end loaders (not yet conceived as a distinct piece of machinery, but described as "ditchers and trenchers"), 406 rollers, 5300 dump trucks, 227 spreaders, and 500 compressors.

That this counts as a "vast" earthmoving plant in 1945 is telling. And while we nod in appreciation of the historical cliche, Hudson inadvertently contrives to illustrate just how primitive the ultra-modern technology of roadbuilding was at the white hot centre of innovation that was the struggle to make the world safe for the B-29:

This posting has, you will notice, been, in substantive terms very little more than an exercise in nostalgia yoked to a long-delayed summary of the Hudson paper. There is a reason for that. Paving is hugely uninteresting, even though I bet that if you were to walk your neighbourhood, you would be able to write a new history of it in the age of the concrete on the sidewalk outside. It is the kind of history that escapes human attention, just there, presenting a loadbearing face uncurated by our stories. 

By this I have in mind the way that Winter Harbour's history escapes our attention because we do not want to think about it, and also the postwar expansion of our roadnet. If we think of that expansion void of human agency, as a visible manifestation of the advance of technology, or, less benevolently, of "car culture," some kind of cultural shift towards everyone living a long way from where they work and driving the intervening distance because that way Detroit makes more money, then we are at risk of not noticing the human changes wrought by World War II. 

We live in a paved world. I was going to end this with a brief photoessay on "sidewallks on my block," but my iCrap is refusing to cooperate again, and, anyway, I should probably spend more than five minutes on the project if I intend to curate a usable collection of sidewalk pictures. 

It's a paved world; it's a changed world. We are free on the land, because of World War II.

*Philip Gordon Hudson, "The Development and Construction of Airfields and Runways for the Royal Air Force, 1939--1945," The Civil Engineer in War, 1: 4--48 (London: Institution of Civil Engineers, 1948, 3 vols.)

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