Sunday, August 18, 2013

How Can a Flat Bridge Be "Extradosed"?

The bridge over the Quinnipiac River may be more expensive  and less efficient than necessary.

This is certainly not my opinion because I am not an engineer or bridge designer.  This is the stated stand of the Structural Engineering Forum of India.

Before we get into that, what exactly is an "extradosed" bridge? Just because the state Department of Transportation calls the structure that in press releases, does not excuse publications that print the press releases from explaining.

To summarize, extradose is the outside measure of an arch. The inside curve is called, what else, the "intradose." Architecture is filled with esoteric names for things. Know what "ogee" means?

Architecturally, a Gothic arch with a peak is made out of two ogees. (right)

 "Ogive" describes the  shape of the nose of a rocket or a bullet. (below)


 There are dozens of words for different curves. The Sears-Hack Body, for instance, is a an aerodynamic shape that produces the least drag.

If you're sitting around with nothing to do, search "names of curves" on Google. 

Now, the bridge over the Quinnipiac does not seem to have much extradose, or extrados.

Extradose and iontradose
 In fact, it is a cable-stayed extradosed design. This looks superficially like a suspension bridge, but is fundamentally and physically different.

Suspension bridges use much larger towers to carry a thick "caternary" of cable. Smaller cables connected to the large one are connected to the bridge deck, holding it up. 

A cable-stayed bridge uses cables from shorter towers to connect directly to the bridge deck.  The cables also perform different work. Since they meet the deck at a low angle, they tend to add to the longitudinal strength of the bridge. 

Cable-stayed extradosed bridges have a box-girder bridge deck, but are thinner than  plain box-girder construction as typified by the old  Q bridge that is now being torn down.

The idea of cable-staying a bridge dates to the 19th century. Now cable-stayed exterdosed bridges are used because they require shorter towers, have less of a footprint than box-girder bridges, and they look kind of cool.

Lots of cable-stayed extradosed bridges have been built in Europe and Asia. Which brings us back to the Structural Engineering Forum of India. India has many of its own cable-stayed extradosed bridges.

Writing in October of 2012, Dr. Narayanan said:

Extradosed bridges are relatively expensive and material inefficient. Almost any span that could be bridged by an extradosed bridge could be spanned more inexpensively with a continuous girder, or more efficiently (but at even greater cost) with a cable-stayed. In most cases the spans are short enough that the use of cables at all is an aesthetic rather than engineering-necessitated choice. This does not imply that is a "bad" choice, since in some cases the difference in cost and efficiency is small, and the extradosed type is a very elegant form. 

This is one person's views, although Subramanian is the author of several books on the subjects of concrete, bridge design, and related topics. He probably knows as much as the people who designed and are carrying out the Quinnipiac project at glacial speed. 

So, there you have it.  Seems like whoever runs bridge construction in Connecticut could have saved money and perhaps decades, by building a new,  bigger  box-girder bridge than by selecting a nonsensically named "extradosed" design. 

Just food for thought as you negotiate the ever-changing lanes and soaring ramps of the Pearl Harbor Memorial Bridge.

 Let's hope it is finished while veterans of Pearl Harbor are still alive. 

Extrados(e) and intrados(e) turn up all over the place, including the design of airplane wings. 

Wednesday, August 14, 2013

You Get What You Pay For, Especially In News

The sad sack who nominally runs America on Line, apologized recently for firing someone during a conference call, which is a pretty unpleasant way to act.

Tim Armstrong, AOL chief of something or other, was informing other AOL middle managers that he was considering pulling the plug on Patch. Patch is a service provided mostly by would-be writers and masochistic "editors," who search for the "hyper-local" and post stories on the Patch web site, wherever that is.

Something like that. My impression is that editors break their backs re-writing everything, posting everything, and whatever else constitutes everything. Some media outlets call Patch AOL's "media and information platform." Please.

You could have seen the story in the Wednesday, Aug. 14 New York Times, which to its diminishing credit, still pays reporters, professional reporters, some of the best, to cover stories and then edit and print the stories on newsprint.

To digress for a moment,  the Times wants to be a newspaper and a Web presence simultaneously. The problem is that short of making people pay for what's free on Google news and other places on the Internet, the Times has no good way to make money on the Web. 

People will pay to watch baseball, football, or basketball -- or to watch pornography -- but otherwise, who wants to shell out cash for some intangible electrons? Even well written intangible electrons. That's why the Times loses tons of money on its Web edition, which comes out of the newspaper's newspaper division.

The newspaper on paper version sells at least okay. Many people are willing to pay along $700 a year to have the Times delivered every day. Now the Times is restricting un-paying Web readers to three stories a day. After reading three stories, you'll need to come up with some electronic dollars.

 This applies even to the people who pay almost a grand a year, sadly.

There is an alternative. What you do as publisher is invite people who think of themselves as reporters and/or writers to replace the real reporters, who frequently use to have advanced degrees in journalism. They also had experience, and more importantly, experience in newspaper writing.

Trust me, teaching people to write like seasoned reporters is not easy. Not in the least. Might be easier to teach them Mandarin or linear algebra. 
Following that formula, you the published, get something along the lines of Patch. Or, worse yet, "the Examiner," which pays its "freelance writers" one tenth of a cent per Web hit. Kind of hair-raising.

Ultimately, it made sense for Armstrong to downplay Patch by firing and humiliating an otherwise loyal employee.

 Better to be seen as a lout than the money-hungry purveyor of maybe-news by amateurs. 

To Heck With Cancer in Google Land

Last night I had occasion to purchase online two T-shirts that read "Fuck Cancer."

I'm entitled to buy them because I have/had/am having head and neck cancer.  Part of my throat was removed in April and then I underwent  six weeks of radiation therapy and infusions of cisplatin.

Aside from the pain and discomfort, which there is plenty of, I lost my sense of taste,  the desire to eat, some facial hair, some hair on the back of my head, and concluded with a strangely weak right arm, because surgery to remove a few dozen lymph nodes impinged on a nerve.

Also, the x-rays and chemotherapy were not beneficial to my salivary glands.

My taste and appetite returned, for the most part, my facial hair is trying to return, my arm is improving, and the back of my head may even be growing hair.  Saliva is back, most of the time.

(That is among the reasons I have not been blogging much lately).

So, I felt entitled to buy a Fuck Cancer T-shirt. 

I was not sure where I had seen them online, so I searched Google for "fuck cancer T-shirt."  But Google would not cooperate because the search is permanently set on "safe." Consequently, I turned up many anti-cancer T-shirts, but no fuck cancer.

If anyone has figured out how to turn off Google's safe search, please drop me a line. If one tries to turns if off, one is directed to "settings," which do not contain a way to turn off "safe" mode. The exercise has an infuriating circular character. 

My sense is that I could probably find all manners of hate, prejudice, violence, killing, crime. and other unsavory things on Google, no problem. Fuck cancer? Nope.

Google, for mysterious reasons, eventually "asked" me if I wanted to search for "fuck cancer T-shirts" and I responded positively. 

To sum up: I was not searching for pornography. Not every instance of a word such as "fuck" is necessarily immoral. Google's safety program cannot easily distinguish between the two.

Google eventually relented. I'm not sure why. 

But trust me. "Fuck cancer" is one of the milder feelings one has after a malignant chunk of throat is removed and then exposed to death rays and poison.

Monday, January 14, 2013

Saucers Beyond, Way Beyond, Reason

Kenneth Arnold pointing to a drawing of what he saw "skipping" like a "saucer" in 1947.
The shape looks more like a boomerang than an actual saucer.

The "secret" flying saucer that reached an altitude of 20 feet.  Inconsistent details inside!

The "secret" Avro (also known as Avrocar) flying saucer in a public display in 1958.

The idea of a "flying saucer" has managed to  become so entangled in confusion, misunderstandings,  ancient  hypotheses,  and possible government-created misinformation, that it we may never be able to consign it to the Dumpster of history.

The saucer's latest appearance is on the cover of the Feb. 13 Popular Mechanics, which carries a story about a recently declassified file containing information purporting to show that the U.S. and Canada were developing a Cold War flying saucer, with which to shoot down Soviet bombers.

A digression: Isn't it only mid-January? Is the magazine from the future? 

The box of "secret" documents included drawings, but not the kind of plans that a company would use to construct an actual machine.

To straighten out this miasma of the not-quite true and blatantly false, it helps to first understand where the concept of "flying saucer" originated. A Washington state businessman pilot,  Kenneth Arnold, was flying over Mount Rainier, when he saw a formation of unidentifiable flying objects.

Upon landing at Pendleton, Ore to refuel,  Arnold told his story to the "media." The version I like best has him describing the event to Nolan Skiff, an editor of the East Oregonian newspaper. Depending on whom you believe,  Anderson described the motion of the mysterious objects as skipping up and down like a saucer hurled onto a lake.

He did not say he saw something shaped like a saucer. Later on, he did describe the objects as saucer-lilke, convex at the front and concave at the rear, whatever that means. Skiff, or someone else, invented the word combination "flying saucer."

Arnold described what he saw as acting like saucers. Soon thereafter, some people strangely open to suggestion, started to report sightings of flying saucers. A staple of science fiction was born.

Arnold died in 1984,  at age 68, relieving him of having to describe what he saw over and over and over and over, if, that is, he saw anything.

The fable continues in the mid-1950s. Depending on the narrator, either the Nazis had been working on a flying saucer, or the idea simply occurred to a Canadian John "Jack" Frost, who worked at an aeronautical company called Avro Canada. Frost, somewhat optimistically, predicted that a saucer-shaped airplane could travel at four times the speed of sound at more than 100,000 feet.

The real flying pancake designed and built by Vought in the late 1930s

The next part of the tale starts to get more and more complicated. For starters, the U.S. aviation company Vought  proposed a circular craft, which became known as the "flying pancake," in the years before World War II.

Vought, in Stratford,  also manufactured the famous F4U Corsair fighter that decimated Japanese aircraft during the war in the Pacific.

The plane's designer, Charles H. Zimermann,  came up with a flattened, cylindrical fuselage, which had two engines in the front and stabilizers in the back. Note that the plane vaguely resembled a pancake, especially after a 1939 prototype was painted in Navy colors of the time, yellow on top and silver on the bottom.

The XF5U never entered service and did not acquire a fighting name. It is now in the Smithsonian.

The flying flapjack was aerodynamically sensible and a flattened disk with an oval cross-section minimizes drag and maximizes lift. Note that it has a front end and a back end. The fuselage was intended to go in one direction.

Flying saucers, however, spin. At least in the movies. So one way or the other, either the front or back, both and/or neither is rotating around you.  Somehow. Helicopter blades and rotors are complex, but nothing compared to engineering something piloted that revolves at perhaps 10 times a second.

The saucer, code named 1794-A had no front or back and drawings and photos in Popular Mechanics indicate that it did not spin. Consider the difficulty of a spinning disk manned airplane. How would it maneuver? How would it travel in a straight line? Or Turn?  How about the problem of torque? And what would connect the pilot and controls to the rest of the craft?

Some images of the secret saucer show it spinning. Others do not. Some show a fan-like "turbulator" in the center, others, do not.  Popular Mechanics shows both. Also, a drawing of one with a pilot's seat in the middle.

Project 1794-A does not spin, but is "omnidirectional," meaning it has no "back" or "front." Jet engines are buried in the craft, and are vented to the surface through complicated gated slots. The principle that was supposed to make this thing fly is called the Candoa effect.

This effect is named after Romanian aerodynamic physicist Henri Candoa, who realized in 1910 that the effect could play a role in airplane design. The actual effect was described by Thomas Young in a lecture to the Royal Society in England in 1880.

In essence, the Candoa effect is what makes water run down the side of your glass and under your glass, when you are trying to pour a glass of water, or some other liquid, into another container. It is what causes liquids and gasses to cling to curved surfaces. Something like that.

The Avro Car 1794-A employed Candoa to provide lift. Jet exhaust would speed out and over the smooth surface of the saucer and gather under the craft.  This was somehow going to make the craft travel at Mach 4. A "secret" flight test in the mid-1950s found that the craft could climb no higher than 20 feet.

The U.S. Air Force canceled its part of the project in 1961, by which time conventional airplanes with fuselage, empennage,  wings, and vertical and horizontal stabilizers were reaching Mach 2 and beyond.

If there's any irony here, it's that the Vought flying pancake could actually fly, and if powered by World War II era jet engines, may have reached 550 miles an hour. If only Arnold had been flying over Stratford instead of a volcano in Washington and a decade or so earlier.

Flying saucers, as they inhabit the imagination.

To be fair to Popular Mechanics, what they show photos of actually does or did exist. But the implication that the Avro was a big secret until now is just silly.

As for Kenneth Arnold, why didn't he, at some point, clarify his description of what he apparently saw?  What if he'd said the mystery craft were somehow acting like teapots, would everyone assume that they looked like teapots, and start seeing teapots?

Remember then: If you think you see a saucer-shaped UFO, than either the aliens are in on the joke, it's an incredible coincidence, or you're seeing something that was suggested to you that does not really exist.

Were the Germans really doing flying saucer research before "flying saucers" were known to allegedly exist?
This one does not look heavily armed.