Today, Vladimir Shukhov's hyperboloids. The University of Houston's College of Engineering presents this series about the machines that make our civilization run and about the people whose ingenuity created them.
It seems a Russian landmark is going to be demolished: the 525 foot Shukhov Radio Tower. It was finished in 1922 and it's an early surviving example of what's called a hyperboloid structure. (If you're hearing this in reruns it might be long gone. Otherwise, you might want to include it in that next visit to Moscow.)
The familiar cooling towers for nuclear reactors are hyperboloids. Imagine a long thin vertical hyperbola rotating about an axis alongside it. The resulting shape is a tower that flares at the top and bottom. It's very strong since it has a double curvature: Its sides bend outward, its cross-section bends inward.
We create that kind of strength when we eat pizza: Hold a slice flat and it just bends down. So we bend the sides of the slice upward and it resists flopping downward. Try to bend any surface in two directions, and its tensile strength resists us.
Illustration of double curvature strength: A piece of paper shaped like a pizza slice supports a cantilever load when it's forced to bend in double curvature. (Photo by John Lienhard)
Enter now, Vladimir Shukhov, born in 1853. He studied engineering at the Imperial Moscow Technical School and later became what some have called, the Russian Edison. [But, unlike Edison, he had powerfully-honed academic skills.]
He created the Shukhov cracking process for the oil industry. It was the industry standard until catalytic cracking replaced it. He redesigned city water mains - invented oil pumps, tanks, pipelines, and tanker barges. He also did early art photography. And the theme of beautiful strong surfaces ran through his work.
Shukhov built the first hyperboloid structure - a water tower for the 1896 All-Russian Exhibition.It loomed 120 feet over the grounds and still stands in Nizhny Novgorod. He used double curvatures in other pavilions, in giant arches ... in factory buildings.
The Russian Revolution had morphed into civil war by the time Shukhov proposed what was to be his crowning achievement - a 1150-foot radio tower in Moscow. Lenin made him scale his ambitions back to the present tower. But that's almost the height of our Washington Monument. To build it, Shukhov stacked six diminishing hyperboloids on top of each other. The gossamer result looks like a long, rippled, skinny dunce cap of open meshwork.
The tower has fallen into disrepair over the years. Vladimir Putin finally authorized some four million dollars to restore it. But, as engineers see the extent of decay, that seems impractical. Perhaps the tower could be rebuilt according to Shukhov's old plans - the existing one is toast. But Shukhov's idea lives. So many such towers have sprung up. Cooling towers, and much more. The Chinese have built their great two-thousand-foot hyperboloid Canton Tower.
Left to right: Maxim Federov's photo of Shukhov's Moscow tower at night, Shukhov's original tower at the All Russia Exhibition in 1896, and China's 1969-foot Canton Tower.
And what about Shukov in the violently shifting politics of the Revolution years? He once wrote, "We should work independently from politics. Buildings, boilers, beams would be needed and so would we." He survived the purges, died a natural death in 1939, and his hyperboloid design is now familiar architecture.
I'm John Lienhard at the University of Houston, where we're interested in the way inventive minds work.
See the following 2014 article about the Shukhov Tower, also called the Shabolovka Radio tower by The Guardian.
Note that Shukhov's original design was to have a stack of nine hyperboloid structures. The final tower had only six. His original tower at the 1896 Exhibition and the Canton Tower both go all the way in one hyperboloid.
My thanks to Dr. Ashutosh Agrawal, UH Mech. Engr., for providing the pizza example in the context of a lecture on cellular surface strength. All images except for my one photo, are courtesy of Wikimedia Commons.
This episode was first aired on March 24, 2014