This is why the #VerrazanoBridge was closed yesterday during the high winds. pic.twitter.com/QrefTGHVom
— NYCFireWire (@NYCFireWire) December 1, 2020
That is a lot of high tension steel.
You know what else is high tension steel?
A guitar string.
When you add enough energy to make it resonate it’s going to vibrate like a guitar string.
In this case that vibration is at an audible frequency.
Oh my. Not quite Tacoma Narrows Bridge video, but that looks bad. Modern bridge design aims to make them stiff enough so this sort of thing doesn’t happen. For a while, bridge designs aimed for pretty rather than reliable, and the Tacoma Narrows bridge succumbed to that. A book on structural engineering I’ve read says that several other bridges (Golden Gate, perhaps) were retrofitted with deeper trusses underneath (taller box structure) to stiffen the road deck. Sure enough, if you compare the V2 Tacoma Narrows bridge with the original you can see this very clearly.
That’s partly why the George Washington Bridge has open lattice towers The original plan was to sheathe the towers in panels like the Golden Gate, or original Tacoma Narrows bridges. Fortunately O. H. Ammann was a brilliant bridge engineer so the GWB was stable and strong enough to accept a lower deck in 1959. Ammann also designed the Verrazano bridge and wrote the report on the Tacoma Narrows collapse
It’s nearly 60 Years old….
Piano strings, too. Guitar strings are under significant tension and resonate when plucked, but piano strings are under enough tension that they behave more like solid bells and chimes.
They resonate best when hit with a hammer.
I have it on good authority that a grand piano’s string snapping would whip back with sufficient speed and force to remove limbs. Some with enough to ballistically separate a man’s upper and lower halves along the waistline.
In case you needed another reason to carry a tourniquet to music recitals. 😉
This gives me a great idea. I’m going to write a book, “Piano repair for Liberals: You don’t need to be a pro!”
Holy soiled underwear, Crapman! If it hits the High “E” while you’re on it: First you fly… Then you drown. It’s science ~~ And final.
Gonna be a LOT of inspections going on…
Arecibo Observatory’s telescope/dish in PR sadly finally collapsed yesterday. I wonder if it hummed one last dying tune when it went in.