5 ms·
Naah, this is folklore: https://skeptics.stackexchange.com/questions/18558/were-roman-engineers-required-to-stand-beneath-their-bridges-as-they-were-tested htt
by jaclaz 8y ago
Naah, this is folklore:
https://skeptics.stackexchange.com/questions/18558/were-roman-engineers-required-to-stand-beneath-their-bridges-as-they-were-tested https://skeptics.stackexchange.com/questions/18558/were-roma...
As a matter of fact if you have a legion marching on it, almost any bridge will collapse, there is a reason why, when soldiers cross bridges they are ordered to "break stride" in order to avoid possible issues with resonance of the structure.
And of course, while placing architects and engineers under the bridge was "fair", the poor soldiers were innocent (and at the time among valuable resources to society) so their lives wouldn't have been deliberately risked.
There are some (unconfirmed) reports about the architect standing below the bridge when the scaffolding/support was removed, however.
- moviuro 8y agohttps://en.wikipedia.org/wiki/Angers_Bridge https://en.wikipedia.org/wiki/Angers_Bridge : Soldiers create resonance on a brdige, making it collapse.
- deleted 8y ago[deleted]
- mannykannot 8y agoThere is actually little evidence here that a resonance excited by marching soldiers caused this bridge to fall. The article says that, as usual, the soldiers were instructed to break step when crossing. The article cites a powerful thunderstorm, the effect of strong gusts being 'caught' by the massed soldiers on the bridge, and corrosion of the cables at their anchorages, as likely causes. A survivor reported that the soldiers were stumbling around as if drunk, and could barely stand. There was some speculation that the motion of the bridge caused the soldiers to respond in a coordinated way that exacerbated the swaying, but lurching from side to side is hardly marching. Contrary to what the grandparent post says, few bridges are susceptible to being brought down by marching.
- baxtr 8y agoI think I’ve read something similar about the ex-dictator in Albania, who would place engineers into bunkers they've constructed and then fire on them to see if they hold EDIT: found a source, seems to be a true story https://www.balkanride.com/2017/03/07/albanias-concrete-bunkers-defences-against-an-enemy-that-never-came/ https://www.balkanride.com/2017/03/07/albanias-concrete-bunk...
- booleandilemma 8y agoIt’s like dogfooding.
- wlll 8y agoThis was the issue with the "Millenium" bridge in London, renamed unofficially as the "wobbly" bridge. Because of the nature of it's construction people would over time start to sync their steps, the more this happened the more the bridge swayed and the more people synced their steps. It was fixed by adding dampers. https://en.wikipedia.org/wiki/Millennium_Bridge,_London https://en.wikipedia.org/wiki/Millennium_Bridge,_London
- falcolas 8y agoOn the note of bridge resonance, one can not forget the Tacoma Narrows Bridge: https://www.youtube.com/watch?v=j-zczJXSxnw https://www.youtube.com/watch?v=j-zczJXSxnw
- m_eiman 8y agoIf anything, the way that bridge wobbles before collapsing is pretty assuring - it’s unlikely I’d enter a bridge even remotely as unstable!
- sabas_ge 8y agoI was talking to a colleague today and I made that example I remembered from my physics course done on the Halliday-Resnick textbook https://en.wikipedia.org/wiki/Fundamentals_of_Physics https://en.wikipedia.org/wiki/Fundamentals_of_Physics
- rootusrootus 8y agoI recall that we always had to break stride when marching across bridges, but I also recall that this has long been debunked, a properly designed bridge is in no danger at all from people marching across it in step.
- seanmcdirmid 8y agoThere was that British bridge, but it was suspension: https://en.m.wikipedia.org/wiki/Broughton_Suspension_Bridge https://en.m.wikipedia.org/wiki/Broughton_Suspension_Bridge It is easy to see how a suspension bridge would resonate fairly easily. Also see the Tacoma Narrows bridge.