Good illustration of the strength of an arch...

[AE-NMidlands]

A

[Oliver90owner]

Yes, but the Romans soon learned that a few soldiers marching over an arch was not a good idea!

The Victorians knew how to make things last!

[AE-NMidlands]

Yes, but the Romans soon learned that a few soldiers marching over an arch was not a good idea!
The Victorians knew how to make things last!

I thought it was only suspension bridges that were vulnerable to being driven by synchronised footfall...
Anyway, I also remember a good TV programme which showed why you need speed limits over some railway bridges. They had a simple oval of track which crossed a spindly lattice girder or trestle bridge on the straight bit. Set the train running, gradually increase the speed... everything OK until you exceed a certain dynamic loading when the bridge failed under the train.
Is the Roman bit supported anywhere? https://www.wearethemighty.com/military ... dges-myth/ seems to be only about suspension bridges...
A

[Mr Gus]

The arch (way) bridge is one tough but to crack, We had a small single track bridge connecting gairloch & Charlestown for likely 400 years (it had to take all the traffic Inc lorries) ..one night back in the early 1980's a high tide storm destroyed it.
The relentless lapping of some high tides & this occasional, exceptional, storm ripped it away in just a few hours.

The bridge was rebuilt later as a walking crossing, bypassed (across The inlet) by road building scheme monies from the European union incentive (pre eu, so eec)
The arch strength didn't count for much when the pillars were lashed so.

I hate seeing traditionally engineered bridges coming down, they have a life almost.