NTSB Board Meeting - 2022 Fern Hollow Bridge Collapse

[@Cadcare]

Foreign observer here. I do however, document civil structures and have done so for many, many years. I am not a structural engineer. What comes to my mind is a quote from Shakespeare, “Something is rotten in the state of Denmark.” Chose your "Denmark"!

[@qbi4614]

So BIG rust holes was the cause! To the point where crossbracing rusted off. Who would think that!?

[@danlowe8684]

Corten steel is not recommended for wet locations. The underside of a bridge is not supposed to be wet. The failure to maintain the storm drainage system rotted the steel. The failure to address the obviously rotted steel problem - even after receiving tweets from trail walkers displaying metal parts no longer connected to bridge - took the bridge down.

[@jasonswift7098]

Yeah ok expert

[@danlowe8684]

Only 35 years in the industry, kiddo.@@jasonswift7098

[@BigEightiesNewWave]

All this fancy-speak, for We never did any maintenance.

[@captiannemo1587]

I would hope the added regulation and maintenance costs for working in a parkland environment over a waterway was covered…

[@DanFrederiksen]

I'm not a bridge inspector but to my engineering sensibilities any kind of section loss, even 2% sounds unacceptable to me, let alone 100% loss!!! If the surface coating premise held I would think we would be talking microns, not inches of erosion. Was the metal tested for the right composition? the widespread erosion strikes me as much greater than intended. Was it a particularly difficult climate in that valley or is there a general problem with the design. And overarching everything, is it too obvious to suggest a material choice with a life expectancy in the hundreds of years? as opposed to the titanic here. Since servicing is inconvenient and municipalities are averse to thinking, why not do it right once and for all? Also maybe a smooth outer surface design like a closed box profile without all the bolts and ledges. A closed minimal outer surface should be easier to defend. The use of high strength steel might also quickly pay for itself in the much lower weight. And if possible maybe even a carbon fiber box profile bridge without any supports to keep it simple. With the right matrix it might last forever with no structural maintenance, only drive surface. Maybe something more high tech than asphalt if that doesn't mesh well with a rigid structure.

[@rwardenutube]

The “Swiss cheese” failure model in action - every agency failed their duty: local, state and federal.

[@josepheomelia9951]

KISS, Keep It Simple Stupid, bridge designs would help in preventing the failure due to poor maintenance. Bridges that require a component level FEM analysis to Id critical members should not be used. We are not designing airplanes. On Fern Hollow I would not be surprised if the design used Hardy-Cross in the design calculate the bending moments in the legs.

[@RGB06084]

AKA: Frickin Bridge!

[@dissaid]

🙏🙏🙏

[@stacey4u2luv]

Keep your money at home and repair your home.

[@noheader]

built back better

[@samreitzes4922]

That's not true it's a big ship hits it no matter what the bridge wouldn't have problems maybe not as bad problems. People so lazy nowadays what would you not check the bridges more often because they don't care they just want free money they don't want to work

[@ellwoodyuengling8207]

👏 Promo'SM