Engineer Reacts to Baltimore Bridge Collapse #construction #civilengineering

Structural engineer explains what went wrong with the bridge collapse.

[janzwendelaar]

This is true, as an engineer, I hate seeing my stuff get unengineered

[StopToBreathe]

to some people in the comments, not all accidents are preventable, therefore minimizing the damages is the only way to go.

[SaintFlyer]

Perfect example of assign your system a failure point or the system will assign one for you

[TenApplesforTime]

While this is a better design, people in the comments are kinda clueless. Complaining about a bridge not being prepared enough to get hit by a giant rig is about the same as complaining that the World Trade Center not being designed to be hit by a plane. There's things we can do to mitigate damage but there was no reasonable expectation that it would ever take this kind of impact.

[crazyguy_]

Hopefully they integrate different methods of construction into the new one so that if a collapse happens it’s only in one part and not everything. Nobody ever builds something expecting for a situation to happen. A bridge isn’t designed to be hit by a ship, a building isn’t designed to be hit by a plane, and a civilian ship isn’t designed to hit an iceberg. Accidents happen the best we can do is improve the designs so that if or when another similar accident occurs it won’t be as severe.

[RSorrows]

I came to the comments because I wanted know what those toys are. I didn't expect the mild controversy. This kind of breakdown in communication is fascinating to me.

People are missing a simple but key idea of your thesis. There's no way for the video to address the confusion after-the-fact, so people are left to extrapolate increasingly incongruent arguments. Left to their own devices, the number of responses with imperfect counterpoints creates a recursive loop that eventually makes the entire discourse collapse.

As a communication engineer, this is our worst nightmare: Seing our thesis collapsing after one misconstrued assumption.

[bobblum]

I found (and bought!) an interesting book, _To Engineer Is Human, _ which explains the balance engineers make between various factors. Safety, reliability, intended usage, the costs to build and maintain it, designed lifetime, and more. It gives real world examples.

The Francis Scott Key Bridge was built in the 1970s, I believe, and had functioned fine until this event, about 50 years. It could have remained in use for many more years, with proper maintenance. Yes, there was a risk of something like this happening, but it was always there. Have cargo ships gotten larger since the bridge was built? Has the amount of shipping traffic under it increased? Should an improved protection barrier around the bridge piers been installed long ago? I would think yes to all those.

[Borknesshas]

The bridge also isnt meant to be hit with fully loaded ocean freighters

[ronaldschild]

Thank you for going through all the effort building this model and explaining it for the layman's understanding. I will be looking closer at bridges I use a lot closer now and in the future.

[joshuahenson]

What people miss, is that while yes, if the spans were independent the failure is minimized, however by making the segments continuous over the supports, the forces in the truss members are GREATLY reduced. Without that reduction, the bridge would have been 2-3 times as tall to handle the extra load. It should also be noted that this bridge was 3 spans, so you would have lost 2/3 of the bridge anyway.

[demonicturtl]

I once designed a bridge at school it was a competition with all math classes and my design was within budget and regulations and could hold a new born baby we were the best bridge in the school and I was so proud it's still standing to this day in my friends closet

[notamouse]

Of course, the real problem with the design was a lack of concrete and earth barrier islands adjacent the main traffic spans of the bridge. That would have permitted a massive boat to hit the bridge without damage surpassing $10M to the bridge. Sure the boat might run aground, but the boat and cargo should be insured for that.

[Vodki]

So you prefer shear connections over moment connections. Architect here, i was working on a building where we were demanding shear connections but got moment because the rigidity of the joints contributes to the load transfer and you can use smaller sections/ less metal to achieve the same structure. So im assuming the choice of connections in this bridge came from saving material

[Legenerale]

This is my new favorite channel! Love the explanations and visuals

[yewo.m]

I find it very interesting. So sometimes you have to make some parts weaker in order to make the whole structure stronger

[RainerNSR]

People need to really appreciate the honesty of when someone says, not if but when it fails because nothing is meant to last forever and never take anything for granted

[somaday]

Cantilevered design. Efficient, and not the worst nightmare. Better to spend the money on prevention such as more and more capable dolphins and skirts.

[aidanatkinson]

I mean honestly it was an older bridge built on a budget. To have the multiple columns of support everyone’s talking about your going to need Atleast 2 more pillars. That bridge is specifically spaced to allow certain size vessels through. Adding 2 more big ass pillars will certainly have an impact on the size in the harbor. Btw I drive i95N to 395 into the city almost everyday. Hell I live in Baltimore.

[Hydra-cyyg]

As a structural engineer in college he’s absolutely right as the bridge was made to uniformly distribute the load across in the event of something like this, except the force exerted on the bridge was much greater. It absolutely could have been fully prevented with a different support design however, it would have cost more and would have been seen as unnecessary.

[AustralianAviator]

We have an example of a bridge that has the ‘progressive collapse’ design in Hobart, Tasmania, Australia. The Tasman Bridge that spans the Derwent River was hit by a ship in 1975, and one of its pylons was taken out. The bridge is still standing today because of this design and with a reinforced section where the pylon used to be.