this post was submitted on 26 Mar 2024
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Everyone's blaming the ship, but the bridge should have been built to withstand such an impact.
Edit: Tell me you don't know that pier protection systems exist with saying you don't know that pier protection systems exist.
https://www.repierson.com/projects/drba-ship-collision-and-protection-system/
Just one example of such a system.
The bridge you linked likely wouldn't have been able to withstand the collision of this ship at one of its pillars. Assuming that the numbers are for a fully loaded ship at 120,000 DWT at 7 knots, it could only take about 90% of the momentum maximum that the Dali had (116,000 DWT at 8 knots) at once.
For my American friends that's about 27.56 fully loaded F-35Cs going max speed (Mach 1.6) at the same spot at the same time. Or 312 M1A2 Abrams.
I'd have to look at shipping logs and whatnot to say whether that specific protection system is sufficiently rated for the traffic going under that bridge.
And I mean, come on, the fact that a completely random protection system I pulled up can "only" withstand 90% of the impact we're interested in is not a fucking gotcha. It's evidence that this kind of system is completely reasonable for this kind of impact. Engineering, physics, and numbers don't work this way, but shit, scale it by 20%. Tada.
Ok but that relies on them knowing that they'd be hit by this exact size ship in the future. Hindsight is 20/20. The Delaware Memorial Bridge is within 10 ft of clearance and is about 2,000 ft longer than the Baltimore bridge, and both would take vessels of this size, why would they just randomly decide to scale the same kind of system by the number required to stop the bridge from collapsing from being hit in this specific scenario (or more) for the Baltimore bridge?
Also what's with the "only"? If it doesn't work, it doesn't work. It'd hypothetically still collapse the bridge even if the system were effective for ships 90% of this ship's weight.
Failure in an engineered system is rarely a binary condition, though the FSC bridge is a type that fails catastrophically once you fully remove that pillar. But, recognize that you can damage the pillar without removing it.
Anyway, the protection system necessary for the bridge isn't just a factor of the design of the bridge. Like I referenced in the previous comment, it's dependent on the traffic going under. The world's biggest bridge would never need a collision protection system if the boats going under were small enough.
This isn't a hindsight problem. Bridges have known traffic under them and should be rated to withstand impacts. It's extremely easy to predict what the largest possible impact is for a particular bridge and plan accordingly. Do you think this boat was lost? This particular boat probably passed under that bridge a hundred or more times before it malfunctioned and hit it.
Look at you out here victim blaming a bridge.
Uh, yeah, that's how engineered safety systems work. House fires have been getting rarer in the developed world because building materials have become less flammable (among other reasons). We didn't just blame the people who started the fire, we also changed their environment to make it less flammable.
Yes, the boat is partially to blame, but the bridge should have also been able to withstand the impact.
I like when I make a shit joke and end up learning something.
It was a good joke, 10/10. But as you can see from this thread, we have a tendency to only blame the obvious action that directly led to the problem. That's good and necessary (we will find out why this boat lost power) but we should also look at any secondary ways to reduce the impact of failure.
I am actually fun at parties, you'll have to believe me. Engineered safety systems isn't a common conversation topic at parties.
If your gonna explain to me something I don't know about then I'm ready to party!
Liz, can you go back to working the register at the Quik Trip and stop getting high behind the dumpster and making comments on Lemmy? K? Thanks.
Can you point out any bridges are built to withstand 100,000 ton ship directly colliding with them?
For whatever reason I don't think you've done the math.
The point of most bridge protection systems is to stop a ship before it can directly collide with it. They are usually separate structures.
I think you have to look at natural bridges like Beringia for that kind of durability, which would be unfeasable to build as standard infrastructure
97,000 tons moving at just 3mph would be sooo much force. I'm not sure what type of bomb it would be equivalent to but I don't see much stopping that.
I'm coming up with 1000lbs of TNT. I have no idea what I'm doing though and the conversions are apparently controversial.
You can hit the standard bridge with 19, 19 hand high horses with a standard 15 meter trebuchet; assuming all shots are places back to back in under 7 minutes.
If it is built to withstand such a horse thumping, it is given an A rating by the Bridge Association of America. (BAA)
Some of this may be controversial though.
does range come into play here?
It shouldn't. A trebuchet is a superior siege engine with great horse tossing ability. What might factor is whether it is riderless or not.