• BraveSirZaphod@kbin.social
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        9 months ago

        “Bump” is a galactically humble description of a collision with a container ship weighing nearly 200 million pounds.

        To illustrate this more cleanly, the momentum of a loaded Boeing 787 flying near top speed is 17,760,000 N.s. For this ship going at just 10 km/h, the momentum is about 260,600,000 N.s. In other words, the bridge would need to be able to sustain the equivalent of 14 9/11 attacks, simultaneously.

        The way to tolerate incidents like this is to add multiple points of isolated failure so that even if one point is catastrophically destroyed, only a portion of the bridge goes down while the rest remains intact. I don’t think there are many, if any, structures on the planet that can withstand that much force

        • RubberElectrons@lemmy.world
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          9 months ago

          This right here. You’d need a frankly ridiculous amount of solid stainless steel to build pylons for seaway protection, and that’s for low speed impacts.

          Kinetic energy increases with the square of velocity!

          I’m not a sailor it anything, but I suppose requiring tugboats for all harbor travel of shops over a gross weight might be a good thing. Makes more jobs, at least.

        • bbuez@lemmy.world
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          9 months ago

          Also in designing such a resilient bridge, don’t forget one of the design requirements is to allow access to a busy shipping port

      • Passerby6497@lemmy.world
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        9 months ago

        Saying the bridge was bumped by the cargo ship is like saying someone got bumped in the head after having a brick thrown at them.