• no banana@lemmy.world
    131·
    2 months ago

    I have never thought about the fact that manhole covers need to hold up to weight. Of course they do and it’s perfectly normal and sensible. It’s just not a thought I’ve ever had.

    • 9point6@lemmy.world
      80·
      2 months ago

      Technically it’s the manhole covers that need to support the weight.

      Manholes themselves are expected to do the opposite of holding weight

        • WldFyre@lemm.ee
          8·
          2 months ago

          Structures underground experience buoyant forces that act to push them up. Manholes (and any structure bottom, like storm inlets, pump station wet wells, etc) need special consideration since they can be partially or mostly hollow, so they have to be heavy enough to remain in place.

          • usualsuspect191@lemmy.ca
            5·
            2 months ago

            You know, I knew that but couldn’t figure out what the opposite of weight was for some reason. Thanks for the extra learning!

            Fun fact: Coffins experience this force too, and during flooding can rise up out of the ground

            • superkret@feddit.org
              2·
              2 months ago

              Ah, that explains why my grandpa was buried in a lead coffin.
              He lost a lot of weight right before he died, so he was too light!

          • bnaur@lemmy.world
            2·
            2 months ago

            Right, so the light is actually pushed up by these buoyant forces and I guess that then also explains why it’s so dark underground. Fascinating how learning some little new details about the world can sometimes make it all just click together!

            But does that mean that light is actually hollow?

            • Enkrod@feddit.org
              2·
              2 months ago

              Well we know light is concentrated into comparatively tiny, but heavy points in the universe (stars), while dark fills the vast vacuum of space. So light in itself is likely denser than dark, ergo the light we have on earth must be forming hollow structures to remain lighter than dark when comparing by volume.

      • grue@lemmy.worldEnglish
        41·
        2 months ago

        Technically, the walls of the manholes, in turn, support the weight of the cover and whatever load is on top of it. The entire manhole is a weight-bearing structure.

    • Whelks_chance@lemmy.world
      20·
      2 months ago

      For formula one races they weld them down to stop the cars incredible downforce from sucking them up into the air. Even then they sometimes get torn up and thrown around.

      Very important to take them seriously.

    • x00z@lemmy.worldEnglish
      5·
      2 months ago

      Manhole covers are also a common exercise for engineering students. Like designing one that can hold x amount of weight with a specific set of limitations and/or requirements.

  • Red_October@lemmy.world
    109·
    2 months ago

    Obviously in the dystopia of Night City, lighter weight manhole covers were approved for road use purely to cut costs, and any deformed or destroyed covers have the cost offloaded to the poor rube who last ran them over.

    • Kusimulkku@lemm.ee
      8·
      2 months ago

      Most of the complaints about bugs in this game seemed overblown

      You should’ve tried it on PS4 at release. It was glorious. I did have a ton of fun because of the bugs (couldn’t progress in the game much) but if I had paid for it I would’ve been pissed

      • BenLeMan@lemmy.world
        5·
        2 months ago

        And nowadays they are supplemented and partially superseded by European EN directives. This is the kind of stuff that hardly anyone realizes but is enormously helpful in everyday life. Your toilet seat breaks, you just go ahead and buy a new one. Its mount points, dimensions, and load bearing characteristics are standardized so no need to get a degree in toiletology or whatever. Just buy any one you like. Same idea with light bulbs, printer paper, piping connections, door jambs, etc. etc. Standardization makes life SO much easier.

        • idiomaddict@lemmy.world
          3·
          2 months ago

          This is something I’ve noticed since living in Germany. I’m from the US, so I don’t know if it’s a metric:imperial thing or a German specific thing, but things are way more standardized here.

          You’re not always allowed to fix your own appliances (or you can, but your insurance will be nullified for any even remotely related- like replacing the foot on a washing machine means that water damage from an unrelated leak in the washer’s drum years later may not be covered), so the standardization doesn’t always pay off, but it’s definitely standardized.

  • zaphod@sopuli.xyz
    42·
    2 months ago

    It’s not a bug, it’s a feature, in this dystopian world nobody cares about manhole cover standards anymore.

  • jaybone@lemmy.world
    152·
    2 months ago

    These numbers don’t align though. 4271 is not a Bxxx or Dxxx and also isn’t on that diagram on the left. I’m so confused rn.

    • 9blb@feddit.org
      24·
      2 months ago

      B and D are weight classes. B 125 is tested to 125 kN, D 400 is tested to 400 kN.

      DIN 4271 tells you how manholes of class B are to be build.

      • jaybone@lemmy.world
        61·
        2 months ago

        I see the number in the diagram now after looking more closely. Also seems the number is upside down in the game.

  • huginn
    5·
    2 months ago

    Wintermute would complain about such mundanity.