• hemko@lemmy.dbzer0.com
    link
    fedilink
    English
    arrow-up
    36
    ·
    3 months ago

    I wonder how much energy it would require to fling a warship from, say, NATO lake to Moscow.

    • _stranger_@lemmy.world
      link
      fedilink
      English
      arrow-up
      35
      ·
      edit-2
      3 months ago

      Oh I’m going to do the math on this:

      assuming the warship is being fired from a naval gun of truly massive proportions based on the AGS Mark 5, firing a saboted warship based on the LRLAP ( since they were made for the Zumwalt class and cost a million a round, making them the obvious best choice.)

      And why not, let’s also make the warship a Zumwaltz class, for flavor synergy.

      The LRLAP weighd 225lbs and had an effective range of 150km, so thats ~ 100kg at 150km, and it would travel at 825 mps, let’s say ours needs to go 800, were in no rush.

      Projectile Mass: A Zumwalt weighs, rounded down, 15,000 long tons, which is 15,240,704 kg Let’s say 15,000,000 kilograms. They emptied it, unloaded the ammunition, decommissioned the AGS, so it weighs a little less. Zumwalts are 610 feet long, let’s make that 1000 total to account for an aerodynamic sabot and charge, so 300m. The bore length was 378" and the shell 88", so that gives us a ratio of 4.29:1

      Our barrel is 1287m long, let’s just say 1200m.

      Saboted Zumwalt: 15,000,000Kg

      Barrel length of gun: 1200m

      Distance: We’re gonna park this gun on Gotland, middle of lake NATO. Well need some space, and that’s right in the middle. It’s 1,168.31 km as the crow flies, so we’ll round up to 1200 km.

      So, our 1.2Km long nuclear cannon would send our saboted 15,000,000 ton Zumwalt 1200km @ 800 mps, requiring 1200 Kilotons of energy, rounded up. The boat would be in flight for about 25 minutes.

      My math is quite accurate, please do not double check it.

    • CanadaPlus@lemmy.sdf.org
      link
      fedilink
      English
      arrow-up
      9
      ·
      3 months ago

      Probably depends entirely on the aerodynamics involved, if we’re assuming it’s approaching as an aircraft. This is kind of an intermediate range, and it has shitty ballistics, so the energy to just get it off the ground will be dwarfed.

      • hemko@lemmy.dbzer0.com
        link
        fedilink
        English
        arrow-up
        10
        ·
        3 months ago

        This is NCD, ignoring air resistance or at very minimum using wildly incorrect values is expected

          • hemko@lemmy.dbzer0.com
            link
            fedilink
            English
            arrow-up
            12
            ·
            3 months ago

            So I did some math, and I’m assuming we need about 1/3 of LEO velocity, it would take 707 SpaceX Starship launches to throw USS Abraham Lincoln to Kremlin.

            This is of course ignoring air resistance, other physics and common sense + we’re assuming spherical aircraft carrier

            • hemko@lemmy.dbzer0.com
              link
              fedilink
              English
              arrow-up
              7
              ·
              3 months ago

              Okay this might get little bit too credible, but if we were to disassemble the aircraft carrier in 150t pieces and launch to low earth orbit, assemble it again there and then use 1 more starship to slow it’s velocity to deorbit and drop it to target, we would need little over 2100 starship launches. Little bit more if we cover the ship with heat tiles to protect during re-entry.

              Honestly this seems well worth it considering how much cooler it would be than the usual designs for kinetic orbital strike.

            • CanadaPlus@lemmy.sdf.org
              link
              fedilink
              English
              arrow-up
              6
              ·
              edit-2
              3 months ago

              Did you get the 1/3 number somewhere? St. Petersburg is on the Baltic, and Moscow is only like 600 km away.

              I’m sorry, I’m sorry. I can’t stop.

              • hemko@lemmy.dbzer0.com
                link
                fedilink
                English
                arrow-up
                6
                ·
                edit-2
                3 months ago

                Yeah I did some research and calculations, and pulled that number out of my ass

                Edit:

                Based on this guys math which I trust as much as anything in this community, you’d need 9522km/h velocity, which is pretty damn close to 1/3 LEO velocity (28000km/h).

                This makes my ass scientifically proven

        • CanadaPlus@lemmy.sdf.org
          link
          fedilink
          English
          arrow-up
          7
          ·
          edit-2
          3 months ago

          If you throw it, and it doesn’t go into space, a rock is an aircraft.

          Source: Am an airforce geologist. /s

    • CookieOfFortune@lemmy.world
      link
      fedilink
      English
      arrow-up
      9
      ·
      3 months ago

      So let’s you want to yeet this over 1000km from a NATO country to Moscow.

      You’d need at least 3000 m/s of velocity to do this (a ton more since this without air resistance).

      A fletcher class destroyer is around 2000 tons.

      So you’d need more than 8 terajoules or 2 kilotons of TNT.

      • Trainguyrom@reddthat.com
        link
        fedilink
        English
        arrow-up
        2
        ·
        3 months ago

        You’d need at least 3000 m/s of velocity to do this (a ton more since this without air resistance).

        Sounds pretty doable with enough boosters and struts. Pretty sure I’ve flung worse in KSP

    • Skua@kbin.earth
      link
      fedilink
      arrow-up
      9
      ·
      edit-2
      3 months ago

      For these purposes I am, of course, assuming that air resistance doesn’t exist. Which would probably increase this answer by a lot.

      Narva bay to Moscow = 713 km Fully loaded Arleigh Burke destroyer displacement = 8,432,800 kg

      v = launch velocity d = horizontal distance = 713000 m θ = angle we’re launching the ship at = 45 degrees g = acceleration (from gravity) = 9.81 ms^-1

      Range of a projectile equation:

      d = (v^2 sin(2θ)) / g

      Rearrange to find v:

      dg = v^2 sin(2θ) dg / sin(2θ) = v^2 v = (dg / sin(2θ))^0.5

      Plug our numbers in:

      v = (713000*9.81 / sin(2*45))^0.5 v = (6994530 / 1)^0.5 v = 2644.72 ms^-1

      So we need to launch at 2,645 metres per second (9,522 kph, 5,917 mph). To get the energy, we use the kinetic energy equation:

      e = 0.5 m v^2 e = 0.5*8432800*2644.72^2 e = 29,491,794,808,885.76 joules e = 29.5 terajoules

      For comparison, the nuclear bomb dropped on Hiroshima exploded with about 60 terajoules of energy. So once you account for air resistance you’re probably looking at a nuke of energy.

      • hemko@lemmy.dbzer0.com
        link
        fedilink
        English
        arrow-up
        10
        ·
        3 months ago

        Honestly that sounds pretty good actually. We get to nuke something AND we get to throw a fucking ship to Moscow