• marxismtomorrow@lemmy.today
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    3 months ago

    So you think a ship that was moving at maybe 5 knots/hr instantly turned around and in less than 30 minutes accelerated past 50 knots/hr?

    • apparia@discuss.tchncs.de
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      3 months ago

      I don’t know where you’re getting any of that from. It was travelling at 8 knots before and after the turnaround. The bit in the animation where it slows and drifts almost due south is actually marinetraffic not having AIS data for that period so it just interpolates between the two known positions. Maybe I should have made that clearer.

      That turnaround period is also close to 3.5 (edit: 2.5) hours, not 30 minutes.

      According to the same data the ship is now close to the Strait of Hormuz that it passed through yesterday; it seems pretty clear it did not get where it wanted to go.

    • SaltSong@startrek.website
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      3 months ago

      The fact that you are measuring speed in knots per hour invalidates your point.

      Please use a correct measurement, and try again.

          • SaltSong@startrek.website
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            3 months ago

            I’m being accurate. “Knots” is “nautical miles per hour,” as you correctly described.

            • marcos@lemmy.world
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              3 months ago

              If we are being really pedantic. Knots is a measure of distance, and the fact that people have been using that wrong for several centuries does not turn a rope tied at one point into a time-changing object.

              • SaltSong@startrek.website
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                3 months ago

                Knots is a measure of distance, and the fact that people have been using that wrong for several centuries

                We’ve only been sailing for “several centuries.” How long was it a measure of distance before people started using it wrong?

        • SaltSong@startrek.website
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          3 months ago

          I find that reasonably unlikely, unless it is a naval ship. I don’t think cargo ships go that fast unless empty, and highly motivated. Possibly not even then.

          Do we have a reliable source for this data?

          • Ilovethebomb@sh.itjust.works
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            3 months ago

            Most naval vessels can do just over 30, if that. Cargo vessels spend most of their life below 10.

            50 knots means there’s some fuckery afoot.

            • SaltSong@startrek.website
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              3 months ago

              I was under the impression that navy ships could go much faster, but didn’t because of wear and fuel consumption. I recall hearing about 60 knots, but I wouldn’t place even a small bet on it.

              Same for cargo ships, to a lesser extent. If an empty one felt a need to move, I’m sure they could get a little speed to them. But they aren’t built for it, and “saving money on fuel” is their prime directive.

              Although, as someone noted elsewhere, there don’t seem to be any actual measurements of speed. They turned around, and cranked the throttle, but we don’t know how far they were going in either phase.

              • Ilovethebomb@sh.itjust.works
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                3 months ago

                I’ve read claims that some nuclear aircraft carriers can go a lot faster than 30, but I suspect that’s bullshit.

                There’s also a phenomenon known as hull speed, where a displacement hull vessel takes an exponential amount of power to go slightly faster once you hit it. They’re also not going to have an engine that’s massively more powerful than they need, just in case.

                50 knots would outrun pretty much any large vessel on the planet.

            • apparia@discuss.tchncs.de
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              3 months ago

              Sure, but the gif doesn’t show 50 knots. The gif doesn’t show any speed actually, so I really don’t know where the 50 number comes from. But on the tracker the speed was 8.1 knots. Fast for a tanker, but totally believable.