06/Sep/2010

Setting things straight

9 replies to “Setting things straight”

  1. Yes, Mar is definitly nerdy :D

  2. Pravas

    Can we please see some more nudity? Please?

  3. crobbins

    Umm, steel on steel friction is what is needed for locomotives to move. And "... overcome by simply moving a larger at once." makes no sense at all.

    • Sheela

      "..by simply moving a larger mass at once." was what it was supposed to say, but I forgot to put in the "mass" bit, but I cannot edit it now.

      Basically, moving a 1 ton payload makes no sense if the train itself weighs 20 tonnes. Moving 500 tonnes is better, because then the weight of the train is less of a problem in the overall expense.

      As for steel on steel needed for a train to be a train ... well, not really. The first trains was actually big tractors pulling old wagons. Also, look up Australian road train.

      • crobbins

        "As for steel on steel needed for a train to be a train … well, not really. The first trains was actually big tractors pulling old wagons. Also, look up Australian road train."

        I said friction, which happens to be steel on steel in this instance, is needed lest the iron horse just sits and spins. Railroad engines to this day carry sand reservoirs to INCREASE friction when needed. Whatever your definition of "train" has to be, for an object (including your body) to change locations it needs enough friction to overcome inertia (move.)

        • Sheela

          That is correct, some friction is indeed need in order to make the body move, or even stop.

          However, the steel on steel wheels 'n' track was indeed choosen because of it's low friction to begin with. The reason being that it originated in the british mines where they used horse drawn carts, and thus the less friction, the more payload the horses could move.

          Railroads actually started out as a bunch of wooden planks laid out on the ground, with sheet metal nailed unto them, and cards with wooden wheel that had a metal ring around them. All done in the attempt to lower friction.

          Offcourse, they had problem with them derailing, so they made them into small grooves in the ground so the wheels would self align with the grooves. But that has the problem of dirt and gravel getting in there, increasing the friction.

          So a bright man did the opposite and raised the tracks over the ground, and added a flange to the wheels, so they wouldn't derail.

          Even then, they were only moving one wagon at a time, and they were not exactly what we would consider a modern version of a train.

          Then one of the developers heard of an american that used a steam tractor that pulled many wagons all at the same time, trough swampy areas. He added that to the mining carts, and we ended up with a steamengine in the front, and a bunch of mining carts hinged to eachother, riding on steel wheels running on steel tracks. The engine had a gear that hooked into a toothed track, so it could pull itself up the steep inclines in the mines, thus defying the lack of friction in the steel wheel + steel track combination.

          The main thing is, Steel Wheels on Steel Tracks was chosen because of it's low rolling resistance, it's ability to move heavy loads and it's longitivity.

          It wasn't until later that they ran into the problem of not having enough traction to move the load. Which they geniously solved by pouring sand on the tracks.

  4. Sheela

    Ohhh ... that's a good save there.
    Seems he might have some skills to him.

    And Mar got a date !

    Seems both the characters and the comic itself is having success right now. Speaking of which, Drowemos of Exiern made a post on what he thinks makes a webcomic successful : http://www.exiern.com/?p=973



    As for the nerdiness, the correct conversion would be reciprocating force from the prime mover (feet on pedals) converted into rotational force (bicycle wheel), which in turn becomes a lateral pushing force which moves the bicycle forward (tyre on ground).

    A simpler way would to simply put the feet on the ground and push the bicycle forward, but that has serious limitations on the speed that can be achieved.

    However, the main reason why this works so well is the lowering of the friction of the mass moved across the ground. This is obviously done using wheels, or even better, wheels with ballbearings.

    Interestingly, this is exactly how old steam locomotives worked too, but instead of feet pushing on the lever, a piston did the grunt work. But, being clever as engineers are wont to be, they used metal wheels on metal tracks to lower friction even more, making trains the most efficient way of moving heavy weight from point a to point b. Unfortunately, the trains themselves are pretty heavy too, so a lot of the gains are lost there, but can be overcome by simply moving a larger at once.

    I could continue, but I think this is enough .. for now. :D

    • Inky

      Oh wow! But an explanation like that would probably not sound very natural coming from Mar (and would take too much dialog). I only think it's interesting because it is clever and simple. We push with our legs in a way that is not natural to use for our own displacement. And it's fun.

      Um, I can't compare to really successful comics. You may want to read that same post here, in the context of a forum.

      • Sheela

        No no, we don't use our legs to make displacement, we make movement! Displacement is the kinda stuff you have in the cylinder of a combustion engine!

        But yes, bicycles are neat !

        And tricycles too!
        Like this one ( http://www.go-one.us/Pictures_of_go-one3.html ), which is both cool and efficient, but also rather expensive!