Jun 11, 2022
It's time for a new puzzler. I wish we had a good one to share, but we have this one instead.
Our old mechanic Crusty, after he left us, he decided to tour the United States. And from time to time he would correspond with us.
He was living in a boxcar in a train yard someplace in Pennsylvania. And he said, "Gee, guys, I've noticed an interesting phenomenon about freight trains. Freight trains frequently have to stop to discharge cargo from the train cars. And the train has to stop at a loading and unloading dock. And it's important that the car winds up in exactly the right spot. So that they can open the door, and use a forklift to empty the train car of its cargo. And once they are done, the train takes off."
He said, "I've noticed that in almost every case, the train stops and they miss the dock. They go passed it and then, they back up. And when they back up, they hit it right on the nose. Now, why couldn't they kind of just ease up to it real slowly? They could slow down in anticipation of the stop and hit it right on the nose. But they don't do this. They go past it and back up. They do this all the time!"
And he thought it was kind of interesting. He said, "I know why they do it. Do you?"
They are purposefully overshooting the mark.
Why do they do that?
So puzzler answer!!!
So the train operators, always overshoot the spot when getting ready to offload their cargo. They overshoot it, and then they have to back up to the perfect spot. They are experts at their jobs, so I'm sure they could just hit it right on the mark the first time, but they don't. They always overshoot it, and then back up. And we want to know, why do they do that?
Here is the answer.
The reason they do this is that if the train were to just stop perfectly on the stop, all the couplings would be in a fully expanded position. There would be a lot of space between the cars, and the coupling would be extended all the way if you stopped like that.
But the train operators don't want that to happen. Most people think of trains as one singular, monolithic thing. But the truth is, trains are made up of a bunch of different, heavy cars. Individual train cars that are all coupled together. So, when you overshoot the mark and then back up, you get to compress all the couplings together. By doing this, when the train starts to take off again, the engine begins to pull one car at a time. This allows the train to start off without having to pull the whole train at once. So instead of pulling 100 cars all at once, it pulls the first one and the second one, and so on. The engine gets to build up some momentum this way, otherwise, the train engine would just sit there and spin its wheels under all that weight.
