Each rail car needs to be strong enough to pull an entire train, since you don't know when it's going to be at the front. A lot of wasted weight for the ones at the back. Use the weight savings to put motors and batteries in each car. Then they only have to move themselves. If you want to put all the batteries in one car, that's fine. But include at least a small one in each car. When they get to a rail yard they can detach and drive themselves to wherever they need to be. Saves a lot of time instead of yard engines and humping the cars. Either you don't need an engine, or you only need one for control and safety purposes.

They have run into a problem, however. They can't seem to find the parts that can handle the high levels of power needed to charge vehicles enough while they are in motion. It would have to be a material that's not only weatherproof but able to withstand high voltage and heat from the passing vehicles."

You probably don't see the harm b/c you aren't black. You don't think you could come up with another term rather than "master" and "slave"? Surely, you can see that using the term "slave" for anything is a pretty poor choice. Do you see the harm if we renamed the "masters" to "husbands" and "slaves" to "wives"? Surely that would go over well, "In this database, the husband tells the wife what to do and when the wife processes the query, she provides it back to the husband. Then the wife process terminates."

Try putting yourself in someone else's shoes for a second "Mr. Pretty Liberal Guy".