The Bennie Railplane is like a train that runs on an elevated track. Imagine if you had a toy train set, but instead of putting the tracks on the ground, you put them up high in the air on big poles. That's basically what the Bennie Railplane was.
It was invented by an engineer named George Bennie in the 1920s, and he thought it would be a good way to get people and goods around quickly and efficiently. The Railplane had a special carriage that glided along the top of the elevated track, kind of like a roller coaster.
But there were some problems with the Railplane. For one thing, it was expensive to build the elevated track, and it took up a lot of space. Plus, it was hard to turn corners, so you couldn't really use it to go to places that weren't in a straight line. And it was noisy and bumpy, so people didn't really like riding on it.
In the end, the Bennie Railplane didn't really catch on and only one was ever built. But it was an interesting idea and showed that people were trying to find new and better ways to get around.