A Penny on the Rail

Quite innocently you can start something that you don't intend. Visiting an uncle in Raleigh when I was a child, I went walking with my even younger brother. We were excited to find a train track that ran through town. When a train came, cars had to stop because there were. no underpasses.

I guess we had been told you could put a penny on a rail and a passing train would squash it. We had a penny. At that time it was 100% copper with a design featuring some sheaves of wheat. (This was before Lincoln’s face.) We put the penny on the track and waited. A freight train came by. After the caboose had passed, we found an oddly shaped thin sheet of copper.

So far, so good. Then we noticed that some rails were separated by a gap and fastened with insulated bolts. We realized that when a set of wheels ran over this gap it would close an electrical circuit and that this possible flow of current might be connected to the signals nearby. We’d noticed that when a train passed, the signal turned red. Now we had a hypothesis about why.

When we bent the thin copper over the insulator and connected the two rails, the signal turned red. We were delighted to have figured this out. Before we could remove the copper, a train stopped a few blocks away. When we grasped the power of what we’d done, we were frightened and ran away.

During rush hour the long train stood there, blocking vehicle traffic. I hope some drivers made detours and got home for dinner, but it was a mess. I guess someone must have eventually discovered the copper sheet or maybe the train went ahead very cautiously.

We had just been playing, but apart from the working of the signal system, my brother and I learned that acts of curiosity could have unintended consequences. (Also, after college my brother went into Information Technology.)