Can a Penny Derail a Train? The Myth, the Science, and the Truth Behind a Classic Question

Introduction

At some point in life, almost everyone hears the question whispered with a mix of curiosity and mischief: can a penny derail a train? It sounds like something kids dare each other to test, or a plot point straight out of a cartoon. After all, how could something so tiny challenge a roaring, multi-ton steel monster barreling down the tracks?

Yet here we are, still asking it. Still wondering. Still half-expecting some shocking “yes” that flips everything we know about physics upside down.

So let’s slow things down for a moment. With trains rumbling in the distance and a penny spinning between our fingers, it’s time to separate myth from reality. Along the way, we’ll dip into physics, history, urban legends, and real-world rail safety. Buckle up — or rather, hold onto your seat — because this question goes deeper than it looks.

Where Did the Penny-on-the-Track Myth Come From?

A Childhood Dare That Refused to Die

Long before viral videos and social media experiments, kids were daring each other near train tracks. The idea was simple: place a penny on the rail, wait for the train, and come back later to see what happened. Usually, the coin came back flattened, stretched, or warped into a strange souvenir.

That visual alone was powerful. If a train could squash a penny like that, surely the penny must’ve fought back a little, right?

Over time, the myth evolved. The question shifted from “what happens to the penny?” to the far more dramatic “can a penny derail a train?” And just like that, a legend was born.

Why the Myth Stuck Around

Urban legends survive when they’re simple, repeatable, and just believable enough. This one checks all the boxes. A penny feels small, but metal is metal. Trains are powerful, but physics can be weird. Toss in a lack of firsthand experience, and suddenly the idea doesn’t sound completely impossible.

But as tempting as the myth is, reality has a habit of crashing the party.

Understanding the Sheer Power of a Train

How Heavy Is a Train, Really?

Let’s talk numbers, because feelings don’t derail trains — physics does.

A single freight train can weigh anywhere from several thousand to tens of thousands of tons. Each wheel alone can bear loads exceeding tens of thousands of pounds. And that weight isn’t evenly distributed across the rail; it’s concentrated where steel meets steel.

A penny, by comparison, weighs about 2.5 grams. That’s less than a paperclip having a bad day.

Momentum Doesn’t Care About Pocket Change

Even at modest speeds, a train carries massive momentum. Once it’s moving, stopping it takes miles, not meters. That forward force laughs in the face of small obstacles.

So when people ask can a penny derail a train, they’re really asking whether a tiny object can disrupt an overwhelming amount of mass and momentum. Spoiler alert: physics isn’t sentimental.

What Actually Happens When a Penny Meets a Train?

The Penny Loses. Every Time.

When a penny is placed on the rail and a train passes over it, one of two things happens. Either the penny gets crushed flat, or it gets flung away at high speed, sometimes barely touched at all.

The train doesn’t notice. There’s no wobble. No dramatic screech. No heroic struggle between coin and machine. The penny simply gives up.

Why the Rail Shape Matters

Train rails aren’t flat like roads. They have a rounded head designed to guide wheels smoothly. Often, the wheel doesn’t even make full contact with the penny. Instead, the coin is pushed aside or squashed harmlessly.

So while the penny might look dramatically transformed afterward, that’s a result of localized pressure, not a sign of danger to the train.

Can a Penny Derail a Train? The Scientific Answer

Short Answer? No. Long Answer? Still No.

Let’s be crystal clear: can a penny derail a train? No. Not in real-world conditions. Not on modern railways. Not even close.

For a derailment to occur, something must significantly alter the wheel’s path or lift it off the rail. That requires forces far beyond what a small coin can provide.

What Can Derail a Train?

While a penny won’t do the trick, derailments do happen. They’re usually caused by serious issues like:

• Broken or misaligned tracks
• Large debris such as fallen trees or vehicles
• Mechanical failures in wheels or axles
• Excessive speed on curves
• Structural damage from weather or collisions

Notice what’s missing? Spare change.

The Physics Behind the Myth

Pressure vs Force

People often confuse pressure with force. A train exerts enormous force due to its mass, but that force spread across steel rails remains stable. The penny experiences extreme pressure because that force is concentrated on a tiny area.

The result? The penny deforms, not the train.

Newton Isn’t Impressed by Pennies

Newton’s laws of motion don’t bend for folklore. An object at rest stays at rest unless acted upon by a significant force. A penny doesn’t provide enough resistance to act back on a moving train in any meaningful way.

In other words, the laws of physics shrug and move on.

Real Experiments and Observations

What Controlled Tests Show

Engineers, rail workers, and science educators have tested this question countless times. The outcome is always the same. The train rolls on. The penny becomes art.

Some tests even show that the penny barely gets touched, proving how minimal its interaction with the wheel truly is.

Why Videos Can Be Misleading

Online videos often dramatize the moment, slowing footage or zooming in on the coin. While entertaining, they don’t reflect the scale of forces involved. A flattened penny looks impressive, but it’s misleading without context.

The Safety Side of the Story

Why You Should Never Try This

Even though a penny can’t derail a train, placing objects on tracks is dangerous and illegal in many places. Trains move fast, quietly, and unpredictably. Standing near tracks puts lives at risk, and not just your own.

Railways are not science labs. They’re industrial systems designed for transport, not experiments.

The Real Danger Isn’t the Penny

Ironically, the real hazard isn’t the coin — it’s the person placing it. Trains can’t stop quickly, and engineers can’t always see obstacles in time. What starts as curiosity can end in tragedy.

Why This Question Refuses to Go Away

Humans Love David vs Goliath Stories

There’s something irresistible about the idea of a tiny object challenging a massive force. It’s the same reason we love underdog stories and impossible victories.

The question can a penny derail a train taps into that instinct, even when logic says otherwise.

Simple Questions Feel Safer Than Complex Answers

It’s easier to ask a playful “what if?” than to dive into engineering textbooks. Myths thrive in that gap, living comfortably between curiosity and ignorance.

FAQs

Can a penny derail a train under any circumstances?

No, a penny does not have the mass, strength, or structure needed to derail a train.

Why does the penny get flattened so dramatically?

Because the force exerted by the train is concentrated over a very small area, deforming the coin.

Can other small objects derail a train?

Only objects large and solid enough to lift wheels off the rail or damage the track pose a derailment risk.

Is it illegal to put objects on train tracks?

In many regions, yes. It’s considered trespassing or interference with rail operations.

Do trains ever notice hitting small objects?

Generally, no. Engineers often don’t feel or hear anything at all.

Conclusion

So, after peeling back the layers, crunching the physics, and busting the myth wide open, the answer is clear. Can a penny derail a train? No, not even on its best day.

What the penny can do is spark curiosity, fuel storytelling, and remind us how easily myths take hold when science stays silent. The real lesson isn’t about coins or trains, but about questioning what we hear and digging a little deeper before believing it.

Next time someone asks the question with a grin, you’ll know the truth. And honestly, that knowledge is worth far more than a flattened penny could ever be.