By Gever Tulley with Julie Spiegler
Squash a Penny on a Train Track
Leverage the force of a locomotive.
1. Pick a location. Find a length of track that
is very straight — you want to be able to see
and hear the train coming from a long way
away. The best location is next to an automated crossing gate — the bells will warn you
when a train is coming.
2. Pick a moment. Check the schedule for
a gap of at least 15 minutes between trains.
Not all train traffic is scheduled, so you must
still wait for a time when you can neither see
nor hear any trains or crossing bells.
3. Place the penny. Tape the penny to the
top of the rail, to prevent the vibration of the
approaching train from shaking the penny
off the rail. If there’s a bright, shiny part of the
rail, tape the penny there; that’s where the
train makes the best contact with the rail.
WARNING: Because of the unfamiliar size of train
engines, our brains don’t accurately judge their distance
and speed. If you see or hear a train, assume that it’s a
danger and move to a safe distance immediately. Also,
coins may squirt out from under train wheels, so stand at
least 30 feet away from where you placed your penny.
4. Stand back and wait. Stand at least 30
feet away from all tracks, and wait for a train
to pass. If the tape doesn’t hold the penny in
place, it may come flying out at high velocity.
Pennies or other coins
Active train track
5. Find the penny. After the train passes,
and you can neither see nor hear any trains
or crossing bells, find the squashed penny.
Be careful, it may still be hot from being
squashed. Get away from the track as soon
as you have your penny.
Trains have no steering wheel.
The faster you want a train to go, the smoother the
track has to be. If the pieces of the track are bolted
together with plates, then only slow trains use it;
if they’re welded into a continuous piece of rail, the
track is probably designed for faster trains.
While a coin has never derailed a train, more than
one person has been injured putting coins on a rail.
Usually, it’s because they accidentally stand on
another track while waiting, and a train comes
down that other track and hits them.
Using the tape, it may be possible to get two
different types of coins to squash together.
Preparing them by sanding their surfaces will
increase the chances of a good metallurgical
bond. To ensure that you don’t harm the train
or the track, never put anything larger than a
coin or two on the tracks. ;
Excerpted from Fifty Dangerous Things (You Should Let
Your Children Do) by Gever Tulley with Julie Spiegler (fifty
dangerousthings.com). Gever is co-founder of Brightworks,
a new K– 12 school in San Francisco ( sfbrightworks.org).
166 Make: makezine.com/27