We just learned about the Brake Shoe.
Another part of a steam locomotive is a Coupling Rod or Side Rod.
When the steam engine uses its power to turn the wheel of a steam locomotive, it is usually only turning one wheel.
That wheel is connected to the other wheels by a big metal rod called the coupling rod.
So when the driving wheel is turned, it makes all the wheels turn and spin at the same speed so it makes the train more stable and gives it more power.
(from: wikipedia - coupling rod)
Kid Facts - Blast from the past: Air Gap
