YOUTLDR

Why Do Escalator Steps Have Teeth?

Veritasium

YouTLDR SummaryAuto transcript

Escalator steps have teeth to interlock with a comb plate at the top and bottom. This prevents items from getting caught and allows for a smoother transition off the moving stairs.

  • ⚙️ The comb plate lifts items caught in the grooves, preventing them from being pulled into the machinery.
  • ⚠️ Early escalators had smooth steps, creating dangerous gaps that snagged clothing and shoelaces.
  • 🚶 The convention of standing on the right and walking on the left originated from a triangular shunt system designed to guide passengers off safely.
  • 🔄 Modern escalators use a system of tracks and wheels to keep steps level on the incline and flip them upside down for the return journey.
  • ⚡ Downward escalators can act as generators, using regenerative braking to produce electricity from passenger weight when busy.

A close-up, angled view of escalator steps with yellow accents, with a magnified inset showing the interlocking teeth.