The World's Dirtiest Engine is the ninth episode of Season 3

The World's Dirtiest Engine
Season 3, Episode 9
Air date October 22, 2011
Written by HenryDashPaxton3000
Episode guide
Station Trouble
Percy & The Truck

"Call yourself shiny get out of here you piece of rubbish"

Spencer upon seeing Saturn


It is a contest for the cleanest engine as said by Spencer. Saturn wants to win but see has a very busy day. She delivers her coal to the sheds and goes to collect milk. She sees Paxton broken down and decides to help him. Luckily for her Diesel offers to deliver it for her. She is now covered in smoke and ash. She goes for slate and accidentely goes under the hopper. Mavis tells her to just go to the washdown. But she doesn't. She is finally done until a workman tells her that the Inspecters boat is stuck. She pulls it but gets covered with sea water and mud. She quickly hides and comes back when she is ready. Spencer laughs at her for not being shiny. But looks around and all the engines are dirty and it was a Really Useful Contest and Saturn has won for doing many jobs.


  • Thomas
  • Percy
  • Toby
  • Saturn
  • Spencer
  • Sir Topham Hatt
  • Stanley (cameo)
  • Rosie (cameo)
  • Cranky (cameo)


  • The episode is named after "The Strongest Engine in the World" from the Thomas The Tank Engine & Friends series.
  • In a deleted scene it shows how Spencer got the news of the contest.