train wheels
- steelCarbon-hardened iron alloy
- tracksMarks showing passage
- rollingTurning over repeatedly
- axleShaft for wheel rotation
- locomotiveRailway pulling machine
cargo · clickety-clack · flanges · rails · iron · sparks · screech · rotation · freight · bogie · coupling · grinding · momentum · metal · station · platform · speed · brake
train wheelsboat hull
Vessel's main body structure
ship propeller · legs · treads · tank tracks