Along with the connecting rods (the English called them "cranks"), the main rod transmits the mechanical force of the piston to one driver and subsequently through the other rods to the remaining drivers—giving rise to the term "coupled locomotive." The main rod attaches to the crosshead and to the crank pin on the main axle. This changes back-and-forward (lateral) motion into rotary motion and turns the main driving axles and wheels.
Quick facts
No light-weights here
First use in England
Operatic origins