A 3-engine Cordership is a c/12 diagonalspaceship, specifically a Cordership consisting of three switch engines. Shown in the infobox is the first example that was discovered by Paul Tooke on January 12, 2004. It was the only known Cordership of this type until September 15, 2020, when wwei23 discovered several new ones with different timings between three engines. The rest of this article only deals with Tooke's original 3-engine Cordership.
In 2009, Dave Greene discovered a glider synthesis for upgrading a switch engine to a wing, which can be repeated to form the complete Cordership. Adam P. Goucher then built a Herschelconduit to convert a glider into a 3-engine Cordership.