The 4-engine Cordership is a diagonal c/12 spaceship that was discovered by David Bell on July 9, 2005. It is the smallest known Cordership in terms of its minimum population of 134 cells. David Bell used this spaceship to create a small sawtooth, sawtooth 260.
A slight modification of this Cordership that is asymmetric, with a minimum population of 136 cells, is also quite well-known and displayed below.
In November 2014 Michael Simkin discovered an alternate 4-engine Cordership, with temporally independent front and back halves -- the last two switch engines can be delayed by any number of ticks relative to the front.
The 136-cell variant of the 4-engine Cordership.RLE: here
- ↑ Dave Greene (August 10, 2005). "New Sawtooth Patterns". Retrieved on April 21, 2017.
- ↑ Michael Simkin (November 5, 2014). "Four engine extendable Cordership". Retrieved on April 21, 2017.