The '''3-engine Cordership''' is a [[c/12 diagonal]] [[spaceship]] that was discovered by [[Paul Tooke]] on January 12, {{year|2004}}. Until the [[2-engine Cordership]] was found, it was the [[Cordership]] that used the fewest number of known possible [[switch engine]]s. Despite this, the [[4-engine Cordership]] is smaller in terms of minimum population (the [[2-engine Cordership]] beating both).
A '''3-engine Cordership''' is a [[c/12 diagonal]] [[spaceship]], specifically a [[Cordership]] consisting of three [[switch engine]]s. Shown in the infobox is the first example that was discovered by [[Paul Tooke]] on January 12, {{year|2004}}. It was the only known Cordership of this type until September 15, {{year|2020}}, when [[wwei23]] discovered several new ones with different timings between three engines.<ref name="post104102" /> The rest of this article only deals with Tooke's original 3-engine Cordership.
[[David Bell]] discovered in {{year|2005}} that the 3-engine Cordership can be used to turn a [[lightweight spaceship]] 90 degrees as shown below.<ref>{{LinkGoLNews|2005/06/new_compact_corderships.html|title=New Compact Corderships|date=June 18, 2005|author=Dave Greene}}</ref> It could be [[glider synthesis|constructed]] with 15 [[glider]]s, and Tooke created a [[gun]] for this spaceship only a week after its original construction (see [[3-engine Cordership gun]]). In March 2017 Luka Okanishi discovered a three-glider synthesis for a switch engine, which reduced the recipe to only 11 gliders.<ref>{{cite web|url=https://conwaylife.com/forums/viewtopic.php?f=2&t=279&p=41558#p41557 |title=Re: Thread For Your Accidental Discoveries|publisher=Luka Okanishi|date=March 12, 2017|accessdate=March 13, 2017}}</ref>
It was once the Cordership that used the fewest number of known possible [[switch engine]]s, although the [[4-engine Cordership]] is smaller in terms of minimum population. Later, both were surpassed by [[2-engine Cordership]] in 2017.
The 3-engine Cordership can easily be destroyed by three [[eater 1]]s and four [[block]]s, as shown below. This cleanup reaction was found by [[Jason Summers]].
== Reactions ==
As found by [[Jason Summers]], the 3-engine Cordership can easily be destroyed by three [[eater 1]]s and four [[block]]s, as shown to the left below. [[David Bell]] discovered in {{year|2005}} that the 3-engine Cordership can turn a [[lightweight spaceship]] 90 degrees with a [[spark]] similar to [[Twin bees shuttle spark|the one from twin bees shuttle]], as shown to the right.<ref>{{LinkGoLNews|2005/06/new_compact_corderships.html|title=New Compact Corderships|date=June 18, 2005|author=Dave Greene}}</ref>
On September 15, 2020, [[wwei23]] discovered several variant 3-engine Corderships, including one that cleans up its trailing blocks with sideways gliders, similar to a [[5-in-a-row Cordership|5-]], [[6-in-a-row Cordership|6-]], or [[7-in-a-row Cordership]].<ref>{{cite web|url=https://conwaylife.com/forums/viewtopic.php?p=104102#p104102|title=Re: Thread For Your Unsure Discoveries|publisher=wwei23|date=September 15, 2020|accessdate=September 28, 2020}}</ref>
{|
|{{EmbedViewer
|pname = 3enginecordershipeater
|position = center
|caption = 3-engine Cordership eater using eater 1s and blocks
|viewerconfig = [[ ZOOM 4 HEIGHT 450 ]]
}}
|{{EmbedViewer
|pname = 3enginecordershiplwssreflection
|position = center
|caption = 3-engine Cordership about to reflect a lightweight spaceship by 90 degrees<br>
|viewerconfig = [[ ZOOM 4 ]]
}}
|}
The spark from 3-engine Cordership can also reflect a [[glider]], which was used in the original 269-cell form of [[sawtooth 260]].
==Incremental construction==
== Synthesis and related constructions ==
[[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 Herschel conduit to convert a glider into a 3-engine Cordership.<ref>{{cite web|url=http://b3s23life.blogspot.com/2009/02/first-complete-glider-to-cordership.html |title=First complete glider-to-Cordership converter |publisher=Dave Greene |date=February 7, 2009 |accessdate=June 15, 2009}}</ref>
A 15-glider [[synthesis]] was found early on and used in several constructions, including a period-690 [[gun]] (based on [[period-690 glider gun]]) and a period-240 [[c/2 orthogonal]] [[rake]], both of which were published on January 19, {{year|2004}}.
==Image gallery==
{|
{|
|-
|{{EmbedViewer
|{{EmbedViewer
|pname = 3enginecordershipeater
|pname = 3enginecordershipgun
|position = center
|position = center
|caption = 3-engine Cordership eater using [[eater 1]]s and [[block]]s<br>
|caption = Period-690 3-engine Cordership gun by Paul Tooke<ref><tt>Patterns/Life/Guns/p690-PT-Cordership-gun.rle</tt> from [[Golly]]'s pattern collection</ref>
}}
}}
|{{EmbedViewer
|{{EmbedViewer
|pname = 3enginecordershiplwssreflection
|pname = 3enginecordershiprake
|position = center
|position = center
|caption = 3-engine Cordership about to reflect a lightweight spaceship by 90 degrees<br>
|caption = Period-240 3-engine Cordership rake by Jason Summers<ref><tt>Patterns/Life/Rakes/c2-Cordership-rake.rle</tt> from [[Golly]]'s pattern collection</ref>
}}
}}
|}
|}
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 [[Herschel]] [[conduit]] to convert a glider into a 3-engine Cordership.<ref>{{cite web|url=http://b3s23life.blogspot.com/2009/02/first-complete-glider-to-cordership.html |title=First complete glider-to-Cordership converter |publisher=Dave Greene |date=February 7, 2009 |accessdate=June 15, 2009}}</ref>
In March 2017, thanks to [[Luka Okanishi]]'s discovery of a three-glider synthesis for a switch engine, the minimal recipe for a 3-engine Cordership was reduced to {{gliders|11|brief}} gliders.
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.[1] The rest of this article only deals with Tooke's original 3-engine Cordership.
It was once the Cordership that used the fewest number of known possible switch engines, although the 4-engine Cordership is smaller in terms of minimum population. Later, both were surpassed by 2-engine Cordership in 2017.
The spark from 3-engine Cordership can also reflect a glider, which was used in the original 269-cell form of sawtooth 260.
Synthesis and related constructions
A 15-glider synthesis was found early on and used in several constructions, including a period-690 gun (based on period-690 glider gun) and a period-240 c/2 orthogonalrake, both of which were published on January 19, 2004.
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.[5]
In March 2017, thanks to Luka Okanishi's discovery of a three-glider synthesis for a switch engine, the minimal recipe for a 3-engine Cordership was reduced to 11 gliders.
