Atchison, Topeka and Santa Fe System theme from 1989 rulebook on Railroad Signals of the US website based on SpDrS60 theme. The following signal masts are supported:-

Prefix	Mast type
	Single head mast automatic
1a_	Single head mast standard head aspect numbers
1_	Single head mast unified ATSF aspect numbers
2_	Twin head mast unified ATSF aspect numbers

Automatic aspect numbers
-r	R242	red
-y	R236	yellow
-g	R230	green
-w	R240	flashing red
-b	-	unlit


Standard head aspect numbers
-0	R241/42	red
-1	R236	yellow
-2	R230	green
-4	R240	flashing red
-5	R234	flashing yellow
-8	-	unlit

Unified ATSF aspect numbers
-0	R241/42	red / (red)
-1	R241/42	red / (dark)
-2	R240	(red) / flashing red
-3	R240	red / lunar
-4	R238	red / yellow
-5	R238	red / flashing yellow
-6	R237	red / green
-7	R236	yellow / (red)
-8	R236/43	yellow / (dark)
-9	R235	yellow / lunar
-10	R234	flashing yellow / (red)
-11	R234	yellow / yellow
-12	R232	yellow / green
-13	R231	yellow / flashing green
-14	R230	green / (red)
-15	R230	green / (dark)
-16	-	unlit
