20092010JMRI DickBronson PaulBender 1 2010-01-01 DB Initial version 2 2010-01-12 PAB Adapted from NYCS-1937 3 2013-7-9 PAB Add aspect mapping 4 2013-7-9 PAB Add signal icons 5 2019-03-17 PAB fix image links SLSF Double searchlight grade signal As described in the July 1978 Revision of the St. Louis San Francisco Railway Company publication "RULES for the Maintenance of way and Structures" effective July 1,1973, chapter titled Description of Signals. As noted in the source material, these rules are rules of the Frisco Transportation department. Appearances for a two-searchlight signal head with grade marker (G) and number plate Clear green red Rule 281 ../../../resources/icons/smallschematics/aspects/SLSF-1973/SL-2-high/rule-281.gif Advance Approach yellow yellow Rule 282 ../../../resources/icons/smallschematics/aspects/SLSF-1973/SL-2-high/rule-282.gif Approach Medium yellow green Rule 284 ../../../resources/icons/smallschematics/aspects/SLSF-1973/SL-2-high/rule-284.gif Approach yellow red Rule 285 ../../../resources/icons/smallschematics/aspects/SLSF-1973/SL-2-high/rule-285.gif Diverging Clear red green Rule 286 ../../../resources/icons/smallschematics/aspects/SLSF-1973/SL-2-high/rule-286.gif Diverging Approach red yellow Rule 287 ../../../resources/icons/smallschematics/aspects/SLSF-1973/SL-2-high/rule-287.gif Restricting lunar red Rule 288 ../../../resources/icons/smallschematics/aspects/SLSF-1973/SL-2-high/rule-288-a.gif Grade red red Rule 289 ../../../resources/icons/smallschematics/aspects/SLSF-1973/SL-2-high/rule-289.gif Grade Grade Stop Approach Stop and Proceed Approach Grade Approach Restricting Approach Diverging Approach Approach Medium Diverging Clear Approach Medium Approach Advance Approach Approach Medium Clear Approach Limited Clear Advance Approach Clear Clear Clear