B&O 1980 1980 As described in the Chessie System 1980 Rule Book. 2010 JMRI Greg McCartney gpmccartney@gmail.com 1 2016-07-28 GPM Initial version 2 2019-09-26 GPM Corrected the comments on the use of Stop and Proceed Medium. 3 2020-07-09 GM Added masts with short block in their name to allow for Approach Medium aspect in advance of Approach for use in areas where there is short braking distance prior to the next signal 4 2020-08-06 GM Changed all of the route fields from normal or diverging to either to make the system rely soley on block and turnout speeds for aspect selection. This will bring the system in line with the B&O 2009 system. Clear Rule B-281 Proceed Page 128 Normal Normal Either 15 Approach Limited Rule B-282 Proceed approaching next signal at not exceeding limited speed. Page 129 Signal is identical to Approach Medium except for the addition of a triangle flag on signal mast Normal Limited Either 14 Approach Medium Rule B-282-A Proceed approaching next signal at not exceeding medium speed. Page 129 Normal Medium Either 12 Limited Clear Rule B-283 Limited speed through crossovers, turnouts, sidings, interlocking limits and over power switches: then proceed at maximum authorized speed. Page 130 Signal is identical to Medium Clear except for the addition of a triangle flag on signal mast Limited Normal Either 13 Medium Clear Rule B-283-A Medium speed through crossovers, turnouts, sidings, interlocking limits and over power switches: then proceed at maximum authorized speed. Page 130 Medium Normal Either 11 Medium Approach Medium Rule B-283-B Proceed at not exceeding medium speed approaching next signal at not exceeding medium speed. Page 131 Medium Medium Either 10 Medium Approach Slow Rule B-283-C Proceed at not exceeding medium speed approaching next signal at not exceeding slow speed. Page 131 Medium Slow Either 9 Approach Slow Rule B-284 Proceed approaching next signal at slow speed. Train or engine exceeding medium speed when indication is seen must take action at once to reduce to medium speed or slower, if necessary. Page 132 Normal Slow Either 8 Approach Rule B-285 Proceed prepared to stop at next signal. Train or engine exceeding medium speed when indication is seen must take action at once to reduce to medium speed or slower, if necessary. Page 133 Normal Slow Either 7 Medium Approach Rule B-286 Proceed at not exceeding medium speed prepared to stop at next signal. Page 134 Medium Slow Either 6 Slow Approach Slow Rule B-287 Slow speed through crossovers, turnouts, sidings, interlocking limits, and over power switches. Train or engine may then proceed at maximum authorized speed, if conditions permit, but must approach the next signal at not exceeding slow speed. Page 135 Slow Normal Either 4 Slow Approach Rule B-288 Slow speedthrough crossovers, turnouts, sidings, interlocking limits, and over power switches; then proceed at not exceeding medium speed prepared to stop at the next signal. Page 136 Slow Slow Either 3 Restricting Rule B-290 Proceed at restricted speed. Page 137 Restricted Restricted Either 2 Stop and Proceed Rule B-291 Stop; then proceed at restricted speed. Page 138 Stop Stop Normal 1 Stop and Proceed Medium Rule B-291-medium Stop; then proceed at restricted speed on medium speed route. Page 138 Stop and Proceed Medium can be substituted for Stop and Proceed when there is diverging route through an interlocking. To use, create a logix that states when the signal displays stop and proceed and the turnout is lined for the diverging route, set signal to stop and proceed medium. Stop Stop Diverging Stop Rule B-292 Stop Page 140 Stop Stop Either 0 Unlit Unlit Stop Stop Either 31