B&O 1957 1946 As described in the August 1946 version of the AAR publication "American Railway Signaling Principles and Practices", chapter II. 20092010JMRI DickBronson dick@rr-cirkits.com BobJacobsen jake@physics.berkeley.edu 1 2009-12-21 RGJ Initial version 1.1 2009-12-27 DB, RGJ Fix consistency, more aspects 2 2010-01-01 DB More appearances 2.1 2010-01-01 RGJ Add author and revision info 2.2 2010-01-11 DB Typo Correction 2.3 2011-06-23 DB Add speed and route information 2.4 2011-12-06 KC Normalize all aspect names to not have hyphens Clear Alt Rule 281-alt Proceed Page 42 Unofficial Rule and Aspect Name to allow for optional appearance Normal Normal Normal Clear Rule 281 Proceed Page 42 Normal Normal Normal Advance Approach Medium Rule 281A Proceed approaching second signal at medium speed Page 42 Normal Limited Normal Approach Limited Rule 281B Proceed approaching next signal at limited speed Page 43 Normal Limited Limited Clear Rule 281C Proceed; limited speed within interlocking limits Page 43 Limited Normal Diverging Approach Medium Rule 282 Proceed approaching next signal at medium speed Page 44 Limited Medium Normal Advance Approach Rule 282A Proceed preparing to stop at second signal Page 44 Normal Medium Normal Medium Clear Rule 283 Proceed; medium speed within interlocking limits Page 45 Medium Normal Diverging Medium Advance Approach Rule 283A Proceed preparing to stop at second signal; medium speed within interlocking limits Page 45 Medium Limited Diverging Medium Approach Slow Rule 283B Proceed at medium speed approaching next signal at slow speed Page 46 Medium Slow Approach Slow Rule 284 Proceed approaching next signal at slow speed. Train exceeding medium speed must at once reduce to that speed. Page 46 Medium Slow Normal Approach Rule 285 Proceed preparing to stop at next signal. Train exceeding medium speed must at once reduce to that speed. Page 47 Medium Slow Normal Medium Approach Rule 286 Proceed at medium speed preparing to stop at next signal Page 47 Medium Slow Normal Slow Clear Rule 287 Proceed; slow speed within interlocking limits. Page 48 Slow Normal Diverging Slow Approach Rule 288 Proceed preparing to stop at next signal; slow speed within interlocking limits. Page 48 Slow Slow Diverging Permissive Rule 289 Block occupied; proceed prepared to stop short of train ahead. Page 49 Stop Stop Either Permissive Medium Rule 289-medium Block occupied; proceed prepared to stop short of train ahead on medium speed route. Page 49 Unofficial Rule and Aspect Name to allow for optional appearance Stop Stop Either Restricting Rule 290 Proceed at restricted speed. Page 49 Restricted Restricted Either Stop and Proceed Rule 291 Stop; then proceed at restricted speed. Page 50 Stop Stop Either Stop and Proceed Medium Rule 291-medium Stop; then proceed at restricted speed on medium speed route. Page 50 Unofficial Rule and Aspect Name to allow for optional appearance Stop Stop Either Stop Rule 292 Stop. Page 50 Stop Stop Either