Caught on Camera: New CSX Signal Rules in Action

A few months ago I posted about CSX's two new "Canadian" style signal rules, 281E Limited Approach Medium and 281F Limited Approach Limited, to augment its existing Rule 283A Medium Approach Medium and 283B Medium Approach Slow. Although established in 2024, I had not been expecting to catch one in the wild for some time as railroads tend to bend over backwards to avoid signal modifications if they can be avoided. Sightings of the new signal indications had mostly been in former Seaboard System territory in Georgia and Florida. Therefore you can imagine my surprise when, after stepping off Amtrak Empire Service Train 281, I saw a Rule 281D Limited Approach upgrade to Rule 281F, Limited Approach Limited at Chicago Line interlocking CP-292.

Now Rule 281D Limited Approach has been present on the Seaboard main lines for several decades, and although it is an odd duck, by seeming to authorize Limited speed up to a stop signal instead of Medium, this could have been present as part of the general Chicago Line re-signaling of the 2010's. The Rule 281F indication has to have been added since September 2024  so that is evidence of more system-wide changes on the part of CSX. 

As to why CSX is retrofitting existing interlockings as opposed to using 281E/F only in new projects my guess would be this is a downstream cost of PTC speed enforcement. Not so much in the sense that crews would "cheat" when 283A Medium Approach Medium was displayed for Limited Speed turnouts (although they probably did), but PTC's conservative braking curves could be raising the cost of signal indications that leave speed on the table.