Doktor No wrote: ↑Tue Feb 06, 2024 2:02 pm
The square signals denote SEABOARD signals.
That's just not the right way to think about it. The title of the rules section "denotes" what type of signals they're talking about. The graphics don't matter beyond the aspects depicted. It's going to be easier/faster/cheaper for whomever updates the rulebook to copy/paste existing graphics than to try and create new ones faithful to the existing ones.
The "Seaboard" section, called Standard signals:
The "Chessie" section:
Copy and Pasting:
The rule number clearly indicates these aspects are in Chessie territory. It doesn't matter what style the graphics are in. CSX has added some traditionally-Seaboard (or traditional speed signaling) signal aspects to Chessie territory. Both Y/Y/D and Y/R/G are acceptable aspects for
Approach Slow in Chessie territory. You can try and call them "Seaboard signals" if you want, but they are in the Chessie section!
David Collins wrote: ↑Tue Feb 06, 2024 3:30 pm
I gotta ask, I don’t know much about signaling so humor me, why do railroads use multiple signal books/rules on their entire system?
In addition to
DaveO's astute reply, I'd like to add that changing the actual signals is just part of the cost. Retraining the crews to understand them also costs money, both in time spent in class instruction, time spent away from performing revenue service, and inevitable mishaps that occur from the changes.