Why was the Chafee Subdivision signaled with Centralized Traffic Control (CTC) while the St. Louis Subdivision was signaled with Automatic Block Signals (ABS)? More traffic? Run out of money? Glenn Fisher
The first question should be: Why did the St. Louis Subdivision have OBS between Southeastern Junction and Marquette, MO, while the rest of the St. Louis Sub and the Chaffee Subdivision operate as a dark railroad?
Employee Time Table (ETT) number 42, 9/27/1959, shows ABS from SE Jct. to Nash, MO and CTC from there to Turrell, AR. Glenn
I do not know why the 1959 ETT lacks this information, but previous and latter ETTs note that the St. Louis Subdivision between Southeastern Jct. and Marquette operated with OBS or ABS (Rule 510a), which is Frisco speak for OBS.
Yes, the Frisco employed both APBS and OBS, both of which a variations of an Automatic Block Signal system. There are several discussion on the site. Search for OBS or APBS.
Nash, MO - Turrell, AR centralized traffic control (CTC) was installed in 1954. Southeastern Jct. (Lindenwood) - Nash, MO CTC was begun in 1978, in service to Neely's in March 1979, and completed to Nash June 1979. There was always more traffic on the south end. Even today, there is a lot of traffic out of Blytheville, AR. Roger
