>>1209994>Can you clarify if that means a combination of short blocks and low line speed, or just short blocks?Well, top speed was limited to 35 mph (58 km/h), but I guess the concept can be extrapolated, in fact modern "dynamic" or "distance-based" systems or whatever you wanna call them like ERTMS, which signal the train according to the distance from the preceding train follow the same concept.
>The lengths of the track circuits in the automatic territory on the bridge range from 370 ft. on the 3 per cent ascending grades to 500 ft. on the 3 per cent descending grades, except approaching San Francisco, where 250-ft. track circuits are used in order to obtain headway.>A distinctive feature of the installation is that a train occupying any one track circuit automatically establishes three control areas or speed zones to the rear. The entering end of each of the respective restrictingspeed zones is far enough in the rear of the occupied track circuit to permit a motorman of a following train, by use of the service application of brakes, to reduce the train speed in each successive zone
sauce and further reading:
https://www.ekeving.se/ext/US/rt/BayBridge_RS_1939-5.pdfSo it's essentially a distance-based system liek modern HS systems, except it uses a lot of short block sections. This system was implemented way back in 1939 with surprisingly rudimentary tech. Also, at the San Francisco terminal what happened was exactly what that other anon described: The track formed a loop (so all tracks in the terminal went in the same direction), and the arriving trains with very short headways between them would "spread out" onto the various tracks. There were no other shared stations, on the other end the lines would start branching out before reaching the next stations. This system had a headway of 63,5 seconds at 35 mph speed.
