Greetings everyone,
In brief:
ATSF and C&S trains, from the years 1900 to 1995 (the year of the big merger), between Denver and Pueblo CO, operated under Joint Operating Agreements. Under the JOAs the C&S was a tennant on the ATSF line, but the line was operated as a single
line with each company providing equipment in the proportion of the tonnage, passenger numbers of the previous month.
(Revenue and costs of running the line were shared according to the agreed formulae.)
Locomotives and equipment, including way cars/ cabooses, were drawn from this pool. It became not unusual for:
ATSF and C&S freight trains to combine for operational reasons.
ATSF way cars on C&S trains and vice versa.
The allocation of crews is less certain. But the mechanism certainly changed over time.
It is likely, initially, that C&S crews manned the C&S equipment. It is possible that the crew pools in Denver were combined: evidence is lacking.
By the 1920s bidding for the Joint Line (C&S Southern division) freights became less attractive for C&S men and the pool diminished: ATSF men took up the slack. Passenger work remained "plum" jobs and were bid for strongly.
C&S men did end up on ATSF trains; often working along side ATSF crew.
At some point, it appears, the ASTF local unions exerted pressure and the C&S men gradually yielded all positions on the line. It seems that the expedient was to prevent new C&S joint the pools.
Hol Wagner is best placed to provide more informtion.
Mark Sellars