I believe the first run of a GP40P-2 in commute service was on the first train out of the new 4th and Townsend station. Correct me if I'm wrong, but I think they introduced the three GP40P-2s into commute service on the exact when the new SF station opened and a GP40P-2 never operated into the old 3rd and Townsend station.

My recollection is that the first commute run of that type was the newly painted Bicentennial unit, 3197, on train 110 at 6:10am on June 18. That being the first revenue train out of 4th & Townsend.

In pre-Push Pull days, engine utilization wasn't as efficient, of course. They had to uncouple, back to the engine terminal, be turned (turntable in San Jose; wye in San Francisco or sent to Bayshore for servicing). So it took 21 units a day to run the then 22-commute trains each way. They had 10 SDP45s, and 11 commute GP9s. That left no room for maintenance or spares. SP tried the SD9s, but they never performed very well. They also trialed a frieght GP35 on commute trains around 1972 (during the summer when steam heat wasn't needed). That worked somewhat better so they decided to order a passenger version of the GP40-2s (3197-3199) to give a total of 24 commute units - 21 needed each day, plus three spares. The SD9s were still used occasionally.

My recollection was also what another person posted. They used the GP40P-2s in frieght service for almost a year after they were built for some kind of tax purpose. 3197 was in the grey and scarlet paint then, before it was painted in the bicentenial paint for commute operations.