Electric does help with getting cars to run quieter and faster though. With the old diesel engines, they needed more headway because of slower cold start times so there's more frequency and can hit the speed limit faster. Electric engines have high torque and are naturally much quieter.
It's not the electric motor torque that makes the difference. Caltrain used to use traditional locomotives, you'd have a single F40PH or MP36PH at one end pulling a bunch of unpowered carriages. Those locomotives were diesel-electric though, that is the diesel is only there to act as a generator while the traction motors are electric.
The Stadler KISS units are so much faster because they're EMU's (Electric Multiple Units), that is most of the wheels in a 7-car consist are powered with their own traction motors. An F40PH makes 3000 hp (2200 kW) while a Caltrain 7-car KISS consist can put out 9400 hp (7000 kW) continuous and about 50% more than that in short duration overload mode for starting. That's the reason it accelerates so much faster.
Traditional locomotive trains are completely obsolete in any sort of commuter service with frequent stops, there's just no way for them to keep up with EMU's or even DMU's. You can't solve it by just putting bigger engines on the locomotives, you wouldn't have enough weight on the wheels to make sufficient tractive effort.
Yup not to mention that the fumes from diesel engines got into the cars so you tended to avoid the ones close to the engine. Its a HUGE qol improvement!
For now. They're replacing them with battery-electric trains that can go past Tamien. Yeah, it should just have caternaries the whole way down but you know how rail is around here -- owned by Union Pacific, and the federal government prevents municipalities from exercising eminent domain to take control of railways.
I did not know that. I checked the schedule for those when I had jury duty in Morgan Hill and it was always never the right time and/or in the wrong direction, so I had to take the bus from the Diridon station to make my jury duty appointments.
