Originally Posted by lawfin
Let me preface with the fact that I am in no way a transit professional, engineer etc. Why would electrification be required....pollution, fuel costs? I am curious.
I imagine one of the barriers to increasing frequency..... besides the institutional inertia of an organization that has historically looked to ever expanding into suburbia as its method of growth.....is that there may be capacity constraints at the DT terminus and other "crossovers" where trains that don't complete a run can be rerouted back the other direction.
I don't know the lingo so I am trying to describe as best I can.
It really has little to do with pollution or fuel cost - although those would be side benefits. To best understand why electrified trains serving lines with short intervals between stations just look at the L, and imagine if the propulsion was diesel instead of electricity.
Or for another example imagine a diesel locomotive hauled train of 6 carriages, nearly fully loaded. You've seen a train like this accelerate from zero mph. It is painfully slow, not to mention loud. Most of Metra's operations are just this. Now imagine an electrically driven 6 carriage EMU train leaving a station fully loaded - quick acceleration, low noise.
Diesel propulsion of trains = low starting torque and long acceleration time. Electric propulsion of trains = high starting torque and fast acceleration time.
As a side note, I'd love to see those new Stadler KISS double deck EMU's running on newly electrified Metra lines. I can dream...