I'm not sure why you think it's an either-or proposition.
EMUs are perfectly capable of running long distances without stopping. If the fleet was large enough, and enough wire strung, there is no reason why they couldn't be used for express services as well.
Yes, locos are better suited for running between fewer stops than for many short stops because of more power, fewer axles, etc. But just because they have that disadvantage doesn't mean that EMUs automatically have the opposite disadvantage. They don't.
Dan
This is a conversation about the marginal value one gains versus the marginal cost when evaluating the two options.
I'm not trying to say EMUs have this kind of
disadvantage, but that it doesn't have unspoken advantages beyond what is already known- shorter/faster acceleration times being the key one. Perhaps you can reach higher top speeds, but as far as I'm aware it's not substantial. My point is that with the state the GO network is in, there would be no noticeable difference in service to use EMUs or electric locomotives, and it would be very expensive to get the network to such a point. At least double what we are putting in now, given how expensive both stations
and/or a full replacement fleet of EMUs would be (yes, and/or; neither of these is small or cheap, at all).
If we had a narrow stop spacing already, of say 2km per station rather than 4-5km, then yes, EMUs would be worth considering. Electric locos would perform
measurably worse by comparison. While this is a chicken-or-the-egg type of problem, we can and are fitting plenty of stations with electric locomotives, so It'll be at least 15 years before this will even become a problem.
And side factors as well, if you're not gonna buy the "we couldn't make use of them" line:
1. We have an enormous fleet of carriages ready to go. There is nowhere for us to send them, and it is a massive number of units to order as replacement.
2. Diesels will remain in operation, with those carriages anyway. Might as well be interchangeable across the network, at least for a transition period.
3. Transit dollars are finite. We can still buy EMUs- let's just do it when we need them, instead of having them turn 20 when they finally start outperforming an electric locomotive on the network.
And to be clear, I like EMUs. If we are going to electrify additional lines, like Milton, then it would be a good opportunity to buy newer, smaller trains to make our lives easier for that purpose. But GO Expansion isn't a total new slate.
Source? The 2018 IBC had the line electrified all the way until Lincolnville.
I would have to look for you, but in short, a lot has changed since this business case. It may not be relevant at all anymore for what the service plan will be. The giveaway should be that 'trains every 15 minutes' is well out the door. I am sure other members are more familiar with how different the plans are, and where those can be seen, but I will make a point of checking when I can.
This is also OK- what is clear is that the quality of service on the electrified network will be way higher than this document stated. If the 'scoping' of the project has resulted in some trimmings for later phases like dropping Centennial-Lincolnville, we can survive till then. I'd be much more concerned if an entire corridor was axed at this point. By not biting off more than we can chew, the more quickly benefits can be realized, whenever that might be...