Here is the limit of rollingstock relevance here: with 20 Acela Trainsets, Amtrak has a problem deploying enough capacity at peak times. They've been able to squeeze out one super-express run and still support the rest of the schedule. If there are 10 hours of bi-directional hourly "peak" per day, there are 20 peak trains per day (WAS-NYP). Squeezing in an extra round trip brings that to 22 peak trains per day, an increase of 10% in peak capacity. 10% growth in capacity should be easily absorbed (I still think It'd be easier to absorb NYP-PHL-WAS, but it isn't like they've ruled that out by starting with NYP-WAS and seeing if things grow & rebalance).
Recall too, that Amtrak thought that a 25% growth in capacity on Acela (going from 6 coaches to 8 on each train) would have been absorbed successfully by the market, so 10%, targeted at a peak demand time, should be an economic win.
Meanwhile, 28 Avelia Liberty trainsets (a 40% growth) which each have 33% more seats, mean that Amtrak thinks it can profitably deploy a 1.4x1.3 = 1.86...an 86% increase in capacity is coming. If you think the NEC can "win" with 86% more capacity, there's every reason to believe it can fill 10% more peak capacity.
But what if it can't actually absorb all that growth that quickly? Well, just about the worst time to say "we might need the Acela 1s" would be in the first 10 years of Avelia service.
So there are only two scenarios here:
- Either the NYP-WAS can absorb an 80% increase in Acela capacity, in which case filling a 10% increase should be easy (this thread), and, if Avelia is doing that well, they'll know in time to order more (in which case: Acela 1s are irrelevant)
OR
- The NYP-WAS cannot absorb an 80% increase in Acela capacity, in which case the Acela 1s are a double-albatross (and double irrelevant)
And, if this were a different thread, I'd note that both the Avelia and Brightline/Midwest assembly lines are all tooled up and ready to crank out modern, standard fleet additions should the need arise.
"Trying to solve congestion by making roadways wider is like trying to solve obesity by buying bigger pants."--Charles Marohn