I fully expected Amtrak would buy more of these locomotives for themselves.
Which brings up the following question, is 75 enough?
To answer that's let's look at Amtrak road locomotives roster now.
Per
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P42 (1-201) 185 active
P40 (800-843) 13 active
P32AC-DM (700-717) 18 active (refurbishing program underway)
P32-8 (500-519) 18 active
F59PHI (450-470) and (2001-2015) 11 and 15 active (recently sold 21 of these to METRA, i'm assuming 450-470).
Will not include separately maintained NCDOT locomotives.
Old road diesels totals up to 249
Siemens SC-44s orders to date:
IDOT (4601-4633) 33
CDOT (2101-2120) 20
WDOT (1400-1407) 8
Subtotal 61
New today 75
Total orders to date 136
So we are still short 113 locomotives for a one per one replacement.
One could argue the 18 P32-8 (Pepsi cans) may not be replaced soon because they are often used for switching duties, and the 18 P32AC-DM may not as well having been recently refurbished. I'm thinking NYDOT will eventually be purchasing most of the replacements for these Dual Mode locomotives for Empire services.
So subtracting that 36 from 113 leaves Amtrak 77 locomotives short. So some P42s will probably be around for some time to come.