One of the reasons Connecticut financed its group of SPVs was to cover the New Haven-Springfield trains that connected with the Northeast Corridor. This one is at Windsor Locks
Fully 1/3 of Amtrak's "Spivvies" comprise train 473 this day. Maybe there is "safety in numbers", in case one craps out, the other three can handle the load.
Pair of SPV's pause at the Windsor Locks "Amshack" as train 450.