The "oldest" and the "newest". Amtrak 29 (Capitol Limited) arrived in Chicago, Illinois on the morning of Wednesday, October 16, 2019 with P42DC 156 in the lead. This unit is painted in a tribute to the Phase I "Bloody Nose" scheme that was the first original Amtrak paint in 1971. IDTX 4622 is a Siemens Charger SC-44, part of the newest class of Amtrak operated engines under the "Amtrak Midwest" brand of state supported routes, running in "Wolverine Service" to Michigan.