Saw an interesting Amtrak train today, can anybody tell me about it?

Unfortunately I can’t give great details because I didn’t get to stop and take a close look, and I didn’t get any pics, but I’ll tell you what I know (which isn’t much).

The locomotive was an odd unit, I’m not even sure what it was. It had a long hood and a squished looking nose. Not as tall as something like a GP 38, but it resembled one, in a way. Kinda looked like a bull dog from the front. It was a deisel and in Amtrak colors (I didn’t get the number, I was driving past it and approached from the rear). It was leading about a dozen hopper cars, orangish-red in color, lettered for Amtrak. On the end was a caboose-looking thing, but it didn’t look like any caboose I’ve ever seen. It was very boxy, and seemed to have oversized walkways on each end. It was the same orangish red as the hopper cars and lettered for Amtrak.

This was parked on a siding near Harrisburg International Airport, on the Harrisburg to Philly line, so it probably has something to do with them rebuilding that line, although no work as been going on in this area. Can anyone tell me more about this train or dig up some pics of it?

Thanks!

It looked something like this, but the locomotive was silver. Seems to be a ballast train.

http://www.railpictures.net/viewphoto.php?id=121007

Probably a work train.

573 is an MP15B purchased from Motive Power and delivered early this year.

Are any of Amtrak’s CF7 locomotives still around in MOW service?

Beechgrove, In (Amtraks repair shop)
My father built some beautiful locomotives from the ground up.
Ill try to locate some pictures.

Work train for service on the NEC

Does Amtrak still have the ex-GO Transit GP40TCs? I saw one at the Albany shops in 2001. Maybe he saw one of those in MoW service?