Claus Schlund asked:
"Can anyone ID the boxcar on the left?"
http://www.loc.gov/pictures/item/owi2001015034/PP/resource/

PRR Class X23.  The horizontal members of the truss were often (but not always) removed from cars during their service lives.
http://prr.railfan.net/freight/freightphotos.html?photo=PRR_499656_X23_side_RS_Elkhart_IN.JPG&fr=clX23
 
As with the related Class X25 steel boxcar, these cars were massively overbuilt - Gary Rausch showed a photo of a Class X23 boxcar with a collapsed coaling tower on top of it.  The car was in surprisingly good shape.
 
 
Ben Hom