These PDF data files summarize prototypes that are similar to Accurail freight car models.
1150 Series – 36-foot Fowler, single sheathed box cars (6 MB file)
1300 series – 36-foot, double sheathed box cars with steel roof, steel ends, and fishbelly underframe (3.3 MB file)
1400 series – 36-foot, double sheathed box cars with steel roof, steel ends, and straight underframe (2.7 MB file)
1700 series – 36-foot, double sheathed box cars with steel roof, wood ends, and fishbelly underframe (3.6 MB file)
1800 series – 36-foot, double sheathed box cars with steel roof, wood ends, and straight underframe (3.6 MB file)
A tutorial on building the Accurail 36-foot box car kit fishbelly underframes (4 MB file)