CR
| Conrail | 3 |
CSX
| CSX Railroad | 1 |
GREX
| Georgetown Rail Equipment Company | 1 |
IC
| Illinois Central | 1 |
LMIX
| Loram Maintenance of Way Inc. | 1 |
MKT
| Missouri-Kansas-Texas | 1 |
NKP
| Nickel Plate | 1 |
NS
| Norfolk Southern | 25 |
NW
| Norfolk & Western | 13 |
PC
| Penn Central | 1 |
SCL
| Seaboard Coast Line | 1 |
SOU
| Southern | 8 |
SSW
| St Louis Southwestern (Cotton Belt) | 2 |
UP
| Union Pacific Railroad Company | 1 |
WAB
| Wabash | 2 |