| 1 | FTTX | TTX Co. | added 1/1992; 1/1994-7/2005 | | NAKINA |
| 2 | FTTX | Trailer Train Co. | added 10/1964; 7/1965-1/1980; eliminated 1/1992 | | NAKINA |
| 3 | FTTX | Trailer Train Co. | added 10/1964 | | NAKINA |
| 4 | FTTX | Trailer Train Co. (FMS flat cars specially equipped to provide for loading of automobile frames) | 7/1965-10/1968 | | NAKINA |
| 5 | FTTX | Trailer Train Co./TTX Co. (flat cars equipped with tie-down devices for loading automobile or truck frames) | 4/1970-1/1994 | | NAKINA |
| 6 | FTTX | TTX Co. (flat cars equipped with tie-down devices for loading automobile or truck frames, equipped with end of car cush.) | 7/2000 | | NAKINA |
| 7 | FTTX | Trailer Train Co. | Jul-65 | | NRHS |
| 8 | FTTX | Trailer Train Co. (FMS flat cars specially equipped to provide for loading of automobile frames) | 10/66-10/68 | | NRHS |
| 9 | FTTX | Trailer Train Co. | Apr-70 | | NRHS |
| 10 | FTTX | Trailer Train Co. (flat cars equipped with tie-down devices for loading automobile or truck frames) | 1/75-1/80; eliminated 1/92 | | NRHS |
| 11 | FTTX | TTX Co. (flat cars equipped with tie-down devices for loading automobile or truck frames) | added 1/92; 1/94 | | NRHS |
| 12 | FTTX | TTX Co. (flat cars equipped with tie-down devices for loading automobile or truck frames, equipped with end of car cush.) | Jul-00 | | NRHS |
| 13 | FTTX | TTX COMPANY | | | PWRC |
| 14 | FTTX | Trailer Train (TTX Corporation) | | | RSRV |
| 15 | FTTX | TTX COMPANY | | | SCAC4 |
