| 1 | GTTX | TTX Co. | added 1/1992; 1/1994-7/2005 | | NAKINA |
| 2 | GTTX | Trailer Train Co. | added 1/1964; 7/1965-1/1980; eliminated 1/1992 | | NAKINA |
| 3 | GTTX | Trailer Train Co. (FC flat cars equipped with hitches and bridge plates for the transportation of trailers and manufactured by GATC) | 7/1965-10/1968 | | NAKINA |
| 4 | GTTX | Trailer Train Co. (Flat cars, equipped with hitches and bridge plates for the transportation of trailers. Cars built by GATC) | 4/1970-7/1985 | | NAKINA |
| 5 | GTTX | Trailer Train Co./TTX Co. (89' flat cars that have been modified for autorack services that have not been racked) | 10/1991-1/1994 | | NAKINA |
| 6 | GTTX | TTX Co. (89 ft. flat cars that have been modified for autorack service that have not been racked, equipped with end of car cush.) | 7/2000 | | NAKINA |
| 7 | GTTX | Trailer Train Co. | Jul-65 | | NRHS |
| 8 | GTTX | Trailer Train Co. (FC flat cars equipped with hitches and bridge plates for the transportation of trailers and manufactured by GATC) | 10/66-10/68 | | NRHS |
| 9 | GTTX | Trailer Train Co. | Apr-70 | | NRHS |
| 10 | GTTX | Trailer Train Co. (Flat cars, equipped with hitches and bridge plates for the transportation of trailers. Cars built by GATC) | 1/75-1/80 | | NRHS |
| 11 | GTTX | Trailer Train Co. | eliminated 1/92 | | NRHS |
| 12 | GTTX | TTX Co. | added 1/92 | | NRHS |
| 13 | GTTX | TTX Co. (89' flat cars that have been modified for autorack services that have not been racked) | Jan-94 | | NRHS |
| 14 | GTTX | TTX Co. (89 ft. flat cars that have been modified for autorack service that have not been racked, equipped with end of car cush.) | Jul-00 | | NRHS |
| 15 | GTTX | TTX COMPANY | | | PWRC |
| 16 | GTTX | Trailer Train (TTX Corporation) | | | RSRV |
| 17 | GTTX | TTX COMPANY | | | SCAC4 |
