| 1 | WITX | Witco Carbon Co. | 1/1950-7/1954; eliminated 10/1956 | | NAKINA |
| 2 | WITX | Continental Carbon Co. | added 4/1958; 4/1961-1/1980; eliminated 1/1985 | | NAKINA |
| 3 | WITX | Continental Carbon Co., wholly owned subsidiary of Witco Chemical Corp. | added 1/1985; eliminated 4/1986 | | NAKINA |
| 4 | WITX | Continental Carbon Co., wholly owned subsidiary of Witco Corp. | added 4/1986; 1/1994 | | NAKINA |
| 5 | WITX | Continental Carbon Co. | eliminated 1/1999 | | NAKINA |
| 6 | WITX | General Electric Railcar Services Corp. | added 1/1999; eliminated 1/2000 | | NAKINA |
| 7 | WITX | General Electric Rail Services Corp. | added 1/2000; 7/2000-7/2005; eliminated 4/2006 | | NAKINA |
| 8 | WITX | CCC Transport Co. | added 4/2006 | | NAKINA |
| 9 | WITX | Witco Carbon Co. | Jan-52 | | NRHS |
| 10 | WITX | Continental Carbon Co. | 4/61-1/80; eliminated 1/85 | | NRHS |
| 11 | WITX | Continental Carbon Co., wholly owned subsidiary of Witco Chemical Corp. | added 1/85; eliminated 4/86 | | NRHS |
| 12 | WITX | Continental Carbon Co., wholly owned subsidiary of Witco Corp. | added 4/86; 1/94 | | NRHS |
| 13 | WITX | Continental Carbon Co. | eliminated 1/99 | | NRHS |
| 14 | WITX | General Electric Railcar Services Corp. | added 1/99; eliminated 1/2000 | | NRHS |
| 15 | WITX | General Electric Rail Services Corp. | added 1/2000; 7/2000 | | NRHS |
| 16 | WITX | *CONTINENTAL CARBON CO., SUBS. WITCO CORP. | | | PWRC |
| 17 | WITX | +CCC TRANSPORT CO. [GENERAL ELECTRIC RAIL SERVICES CORP.] | | | PWRC |
| 18 | WITX | Continental Carbon | | | RSRV |
| 19 | WITX | CCC TRANSPORT COMPANY | | | SCAC4 |