| 1 | SECX | Southern Extract Co. | 8/1920-4/1938 | | NAKINA |
| 2 | SECX | South-East Coal Co. | added 1/1975; 1/1975-1/1980; eliminated 7/1993; 1/1994 (not listed) | | NAKINA |
| 3 | SECX | General Electric Railcar Services Corp. | eliminated 1/2000 | | NAKINA |
| 4 | SECX | General Electric Rail Services Corp. | added 1/2000; 7/2000 (not listed); eliminated 10/2001 | | NAKINA |
| 5 | SECX | Southern Extract Co. (The Mead Corp.) | Apr-38 | | NRHS |
| 6 | SECX | South-East Coal Co. | added 1/75; 1/75-1/80; eliminated 7/93; 1/94 | | NRHS |
| 7 | SECX | General Electric Railcar Services Corp. | eliminated 1/2000 | | NRHS |
| 8 | SECX | General Electric Rail Services Corp. | added 1/2000; 7/2000 | | NRHS |
| 9 | SECX | *SOUTHERN EXTRACT CO. | | | PWRC |
| 10 | SECX | *(NATX) GENERAL ELECTRIC RAILCAR SERVICES CORP. [SOUTH EAST COAL CO.] | | | PWRC |
| 11 | SECX | South-East Coal | | | RSRV |
| 12 | SECX | South-East Coal Co. | | USA | TRAFFIC |