| 1 | UNSX | Unitrain Services (agent for Iowa Power and Light Co.) | added 10/1980; eliminated 4/1993 | | NAKINA |
| 2 | UNSX | Midwest Power Systems | added 4/1993; 1/1994; eliminated 4/1996 | | NAKINA |
| 3 | UNSX | MidAmerican Energy Co. | added 4/1996; 7/2000; eliminated 4/2003 | | NAKINA |
| 4 | UNSX | JAIX Leasing Co. | added 4/2003; eliminated 1/2004 | | NAKINA |
| 5 | UNSX | Railcar Custom Leasing, LLC | added 1/2004; eliminated 10/2004 | | NAKINA |
| 6 | UNSX | Rail Logistics, LC | added 10/2004; 7/2005 | | NAKINA |
| 7 | UNSX | Unitrain Services (agent for Iowa Power and Light Co.) | added 10/80; eliminated 4/93 | | NRHS |
| 8 | UNSX | Midwest Power Systems | added 4/93; 1/94; eliminated 4/96 | | NRHS |
| 9 | UNSX | MidAmerican Energy Co. | added 4/96; 7/2000 | | NRHS |
| 10 | UNSX | *UNITRAIN SERVICES (AGENT FOR IOWA POWER & LIGHT) | | | PWRC |
| 11 | UNSX | *MIDAMERICAN ENERGY COMPANY [(IOPRX) MIDWEST POWER SYSTEMS] | | | PWRC |
| 12 | UNSX | +RAIL LOGISTICS, LC [RAILCAR CUSTOM LEASING, LLC; JAIX LEASING CO.] | | | PWRC |
| 13 | UNSX | Unitrain Services | | | RSRV |
| 14 | UNSX | RAIL LOGISTICS LC | | | SCAC4 |