| 1 | HRRX | On-Track Railcar Services, Inc. | added 4/1988; eliminated 10/1988; added 4/1989; 1/1994-7/2005; eliminated 10/2006; eliminated 4/2007 | | NAKINA |
| 2 | HRRX | Consolidated Transportation Corp. | added 4/1984 | | NAKINA |
| 3 | HRRX | Bankers Tank Car Management, Inc. | added 1/1976; 1/1980; eliminated 4/1984 | | NAKINA |
| 4 | HRRX | Bankers Tank Car Management, Inc. | 1/80; eliminated 4/84 | | NRHS |
| 5 | HRRX | Consolidated Transportation Corp. | added 4/84 | | NRHS |
| 6 | HRRX | On-Track Railcar Services, Inc. | added 4/88; eliminated 10/88; added 4/89; 1/94-7/2000 | | NRHS |
| 7 | HRRX | *CONSOLIDATED TRANSPORTATION CORP. {BANKERS TANK CAR MANAGEMENT, INC.] | | | PWRC |
| 8 | HRRX | *ON-TRACK RAILCAR SERVICES, INC. | | | PWRC |
| 9 | HRRX | Conrail (On-Track Railcar Services) | | | RSRV |
| 10 | HRRX | THE HILL RAILROAD CAR COMPANY | | | SCAC4 |
