| Abbreviation | Definition |
|---|---|
| TSRR | Tennessee Southern Railroad Company |
| TSSX | U.S. Department of Energy Albuquerque Operations Office |
| TSSX | US Department of Energy Albuquerque Operations Office |
| TSSZ | TAL International (BNSF Railway) |
| TSU | Tulsa-Sapulpa Union Railway |
| TSU | Tulsa-Sapulpa Union Railway Company |
| TSVX | Tennsv |
| TSVX | Tennsv Incorporated |
| TSWR | Toppenish Simcoe and Western Railroad |
| TSXX | Tri- State Generation and Transmission Association |
| TSXX | Tri-State Generation and Transmission Association |
| TSXZ | TAL International |
| TSXZ | Transamerica Leasing Incorporated |
| TT | Toledo Terminal Railroad |
| TTAX | Trailer Train (TTX Corporation) |
| TTAX | TTX Company |
| TTBX | Trailer Train (TTX Corporation) |
| TTBX | TTX Company |
| TTCU | TNC Chemicals |
| TTCU | TNC Chemicals Company |