Rail Transport Abbreviations and Acronyms

1. OPU
   Operational Planning Unit
2. OPUG
   Other Passenger Upgrades
3. ORC
   Order of Railroad Cocductors
4. ORC
   Order of Railroad Conductors
5. ORHC
   Orrville Railway Historical Society
6. ORN
   Overlay Radio Network
7. ORR
   Office of The Rail Regulator
8. ORR
   Osage Railroad
9. ORR
   Office of the Railway Regulator
10. OS
    Ordnance Survey
11. OS
    Ontario Southland Railway Inc.
12. OSG
    Operation Safety Group
13. OSGB
    Ordnance Survey
14. OSGR
    Ordnance Survey Grid Reference
15. OSI
    Open Systems Interconnection (iso Standard)
16. OSR
    Ontario Southland Rwy
17. OSRR
    Ohio Southern Railroad Incorporated
18. OTDR
    Optical Time Domain Reflectometer
19. OTM
    On–Track Machine
20. OTMR
    On Train Monitoring Recorder

Last updated: May 24, 2020 — Total entries: 4,035