European Union Agency for Railways

ERA Railway Terminology Collection

The ERA Railway Terminology Collection gathers terms and abbreviations that are contained in the EU legal framework for railway, technical documents produced by bodies which are engaged in the development of important evolution in the railway system and other relevant glossaries.

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Latest release: 1 April 2025

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Starting with "O" (176)

ERA Railway Terminology Collection is a consultation tool, developed to support the sharing of information through the actors involved in running the Single European Railway Area (SERA). The responsibility for the correctness, completeness, accuracy, or reliability of the information in ERA RTC lays upon the authors of the definitions, as they derive from reference documents having their own preparation and approval flow. Users cannot call ERA liable for the use they make of the content. Please consider that when the collection is exported (.csv) and then printed or converted, it becomes uncontrolled.
Term Context Document Type Origin document

Over-moulded cylinder

International Relations

Convention

Convention concerning International Carriage by Rail (COTIF) Appendix C – Regulations concerning the International Carriage of Dangerous Goods by Rail (RID)

Over-Reading amount

ERTMS

Technical Document

ERTMS/ETCS - Glossary of Terms and Abbreviations - version : 4.0.0 - date 05/07/2023

Overhaul

International Standard

ISO

ISO 22163:2023(en) Railway applications — Railway quality management system — ISO 9001:2015 and specific requirements for application in the railway sector

Overhead contact line (OCL)

Energy

TSI

Commission Regulation (EU) No 1301/2014 of 18 November 2014 on the technical specifications for interoperability relating to the energy subsystem of the rail system in the Union

Overhead power line / overhead line equipment

RNE Glossary

Glossary

RNE Glossary - NS_CID_Glossary_2023

Overlap

ERTMS

Technical Document

ERTMS/ETCS - Glossary of Terms and Abbreviations - version : 4.0.0 - date 05/07/2023

Overlapping section

RNE Glossary

Glossary

RNE Glossary - NS_CID_Glossary_2023

Overpack

International Relations

Convention

Convention concerning International Carriage by Rail (COTIF) Appendix C – Regulations concerning the International Carriage of Dangerous Goods by Rail (RID)

OVERPANAMAX/ POST PANAMAX

Freight

Glossary

Terminology on Combined Transport from Economic Commission for Europe (UN/ECE). Prepared by the UN/ECE, the European Conference of Ministers of Transport (ECMT) and the European Commission (EC). UNITED NATIONS - New York and Geneva, 2001

Overpressure generation

Freight

Glossary

Handbook of scenarios for assessing major chemical accident risks JRC106029 - Ed. 2017

Override EOA speed

Operation

TSI

Commission Implementing Regulation (EU) 2019/773 of 16 May 2019 on the technical specification for interoperability relating to the operation and traffic management subsystem of the rail system within the European Union and repealing Decision 2012/757/EU

Override EOA speed

ERTMS

ERA Technical Document

Technical Document ERTMS Operational Principles and Rules ERA_ERTMS_OPE_AppA_5 / V 5.0 on 09.04.2019

OVIDE

EU Policy

EU Technical Document

Technical document from the Publications Office of the European Union - ‘Style guide’ Coordination Interinstitutional Style Guide - version on 19.04.2022

Own resources

EU Policy

Glossary

EU budget glossary - A list of the most common words and useful terms concerning the EU budget

OWW

Freight

Glossary

Transport of dangerous goods. Risks Management Framework. Framework glossary v. 1.0/2018

Oxygen consumption principle

International Standard

ISO

ISO 5660-1:2015(en) Reaction-to-fire tests — Heat release, smoke production and mass loss rate — Part 1: Heat release rate (cone calorimeter method) and smoke production rate