International: Locomotives: Emissions

International: Locomotives: Emissions

Overview

Emissions standards for international railways are set by the International Union of Railways, an association of railway firms, via technical leaflets that outline emissions parameters for CO, HC, NOX, and PM emissions. The current standards are outlined in UIC Leaflet 264.

Standard type
Conventional pollutant emission limits
Current Standard
UIC 624-4
Applicability
New engines used in new locomotives or as replacement in existing locomotives of member railways

History

International emissions standards for railway locomotives have been established by the International Union of Railways (Union Internationale des Chemins de fer, UIC), a Paris-based association of railway companies. Founded in 1922, the UIC was created to harmonize the construction and operation standards of railways across Europe and eventually worldwide. The UIC aims to create cooperation within the railway industry on the global level, represent and promote the interests of the industry, and advocate for the development of rail transport. UIC members include companies or organizations, public or private, that are part of a railway transport chain or otherwise involved in railway operations.

UIC issues technical leaflets on railway equipment and components, which are termed “standards.” When standards are updated, a new edition of the leaflet is issued. Standards relate to any aspect of the construction and operation of railways and aim to increase uniformity across borders for the sake of efficiency. Members for whom a standard is applicable approve the standard with a 4/5 vote. More detailed information about UIC’s internal regulatory system and membership eligibility can be found in the UIC Statutes and Internal Regulations leaflets.

The UIC emissions standards for rail locomotives are specified in UIC Leaflet 624, titled “Exhaust emission tests for diesel traction engines.” UIC 624 standards are obligatory for all applicable members. Emissions standards apply to diesel engines for railway traction, with the exception of engines for special locomotives (e.g., refinery or mine locomotives) and traction engines with an output of less than 100 kW. The standards apply to all new engines used in new locomotives or for the repowering of existing ones.

Technical Standards

The emissions standards issued by the UIC are listed below.

UIC 624-1

UIC released the first emissions standards in April 2002 which were in effect until January 2003 when UIC 624-2 replaced them.

Stage Date Power, P Speed, n CO HC NOx PM Smoke
kW rpm g/kWh BSN
UIC 624-1 up to 2002.12.31 3 0.8 12 1.6-2.5a
a – Bosch smoke number (BSN) = 1.6 for engines with an air throughput of above 1 kg/s; BSN = 2.5 for engines below 0.2 kg/s; linear BSN interpolation applies between these two values.
b – For engines above 2200 kW, a PM emission of 0.5 g/kWh is accepted on an exceptional basis until 2004.12.31.

UIC 624-2

The UIC issued the 2nd edition of UIC 624 in January 2003. These were the standard until the 3rd edition replaced them in 2006.

Stage Date Power, P Speed, n CO HC NOx PM
kW rpm g/kWh
UIC 624-2 2003.1.1 P ≤ 560 2.5 0.6 6.0 0.25
P > 560 n > 1000 3 0.8 9.5 0.25b
n ≤ 1000 3 0.8 9.9 0.25b
a – Bosch smoke number (BSN) = 1.6 for engines with an air throughput of above 1 kg/s; BSN = 2.5 for engines below 0.2 kg/s; linear BSN interpolation applies between these two values.
b – For engines above 2200 kW, a PM emission of 0.5 g/kWh is accepted on an exceptional basis until 2004.12.31.

UIC 624-3

In 2006, UIC published the 3rd edition of UIC 624, which became the standard for emissions until 2012 when it was replaced by UIC 624-4. The UIC 624-3 standards are harmonized with the EU Stage IIIA standards for nonroad engines.

UIC 624-4

The UIC issued the 4th edition of emissions standards in 2012. UIC 624-4 is the current standard.

Testing

The test method for UIC emission standards is ISO 8178, cycle F.

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