You are here
Federal Exhaust Emissions Standards for Locomotives
(g/bhph except where noted)
KEY: bhp-hr = brake horsepower-hour; CO = carbon monoxide; g = gram; HC = hydrocarbon; NOx = nitrogen oxides; PM = particulate matter; hp = horsepower; U = data are not available.
a Standards apply to locomotives that are propelled by engines with total rated horsepower (hp) of 750 kilowatts (kW) (1006 hp) or more, unless the owner chooses to have the equipment certified to meet the requirements of locomotives. This does not include vehicles propelled by engines with total rated horsepower of less than 750 kW (1006 hp); see the requirements in 40 Code of Federal Regulations (CFR) Parts 86, 89 and 1039. The test procedures specify chassis-based testing of ocomotives. These test procedures include certification testing, production line testing, and in-use testing using the Federal Test Procedure (FTP) when the locomotive has reached between 50-70 percent of its useful life.
b Line-haul locomotives are powered by an engine with a maximum rated power (or a combination of engines having a total rated power) greater than 2300 hp. Switch locomotives are powered by an engine with a maximum rated power (or a combination of engines having a total rated power) of 2300 hp or less.
c The line-haul duty-cycle is weighted toward operation in the higher power notches and is typical of line-haul applications (with a maximum rated power greater than 2,300 hp). The switch duty-cycle is typical of switch operations, with more emphasis on idle and low power notch emissions (with a maximum rated power of 2,300 hp or less). Locomotives generally are required to meet the standards for both duty-cycles.
d Line-haul locomotives subject to the Tier 0 through Tier 2 emission standards must also meet switch standards of the same tier.
e The Tier 0 standards apply for 1993-2001 locomotives not originally manufactured with a separate loop intake air cooling system.
f Tier 3 line-haul locomotives must also meet Tier 2 switch standards.
g Manufacturers using credits may elect to meet a combined nitrogen oxides (NOx) plus hydrocarbon (HC) standard of 1.4 grams per brakehorsepower-hour (g/bhp-hr) instead of the otherwise applicable Tier 4 NOx and HC standards.
h Tier 1 and Tier 2 switch locomotives must also meet line-haul standards of the same tier.
i The numerical emission standards for HC must be met based on the following types of hydrocarbon emissions for locomotives powered by the following fuels: (1) alcohol: total hydrocarbon equivalent (THCE) emissions for Tier 3 and earlier locomotives, and non-methane hydrocarbon equivalent (NMHCE) for Tier 4; (2) natural gas and liquefied petroleum gas: non-methane hydrocarbon (NMHC) emissions; and (3) diesel: total hydrocarbon (THC) emissions for Tier 3 and earlier locomotives, and NMHC for Tier 4.
j Manufacturers may elect to meet a combined NOx+HC standard of 1.4 g/bhp-hr instead of the otherwise applicable Tier 4 NOx and HC standards.
k The line-haul particulate matter (PM) standard for newly remanufactured Tier 2 locomotives is 0.20 g/bhp-hr until January 1, 2013, except as specified in 40 CFR Part 1033.150(a).
l The switch PM standard for new Tier 2 locomotives is 0.24 g/bhp-hr until January 1, 2013, except as specified in 40 CFR Part 1033.150(a).
m The smoke opacity standards apply only for locomotives certified to one or more PM standards or Family Emission Limits (FEL) greater than 0.05 g/bhp-hr. Percentages apply to smoke opacity at steady state/30-second peak/3-second peak, as measured continuously during testing.
n Useful life are expressed in megawatt-hours (mw-hr), years, or miles, whichever comes first. Manufacturers are required to certify to longer useful lives if their locomotives are designed to last longer between overhauls than the minimum useful life value.
o For locomotives originally manufactured before January 1, 2000, and not equipped with mw-hr meters.
U.S. Environmental Protection Agency, Office of Transportation and Air Quality, Locomotives: Exhaust Emission Standards (EPA-420B-16-024, March 2016) available at https://www.epa.gov/emission-standards-reference-guide/epa-emission-stan... as of Nov. 20, 2019.