|Progression in NOx and PM standards for switch locomotives (one of the regulated categories). Click to enlarge.|
The US Environmental Protection Agency (EPA) has finalized its Tier 3 and Tier 4 emissions standards for locomotives and marine diesel engines. Tier 3 emission standards will take effect in 2012, followed by Tier 4 in 2015.
The final requirements will bring earlier and greater emission reductions of NOx and PM from the locomotive and marine sectors than the proposed program envisioned. This is accomplished by finalizing the first-ever national standards for remanufactured large commercial marine diesel engines (above 600kW) and starting Tier 4 NOx requirements for line-haul locomotives and for the largest (2,000-3,700 kW) marine engines two years earlier than initially proposed.
EPA estimates 90% PM reductions and 80% NOx reductions from engines meeting the ultimate Tier 4 standards, compared to engines meeting the current Tier 2 standards. By 2030 this program will reduce annual emissions of NOx by about 800,000 tons and PM emissions by 27,000 tons and those emission reductions continue to grow beyond 2030 as fleet turnover is completed.
Nationwide, this regulation will help prevent 1,400 premature deaths, and 120,000 lost workdays annually in 2030, according to the EPA. The estimated annual health benefits are valued between $8.4 billion and $12 billion. When these older locomotive and marine engines reach the end of their useful life, and new engines enter into the nation’s diesel fleet, the benefits of the new rules will increase.
The rule cuts emissions from all types of diesel locomotives, including line-haul, switch, and passenger rail. The regulations apply to both newly manufactured marine diesel engines and remanufactured commercial marine diesel engines above 600 kw (805 hp) with displacement of less than 30 liters per cylinder installed on vessels flagged or registered in the United States.
These are commonly referred to as marine diesel engines and are divided into three categories for the purposes of EPA’s standards. The cut points for the standards have been revised in the final rule to ensure that the appropriate standards apply to every group of engines.
Category 1 represents engines up to 7 liters per cylinder displacement. Category 2 includes engines from 7 to 30 liters per cylinder. Category 3 engines are those at or above 30 liters per cylinder. Category 3 engines are not included in this rule. They are typically used for propulsion on ocean-going vessels and will be addressed in a separate EPA rulemaking.
Marine diesel engines covered by this proposal are used in a variety of applications. Commercial propulsion applications range from fishing and tug boats to Great Lakes freighters. Recreational propulsion applications range from sailboats to super-yachts. Auxiliary power units range from small generator sets to large auxiliary engines on ocean-going vessels.
For the first time, this rule requires remanufacturing standards for marine engines, reductions in engine idling, and the use of aftertreatment technology that will further reduce diesel emissions. Phasing in tighter long-term standards for PM and NOx will begin in 2014 for marine diesel engines and in 2015 for locomotive engines. Advanced after-treatment technology will apply to both types of engines.
Locomotive and marine diesel engines contribute significantly to air pollution in many cities and towns. EPA anticipates that over the next few decades, these engines may account for an even greater share of overall emissions as other emission control programs take effect for cars and trucks and other nonroad emissions sources. Estimates show that, without the emission reductions from this final action, by 2030 locomotive and marine diesel engines would contribute more than 65% of national mobile source diesel PM2.5, or fine particulate, emissions and 35% of national mobile source NOx emissions, a key precursor to ozone and secondary PM formation.
About 144 million people in the US live in areas that violate air quality standards for ground-level ozone, as of October 2007, and about 88 million people live in areas that violate air quality standards from PM. The locomotive and marine diesel emissions reductions will particularly benefit those who live, work, or recreate in and along our nation’s coastal areas, rivers, ports, and rail lines.
|Switch Locomotive Emission Standards (g/bhp-hr)|
|Year of original mfr||Tier of standards||NOx||PM||HC||CO|
|2015 or later||Tier 4||1.3||0.03||0.14||2.4|