US EPA adopts Tier 3/4 emission standards for locomotives and marine engines

18 March 2008

The US Environmental Protection Agency (EPA) has finalized new emission standards for locomotive and marine engines. The rule includes three components: (1) tightening of emission standards for existing locomotives when they are remanufactured, (2) near-term Tier 3 standards, and (3) long-term Tier 4 standards. The Tier 4 standards will require an 80% NOx reduction and a 90% PM emission reduction relative to today’s Tier 2 standards.

The adopted regulatory language is generally stronger than the EPA proposal of March 2007. Some of the changes include:

• Adoption of standards for remanufactured marine engines,
• Two-year pull-ahead, to 2014, of the Tier 4 NOx requirements for 2000-3700 kW marine engines,
• Tier 4 NOx requirements for model year 2015-2016 locomotives at initial build rather than at the time of remanufacture,
• Inclusion of Class II railroads in the remanufactured locomotives program.

The final rule relaxed emission requirements for recreational vessels which do not need to comply with Tier 4 standards, due to the lack of ultra-low sulfur diesel in the Caribbean and Latin America.

The finalized standards cover all locomotives and some marine diesel engines, as follows:

• Locomotives: With some exceptions, the regulations apply to all diesel line-haul, passenger, and switch locomotives that operate extensively within the United States including newly manufactured locomotives and remanufactured locomotives that were originally manufactured after 1972.
• Marine Diesel Engines: The regulations apply to both newly manufactured marine diesel engines and remanufactured commercial marine diesel engines above 600 kW or 800 hp with displacement less than 30 liters per cylinder installed on vessels flagged or registered in the United States. These include Category 1 engines up to 7 liters per cylinder displacement (this cut point, formerly at 5 liters, has been revised in the final rule), and Category 2 engines from 7 to 30 liters per cylinder. Marine diesel engines covered by the rule are used in a variety of applications. Commercial applications range from fishing and tug boats to Great Lakes freighters. Recreational applications range from sailboats to super-yachts. Auxiliary power units range from small generator sets to large auxiliary engines on ocean-going vessels.

  Category 3 engines, at or above 30 liters per cylinder, are not included in the rule. They are typically used for propulsion on ocean-going vessels and will be addressed in a separate EPA rulemaking.

The standards for remanufactured existing locomotives and marine diesel engines take effect as soon as certified remanufacture systems are available, as early as 2008.

The Tier 3 standards for newly-built locomotive and diesel marine engines phase-in starting in 2009. The rule also creates new idle reduction requirements for new and remanufactured locomotives and establishes a new generation of clean switch locomotives, based on clean nonroad diesel engine standards. Tier 3 standards reflect the application of engine based technologies to reduce engine-out PM and NOx emissions.

The Tier 4 standards for newly-built engines phase-in beginning in 2014 for commercial marine diesel engines and 2015 for locomotives (Tier 4 standards do not apply to recreational marine engines). These standards are based on catalytic aftertreatment technology such as diesel particulate filters and selective catalytic reduction (SCR). Tier 4 standards are enabled by the availability of ultra-low sulfur diesel fuel with sulfur content capped at 15 parts per million, which will be available by 2012.

The adoption of the standards was praised by environmental groups. GE, the largest US locomotive manufacturer, said the technology to comply with the Tier 4 requirements does not exist, but the company supports the regulation. GE strongly criticised the EPA proposal after it was published last year.

Source: US EPA