3 March 2007

The US Environmental Protection Agency (EPA) has published its long expected proposed rule detailing new emission standards for diesel locomotives and for marine engines. Following the Advance Notice of Proposed Rulemaking (ANPRM) of 2004, the proposed rule calls for significant reductions in PM and NOx emissions from these engines through a three-part program:

  1. Tightening emission standards for existing locomotives when they are remanufactured,
  2. Setting near-term engine-out emission standards, referred to as Tier 3 standards, for newly-built locomotives and marine diesel engines, and
  3. Setting longer-term standards, referred to as Tier 4 standards, for newly-built locomotives and marine diesel engines.

The Tier 4 standards would be similar in stringency to the Tier 4 standards for mobile nonroad engines adopted in 2004. Meeting the Tier 4 standards is expected to require the use of advanced aftertreatment technologies such as diesel particulate filters and NOx reduction catalysts on locomotive and marine engines.

EPA is also proposing provisions to eliminate emissions from unnecessary locomotive idling and is asking for comment on a concept to reduce emissions from existing marine diesel engines when they are remanufactured.

Applicability. The proposed requirements would cover all locomotives and selected categories of marine diesel engines, as follows:

  • Locomotives: With limited exceptions, the regulations would apply to all 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. The primary exception is that the new remanufacturing standards would not apply to the existing fleets of locomotives owned by very small railroads.
  • Marine Diesel Engines: The regulations would apply to newly-built marine diesel engines with displacements less than 30 liters per cylinder (Category 1 and 2) installed on vessels flagged or registered in the United States.

Marine engines are divided into three categories for the purposes of EPA’s standards. Category 1 are engines above 50 hp and up to 5 liters per cylinder displacement. Category 2 are engines from 5 to 30 liters per cylinder. Category 3 are engines at or above 30 liters per cylinder. EPA is proposing to change the definition of Category 1 and Category 2 engines to reflect a 7 liter per cylinder cut-off. Marine diesel engines at or above 30 liters per cylinder displacement are not included in the proposal; these engines, which are typically used for propulsion on ocean-going vessels, will be addressed in a separate rulemaking, said the EPA.

Emission Standards. The first part of the proposed requirements are more stringent emission standards for existing locomotives when they are remanufactured. These standards would take effect as soon as certified remanufacture systems are available (as early as 2008), but no later than 2010 (2013 for Tier 2 locomotives).

Second, EPA is proposing near-term Tier 3 emission standards for newly-built locomotive and marine engines. These standards, which reflect the application of technologies to reduce engine-out PM and NOx emissions, would phase in starting in 2009.

Third, EPA is proposing long-term Tier 4 emission standards for newly-built locomotives and marine diesel engines. The marine Tier 4 standards would apply only to commercial marine diesel engines above 800 hp and recreational marine diesel engines above 2,000 hp. The Tier 4 standards, based on the application of high-efficiency catalytic aftertreatment technologies, would phase in beginning in 2014 for marine diesel engines and 2015 for locomotives. These standards are enabled by the availability of ultra low sulfur diesel fuel (15 ppm S), which will be available from 2012.

The proposal would result in PM emission reductions of about 90% and NOx reductions of about 80% from engines meeting these standards, compared to engines meeting current EPA standards. The proposed standards would also yield sizeable reductions in emissions of HC, CO, and other air toxics.

EPA estimated that without the emission reductions from the proposal, by 2030 locomotive and marine diesel engines would contribute more than 65% of national mobile source diesel PM2.5 emissions and 35% of national mobile source NOx emissions.

Program Cost. The EPA estimates the annual cost of complying with the proposed program to be about $600 million in 2030. The average price in 2030 of a locomotive is expected to increase by less than 3% (about $49,000 per unit) as a result of the proposed standards.

In the marine markets, the expected increase in engine and vessel prices in 2030 for commercial engines below 800 hp and recreational engines is less than 1%. The average price of a commercial marine diesel engine above 800 hp is expected to increase by about 8.5% for Category 1 engines and about 19% for Category 2 engines. The average price of a marine vessel using these larger engines is expected to increase about 1% for vessels using Category 1 engines above 800 hp (about $16,000) and 3.6% for vessels using Category 2 engines above 800 hp (about $142,000). The expected impacts on prices in the locomotive and marine transportation service market would be less than 1%.

EPA will be accepting comments for 90 days beginning when the proposal is published in the Federal Register. A public hearing will also be held in Seattle, WA, and Chicago, IL, after publication of the proposed rule in the Federal Register.

Source: US EPA (regulatory documents)