Union Pacific is partnering with the Bay Area Air Quality Management District and Sacramento Metropolitan Air Quality Management District to re-power 10 low horsepower diesel-electric locomotives into new EPA Tier 4 switchers for its yard switching locomotive fleet beginning in fall 2018. The new switchers will reduce particulate matter and oxides of nitrogen emissions by more than 90 percent during operations when compared to older locomotives.

Tier 4 technology is the EPA's cleanest locomotive emissions standard. Utilizing its multi-engine Genset locomotive, Union Pacific is the only Class 1 railroad operating Tier 4 switchers and is the first Class 1 to pursue Tier 4 re-powers.
"Reducing diesel emissions is an essential element of the Air District's continuing efforts to protect public health in communities that are highly impacted by the Bay Area's freight movement infrastructure," said Jack Broadbent, Air District executive officer. "The Air District is pleased to assist Union Pacific in switching their locomotives to meet the cleanest national air emission standards."
The new single-engine locomotives are designed to ultimately replace the Genset concept Union Pacific pioneered in 2005.
"The new low-power switchers will be an invaluable addition to our fleet," said Mike Iden, Union Pacific director of locomotive engineering. "The coordination with Progress Rail and our partnerships with the Air Districts are pivotal in ensuring this new technology comes online to provide environmental benefits to our California operations."
Funding for the initiative was made possible through the Proposition 1B: Goods Movement Emission Reduction Program (GMERP), a partnership between the California Air Resources Board and local Air Districts, aimed at incentivizing freight-moving equipment owners to upgrade to cleaner technologies.
The switcher units are currently being re-powered at a Progress Rail facility in Patterson, Georgia, and will start joining Union Pacific's yard locomotive fleet in the Bay Area and Sacramento later this year. 
Union Pacific has worked closely with Progress Rail since 2015 on an updated, emission-reducing Tier 4 switcher design. The companies are working together during the switcher's demonstration operations and in-service verification testing taking place in Union Pacific's City of Industry, California, rail yard.
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