Now that Cummins has announced that their new engine is Tier 4 compliant, I am wondering how clean burning are the BNSF LNG engines, compaired to a standard EMD 645, 710, GE 7FDL and the GEVO's?
Two BN SD40-2 engines(7149 & 7890) were converted in 1991 and ran in a test program through 1996. There were converted back to straight diesel power after the program concluded. The 'fuel tender' was last sitting in Staples, MN about a year or two ago. The engines started on straight diesel fuel and the LNG was then fed in once they were warmed up. I am not sure if there was any fuel emissions testing done on them, as fuel cost was the only factor back then.
The new Cummins 'high speed' diesel is Tier 3 compliant and they are working on Tier 4 as most locomotive builders are at this point. I suspect the power plant will use some type of Urea scrubber to achieve Tier 4.. The Cummins news release states that they plan to meet Tier 4 in 2014.
Jim
Modeling BNSF and Milwaukee Road in SW Wisconsin
IIRC, the dual fuel 645 conversions have an issue with NOx emissions which would make them non- tier compliant.
According to the releases Cummins is putting out the new QSK95 and QSK120 will be available in LNG fueled versions. The engines do use a Urea based SCR system, just like Cummins newest OTR engines.
Both GE and EMD's new corporate parent Caterpillar offer "Off-the-shelf" LNG fueled engines. Cat's engine line includes both dual- fuel and spark- initiated gas engines and GE has the Jenbacher line of spark- initiated engines. So if there is a market for LNG fueled locomotives, they don't have to rely on trying to convert existing medium speed diesels..
If you are just wondering about Tier VI complance, keep in mind that EMD has apparently developed a 100% Tier compliant 710 Engine that burns diesel fuel and doesn't require the Urea injection system that Cummins is using..
"I Often Dream of Trains"-From the Album of the Same Name by Robyn Hitchcock
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