(I've often wondered where the refurbished/remanufactured engines in the 57's came from originally, since there are very few US locomotives using the V12 645s. The V16 has always been the standard EMD freight locomotive engine, there were 8,000+ V16 645 powered locos built for the US market alone versus a relative handful of V12 powered ones).
A decent number of GP and export locos used V12 645 engines.
I would guess that retired GP locos would have been where they came from, as operators could effectively do one-for-two replacement with modern locos in the 3+MW power range with AC traction became available late in the 1990s.
It's interesting that one of the major US railroads is
rebuilding 25-year old GE Dash-8 locos, upgrading the 7FDL16 diesel engines with electronic fuel injection and split cooling systems to take them from Tier 0 to Tier 2 emissions compliance (and reduce the fuel consumption presumably, so less CO2 as well).
I wonder if this sort of emissions-improvement engine rebuilding/modification is allowed under EU emissions rules ?
While the EPA emissions standards for non-road engines are copied by the EU, what is not harmonised is the regulations which rule the implementation of the standards. For example, I understand that the EU has deferred implementation of Tier 4 for rail vehicles, while it is now in force for the US domestic market.
Allowing engines to be upgraded to Tier 2 as in the NS rebuild program is a good pragmatic move by the EPA, and I wouldn't be surprised if there were grants available to help facilitate it. The Dash 8 series locos all had "Tier 0" engines (i.e. predating the standards, Tier 1 compliance came with the Dash 9 series) so upgrading them to Tier 2 is still better than having them keep running in original form - the C40-8 locos are very reliable and should be good for another 20+ years so the upgrade should save a lot of emissions over their remaining life.
Interestingly, the same NS upgrade program also includes rebuilding the short hood into a full-width nose.
(and reduce the fuel consumption presumably, so less CO2 as well).
Not necessarily, it depends on which emissions you are trying to control.
In the case of non-road diesel engines, the main effect of Tier 2 is to control the release of particulates. This is done using filters which have a negative effect on performance and therefore on fuel economy.
