Over the past 20+ years diesel locomotive design has become pretty stagnant, aside from advances in emission controls. Given that a 16-cyclinder EMD 1010 or Wabtech GEVO prime mover could potentially generate 6,000 HP, is there any possibility of trying to push the limits of diesel loco design? I would think that a 6,000+ HP prime mover paired with an AC drive BB-BB wheel arrangement could become the ultimate P$R monster train locomotive. That said, I’m sure the Tier 4 EGR fuel efficiency issue is a restraining factor. Kind of pathetic that rebuilt 25-30 year old Dash 9’s and AC4400CW’s are just as capable designs as the latest diesel locos that Wabtech and EMD have to offer. Obviously right now there’s no compellling reason to buy anything new, unless its some sort of battery electric prototype.
Part of the problem is that the fuel efficiency of locomotives that meet Tier 4 standards is less than older models. There also doesn’t seem to be much demand for locomotives of that size.
SD90MAC-2? 
China bought 300 EMD HXN3 6,000 HP H-engined locomotives almost 20 years ago.
Until more efficient technology is brought to bear on attaining Tier 4 standards with better than Tier 3 fuel economy - there won’t be all the many new built Tier 4’s, but a lot of rebuilt Tier 3’s.
In a manner of speaking Tier 4 locomotives are the 1970’s era automobiles with their ‘smog controls’ - inefficient, gas hogs with virtually no power; as automotive technology progressed we have cleaner, more powerful and fuel efficient engines today.
To the OP–Bigger isn’t always better.
SCR on the Tier 4 Siemens Chargers seems to be working fine with plenty of orders from multiple passenger railroads. Prime selling point is the large improvement in fuel efficiency. If you read thru the narrative part of the USEPA locomotive emission regs the EGR control technology selected by the Class I’s wasn’t regarded as being a feasible solution back in 2008 in part due to the fuel efficiency penalty. The Class I’s forced GE and EMD into pursuing EGR because they didn’t want to setup a distribution infrastructure for urea or be forced to shut a locomotive down because it had run out of urea. EMD’s 710 engine probably would have been able to meet Tier 4 with SCR controls. Forcing the use of EGR was short-sighted thinking in my opinion.
All of the large Wabtech GE rebuild programs only meet Tier 1+ standards, which represents no change from the original locomotives with overhauled
As I remember the story, the Chinese locomotives had the original-design 265H engines… and there hasn’t been much, if any, discussion of their having cavitation or other reported issues. Dave Goding might have considerable knowledge of some of the details.
FGR is a nifty strategy for powerplant combustion, and EGR would have similar promise… if there weren’t so many damn problems with it on road and rail vehicles! (Cue Shadow the Cat’s Owner for the many relevant issues!) On the other hand, diesel engines make better fuel economy and emit lower levels of dangerous nanoparticulates when run with high compression ratio at relatively restrained speed and steady state or slow speed changes… the problem being that NOx emissions increase then, and the EPA has (in my opinion) over-demonized nitrogen oxide emissions in the Tier 4 spec. (Remember that NOx has indeed been a factor in photochemical smog, but that required reaction with airborne HC/VOC… which have been tremendously reduced by the combination of better mileage and mandatory catalytic conversion…)
The point is that once a railroad has bitten the bullet, or some agency has government-provided the necessary paraphernalia, regarding locomotive SCR, it becomes possible to crank the compression ratio back up to high levels… and just use slightly more DEF to remediate as close to 100% of the NOx as you can control ammonia slip. This has not caught on, and perhaps with the push to zero-carbon it won’t soon if at all, but it does represent an attractive reason to adopt what EPA has in the past indicated to be its actual priority. without having to fund it as directly mandated.
I’ve made comments in the past about how Tier 4 could backfire, with my argument that a Tier 3.5 could have resulted in more reductions in emissions than Tier 4 because the railroads would likely to buy a lot more Tier 3.5 locomotives. Tier 4 would only be a benefit if railroads would buy Tier 4 locomotives in quantity.
I also remember very similar discussions back in the early 1970’s where many said that one of the things needed to solve the smog problem was to have people keep their cars for longer. The truth was the exact opposite, where the need was to have people stop driving the older cars.
One of the more interesting diesel engine research projects is using a series of tubes around the injectors that will act like Bunsen burners. The idea is that the tubes prevent ignition from occuring until the fuel has a chance to mix with the air, with the combustion process similar to a spark ignited “mxiture” engine (AKA gasoline engine).
Actually holding at Tier 3 would have produced significant gains. The Class I’s purchased ~7,500 Tier 2 and Tier 3 models between 2005 and the late 2010’s (including the so-called Tier 4 credit units). The loco’s not only reduced emissions via their enhanced engine designs, they also contributed to significant fuel efficiency gains. Every gallon of diesel not burned yields a 100% reduction in emissions.
I have been involved in the creation of locomotive emission inventories. Over longer time periods, such as 2007 to 2014, fuel efficiency gains alone were enough to reduce overall rail sector emissions. Add in the cleaner engines and NOX decreased over 145,000 tons despite national GTM’s hitting an all-time high in 2014: https://docs.google.com/presentation/d/1VH085-5Qo0_VAzI3SsMbPcpe16liFN2p/edit?usp=sharing&ouid=118098283392484026734&rtpof=true&sd=true
The other issue with the regs is that they treat all areas of the country the same. California hasn’t been able to meet any of the ozone air quality standards (1979 1-hour 0.12 ppm, 1998 8-hour 0.08 ppm, 2008 8-hour 75 ppb, or 2015 8-hour 70 ppb). States like Illinois have been able to reduce ozone to meet each of the successive ozone standards, except for the latest 2015 standard of 70 ppb. Even with that, air quality in Illinois is just barely over the current standard. California needs zero or near zero emitting locomotives (along with all of the help that they can get with the other mobile source sectors) so that they can even make a dent in their problem. That is not the case for other parts of the country. Tier 4 is overkill and because of the fuel efficiency problem the Class I’s have decided to rebuild Tier 1+ locos en masse. Defeat has been effectively
Have you got a reference or citation for the work? I’d like to see it, because the approach flies in the face not only of efficient compression-ignition design but also Harry Ricardo’s early research in IDI engines (the Comet chamber and the importance of squish) in producing prompt injection without detonation in high-speed powerplants.
Note that GDI engines seem to be taking over from any design involving pre-cylinder carburetion (specifically including any lean-burn or stratified-charge approaches, or even polynucleate autoignition). Unsurprisingly, GDI engines are starting to demonstrate similar generation of nanoparticulates as high-pressure common-rail diesels when operated at high speed and I wouldn’t be surprised that raising the CR would have some effect on reducing this (where diesel oxidation catalysts don’t, and of course DPFs don’t matter at all).
Actually I don’t know how they are doing. I heard 10 years ago that there was an issue of cooling water leakage at the cylinder to block interface but don’t know if that’s been resolved. One of the reasons for redesigning the 265H engine to become the Tier 4 1010J was to avoid having to give the Chinese any improvements as would have been required if it stayed designated as the 265H.
Dave
“265H” means 265 mm bore? And “1010J” means 1010 cubic inches? Same cylinder size on both?
It’s much the same engine, “rebranded” to eliminate the potential negative publicity attributed to the 265H (and now, thanks to inside knowledge, keeping clear of certain potential support disagreements…) I’ll leave it to the ex-EMD people familiar with the engine development to list the detail-design differences; I only got them second- or third-hand. (I for one would like the see the differences between the H-block and J-block given definitively in one place…)
In my opinion it was a fundamentally good engine then, and remains one now.
The change of most significance is the mounting of the alternator to the rear of the engine on cast extensions and the provision for the isolation mounts on the crankcase. The two-stage turbo mountings at the front instead of the rear, intercooler and aftercooler mounting, and EGR plumbing also caused changes as I recall. I believe the whole front end geartrain and water, oil, and high pressure fuel pumps were all changed to work around the charge air coolers.
Yes
Have 16 or 20 cylinder 1010J’s ever been built for non-rail applications? I would presume that the HP potential for such configurations would be pretty high relative to what the rail industry is currently using.
I’d doubt there’d be many 20-cylinder J-block engines for much the same reason there were few SD80s and many SD45s were retired or re-engined early. The situation might be different in marine engines, which is where I’d look for that.
The big issue is that Caterpillar, which owns and controls Progress Rail, uses its own 20-cylinder C175 for genset use as well as for potential high-speed locomotive prime mover capability. Since North American railroads have repeatedly preferred ~4400hp individual units to 6000hp, I wouldn’t expect a 1010J engine to be, well, more than 12 cylinders in a North American freight locomotive. similar to how GE uses 12- and not 16-cylinder power in most of their GEVO-equipped locomotives.
Less power, less fuel efficient and higher purchase cost. That explains all the locomotive rebuild projects in this PSR world.