I don't know how we've gone from CAT powered ( C175 and 3500 series diesels) to bunker C fuel. The problem with bunker C is that the reason its so cheap is that it has 2% sulfer instead of 0.2% sulfer of no.2 type fuel. On ships they can build large exhaust scrubbers into the deckhouse over the engine, much like in a coal fired electric plant.
About 40 years ago New York Ferries was required to use low sulfer bunker C fuel that cost almost as much as No. 2 diesel so they went to diesel ferries and that' how EMD got its foot in the door.
I am no expert on maritime diesels. But, I do watch the Discover Channel. In documenting the outshopping of a modern cruise ship this issue was addressed. Out in international waters, the ship switches to bunker C. Coming into national waters, the diesels switch to a lighter environmentally friendlier flue. It was mention cargo and container ships do the same. In reading other news items again the issue came up where by some future date (2030?) bunker C would be phased out. The shipping lines are not happy with that maindate as the operational costs would go way up. Hence passing on the additional cost to the shipper and you and me in the end. Of course, we can always go back to the future, put the Cutty Sark back on-line.
YoHo1975Correct me if I'm wrong, but the new EMD24 engines that UP bought to replace the Gensets in California are using Cat 4 cycle engines with DEF are they not?
To be a little more specific, the EMD24 is supposed to be powered by the 3512C-HD, with the Progress "CEM" package providing the Tier 4 final capability. As of January 2019 this still contains the idiot particulate filter and the somewhat-useless 'catalytic converter' (called a diesel oxidation catalyst or DOC).
The test EMD24 worked on Pacific Harbor Line for 3000 hours, with emission testing by Southwest Research Institute (San Antonio, not to be confused with Stanford's SRI). Perhaps this time will be the charm.
My understanding is that it's fantastically easy to achieve Tier 4 final emissions out of a 710 using DEF. It was the railroad-requested ability to do so without the added consumable requirements and hassles that has caused EMD most of the problems with that engine.
Situation in the F125s is very different, and is much more related to engineering issues in the CEM than to anything in the powerplant per se. From what data have gotten out about it, that is.
BaltACDAre the large marine diesels subject to the same Tier enviornmental restrictions that railroad locomotives are?
No. They are in a different category (see 40 CFR 1042-3 with specific reference to the table attached to 1042.104) and their regulations were written to harmonize with Reg 13 MARPOL Annex VI from about a decade ago.
NOx limits (up to 130rpm) 3.4g/kWh (remember a nominal hp is 746W). There is a strict limit on sulfur, but it can either be met by low-sulfur fuel or by aftertreatment to 6g/kWh or less.
In answer to your next likely question, yes, the law allows testing on 'distillate' fuel rather than typical heavy oil. And yes, they're aware of the likely differences.
I'll bet Leo Ames knows plenty on this subject.
Correct me if I'm wrong, but the new EMD24 engines that UP bought to replace the Gensets in California are using Cat 4 cycle engines with DEF are they not?
My impression of the Cat motored units is that in the end, EMD 4 axle medium horsepower engines were more reliable and better understood, so it was hard to get enough market traction to work the bugs out. Then Gensets took over, but now with Gensets proving less than adequate, maybe there is a market again. Especially now that they have EMD engineering to help?
It was asked in another thread, but looks like in this thread that DEF is not so easy in the railroad application of the 710?
One has to imagine that a DEF retrofit of the 710 or 645, if it could fit on a 4 axle would be extremely popular.
[quote user="BaltACD"]The marine diesels I am talking about would sink the boats you are talking about
Those engines run on bunker C fuel and they claim they can clean it up and those engines that Bay Shipbuilding were running on bunker C also. As I understand it they are bulky units but there is plenty of space above a ships engine and they also have a riding mechnic that loco motivedon.t have.
creepycrankThe point is that locomotives don't like anything in the exhaust like mufflers so adding a catalyst to an older unit might not be a good idea at least for locomotives.
Would you not treat the catalyst chamber as a 'resonator' of sorts and reduce the subsequent 'silencing' restriction to preserve the emitted EPA volume and noise characteristics? There certainly seems to be little concern with actual back pressure throwing off metering of DEF (except perhaps for the seemingly-hapless Progress engineers involved with the Metrolink F125s) but explicit muffling (in at least one Australian case reported by Peter Clark, very substantial muffling) seems to be an accepted part of modern Tier 4 solutions even without SCR added.
Keep in mind that the SCR catalyst is a very different thing from those idiotic particulate trap things (with similar acronym to DEF meaning something like "diesel exhaust filter") that are little better than feel-good amelioration (they trap just about 0% of the actually health-dangerous emitted PM, which is at nanoscale) but provide genuinely asinine levels of performance restriction and of course impose a fuel penalty for default 'regeneration'. No one but a moron or a Californian would call for one of those things instead of regulating combustion to minimize PM emissions in the first place.
creepycrankLocomotive sized engines are rated the same in marine service. the difference is in the load profile. Ocean going and towboats typically run at a 95% load factor and harbor tugs maybe at only 20 % or some full power pushes with a lot of low load high speed running. If you look at turbos sent in for rebuilding, those from peaking generators only have a light dusting of light grey powder. The marine units will have black soot and the locomotive units will partially plugged with a black gooey mass. The point is that locomotives don't like anything in the exhaust like mufflers so adding a catalyst to an older unit might not be a good idea at least for locomotives. Marine engines have mufflers already there probably won't be a problem and they can also periodically do an "Italian tuneup". Bay-shipbuilding already has a lot of experience in applying SCR catalysts to existing ships so we'll have see what happens.
If you look at turbos sent in for rebuilding, those from peaking generators only have a light dusting of light grey powder. The marine units will have black soot and the locomotive units will partially plugged with a black gooey mass. The point is that locomotives don't like anything in the exhaust like mufflers so adding a catalyst to an older unit might not be a good idea at least for locomotives. Marine engines have mufflers already there probably won't be a problem and they can also periodically do an "Italian tuneup".
Bay-shipbuilding already has a lot of experience in applying SCR catalysts to existing ships so we'll have see what happens.
The marine diesels I am talking about would sink the boats you are talking about - I am talking about the ones used on ocean going Pannamax container ships and other bulk carriers where the bore and stroke get measued in feet instead of inches.
Never too old to have a happy childhood!
Locomotive sized engines are rated the same in marine service. the difference is in the load profile. Ocean going and towboats typically run at a 95% load factor and harbor tugs maybe at only 20 % or some full power pushes with a lot of low load high speed running.
Are the large marine diesels subject to the same Tier enviornmental restrictions that railroad locomotives are?
SD70DudeProbably the best example is Norfolk Southern testing a variety of CAT-engined Progress Rail models (all the way up to these monsters) https://www.railpictures.net/viewphoto.php?id=413142 for years, and then ordering hundreds of SD70ACe's with time-tested EMD 710 engines. Actions speak louder than words.
https://www.railpictures.net/viewphoto.php?id=413142
for years, and then ordering hundreds of SD70ACe's with time-tested EMD 710 engines. Actions speak louder than words.
We should probably note that CP has GP-20CECOs and SD30C-ECOs and seems to like them just fine -- they have time-tested 710 "technology".
A big piece of the relative lack of interest in the CAT-derived engines is the failure of the United States EPA to actually mandate use of SCR for large diesel engines. (In my opinion, were they actually interested in improving putative emission of NO from railroad locomotives, this is precisely what they should have done, because it permits Tier 0 or lower engines to achieve arbitrarily low NO emissions almost regardless of how efficiently they are set up and tuned, now with 'plausible denial' to pass the cost of the SCR infrastructure along to 'customers' just as fuel surcharges have been used.
Instead, they likely played games by setting the spec arbitrarily just out of effective range of EMD's solutions for two-strokes without use of DEF, putting EMD and Progress between a rock and a hard place when it came to satisfying 'the lawyers' and the railroad's buyers at the same time.
I would stress, however, the somewhat-anticipatable reaction of the railroads to Tier 4 final by (1) overwhelmingly going to massive rebuilding of older power wherever practical, and (2) apparently mothballing Tier 4 compliant locomotives early almost every time there's a traffic downturn (this probably involving more than just the fuel savings).
I continue to be mystified, although not particularly surprised, by Caterpillar's management not building locomotives with 'their' engines that railroads like long-term. To my knowledge there was exactly one (Ontario Northland, to continue the Canadian connection) that ran a 351x repower in regular mainline service. There are dual-modes running every day with Cat engines, although admittedly in overpriced devices with political design requirements. As I said on Loconotes, I still don't quite understand why the C175 platform hasn't made inroads 'somewhere' after all the work and time CAT put into it, and how proud they were of debugging and evolving the design.
The 4 CN have leased/testing spending A LOT of time sidelined makes me think CN doesn't care for them.
10000 feet and no dynamics? Today is going to be a good day ...
Not that much, judging by the relative lack of orders.
Probably the best example is Norfolk Southern testing a variety of CAT-engined Progress Rail models (all the way up to these monsters) for years, and then ordering hundreds of SD70ACe's with time-tested EMD 710 engines.
Actions speak louder than words.
Greetings from Alberta
-an Articulate Malcontent
What do the railroads think of the Progress Rail locomotives (e.g.: PR 24B, PR 30C. etc.)
Caldreamer
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