Anyone have the information on whst the problems are and what directions the fixes are taking?
Which problems?Regards, Volker
Yeah, what problems?
Is this in reference to the F125 failure at the unveiling in Los Angeles? If so, those units had been running for a while and I hadn't gotten word on what failed. In either case, there is already a thread here and one in Transit covering that issue.
The SD70AC-T4s seem to be doing fine turning the revenue miles.
This Thanksgiving Day I was briefly by the Metrolink South Perris end of the 91 / Perris Valley line terminus. Four train sets were laying over for the holiday, NONE of which had an F125 unit! Were all F125’s somehow laying over on other Metrolink lines, or does the original thread poster, Dave Klepper, know something that we all don’t?
----------------------------------------------------------------------------------------------------------------------------------- K.P.’s absolute “theorem” from early, early childhood that he has seen over and over and over again: Those that CAUSE a problem in the first place will act the most violently if questioned or exposed.
I think the incident that Mr. Klepper was referring to was the absolutely embarrassing humiliation the Metrolink CEO received in the F125 failure by the Newhall Metrolink station.
https://signalscv.com/2017/11/metrolinks-tier-4-locomotive-unveiling-stopped-in-its-tracks/
Somehow I have to believe the failure was caused by a totally clogged emissions filter, but I have NO official word on it.
Part of the confusion in this thread, I believe, was caused by TRAINS failure to duplicate the Newswire article on the subject in the “Locomotives” forum. I had to find and get someone else in the office here, a subscriber, to sign in and pull up the Newswire article. Why TRAINS didn’t bait the forum with such an important Newswire is beyond me. I guess the West Coast to Wisconsinites is a communist evil empire …
K. P. HarrierSomehow I have to believe the failure was caused by a totally clogged emissions filter, but I have NO official word on it.
The question is what kind of emissions filter as the F125 doesn't have a diesel particulate filter (DPF): http://trainweb.org/carl/2017CaliforniaPassengerRailSummit/Slides/Tripoli/IMG_6236.JPG
The picture is from a presentation held by Rick Tripoli (Metrolink) on the 2017 California Passenger Rail Summit. Here is the link to the complete presentation: http://trainweb.org/carl/2017CaliforniaPassengerRailSummit/Slides/Tripoli/index.html
And here a link to a description of the conference: http://trainweb.org/carl/2017CaliforniaPassengerRailSummit/
Regards, Volker
Edit: There is another thread covering the same topic in the Transit Forum: http://cs.trains.com/trn/f/742/t/266291.aspx
K. P. HarrierI think the incident that Mr. Klepper was referring to was the absolutely embarrassing humiliation the Metrolink CEO received in the F125 failure by the Newhall Metrolink station.
First law of railroading - if it's going to break, it's going to break at the worst place and/or time.
That's why for big public things like that - you should always have a protect engine and crew nearby.
there are lots of things that can go wrong. And many of them have nothign to do with it being a tier 4.
It's been fun. But it isn't much fun anymore. Signing off for now.
The opinions expressed here represent my own and not those of my employer, any other railroad, company, or person.t fun any
zugmannThere are lots of things that can go wrong. And many of them have nothing to do with it being a tier 4.
Or engined with a C175, either, which is why Mr. Klepper changed the topic line of this thread and why I'll be changing mine over in Transit if necessary to reflect what the actual failure causes turn out to be.
I was amused (although with a hefty dose of schadenfreude) watching the Metrolink CEO, because in another thread we were discussing aspects of 'lightweight trains of the future' and I was thinking about the Baldwin RP210 that clogged rush-hour traffic for hours, with the executive responsible saying 'another ten minutes and I would have been a hero...'
No plan survives contact with the enemy, and Finagle is ever vigilant.
"Each day we had a catered lunch - sandwich, chips, cookie, fruit, and soft drink"
Well now isn't that lovely. The most important thing to any government representative in attendance is the free lunch. What no buffet?
If you have anykind of SCR on the engine you have a type of DPF that can clog. It has to be sprayed on a wide area catalyst think like in the converter honeycomb in your car. They do clog and are a royal pain the butt to clean out when they do. So even though they are claiming they don't have a DPF on them yes they do.
Shadow the Cats ownerIf you have anykind of SCR on the engine you have a type of DPF that can clog.
Could you explain then please why Metrolink for the F125 as well as Siemens for the SC44 state that the locomotives don't have DPF?Regards, Volker
SCR stands for Selective Catalyst Reduction in Diesel technology. You spray DEF in the diesel exhaust stream over a catalyst to convert the exhaust into more enviromentially friendly compounds. That catalyst has to be in a honeycomb structure to react with both the DEF and the Exhaust itself to have it flow thru it and convert into CO2 and other compounds from what it was. On OTR trucks we do it in our DPF filters itself since they are part of our exhaust system hence the term DPF with SCR. We also regenerate our DPFs and hence the catalyst about every 40 hours of running time. Trust me the SC44 has an intergal DPF as part of its exhaust system they have changed the name to confuse the railroads and call it a flow thru catalyst trust me they tried the same freaking thing about 10 years ago to the OTR industry and said oh we got rid of the DPF and replaced it with a flow thru cat system. It is a DPF under a different name and they will admit that they require regens like the OTR engines in a few months when the so called no regen ones keep causing breakdowns like what we saw in CA.
VOLKER LANDWEHR Edit: There is another thread covering the same topic in the Transit Forum: http://cs.trains.com/trn/f/742/t/266291.aspx
It was also already mentioned in the other F125 thread before this thread was started.
Which is probably why they didn't sticky the news wire. We were already talking about it in 2 places...now 3.
Shadow the Cats ownerSCR stands for Selective Catalyst Reduction in Diesel technology. You spray DEF in the diesel exhaust stream over a catalyst to convert the exhaust into more enviromentially friendly compounds.
Agreed, but nevertheless I stay with the statement from Metrolink and Siemens that the F125 and SC44 don't have DPF. And there are reasons.
- usually the DPF is before the SCR in the exhaust stream to keep PM out of the SCR catalyst.- EMD 1010-T4 and GE Gevo-T4 use solely EGR to comply with locomotive Tier 4 emmisions. The cooler combustion temperature reduces NOx but increases PM. But still both locomotive get away without DPF through cleaner combustion (common rail injection).- Cummins writes in a broschure: The QSK95 is ready to meet Tier 4 and other very low emissions standards, using in-cylinder clean combustion to reduce Particulate Matter (PM) emissions and Selective Catalytic Reduction (SCR) aftertreatment to reduce Oxides of Nitrogen (NOx) emissions. EMD and GE were able to reduce PM by clean combustion why should Cummins not be able to do the same.- Last but not least: Truck PM Tier 4 limits are 0.01 g/bhp-hr, locomotive PM Tier 4 limits are 0.03 g/bhp-hr, three times the truck limit.Regards, Volker
Does the technology used in the SC44 differ from that used in the F125?
The SC44's seem to be successful.
Volkner the SCR is a catalytic converter on a diesel engine that is instream of the exhaust. Everyone of my bosses 250 trucks has one of those on it except for the spotters except ours are in our Particulate Filters that are in the exhaust stream also. Cummins and Cat both are trying some selective wording to get around the Railroads not wanting to buy DPF's for their engines. You can not have anykind of Catalytic converter without it having a microscopic honeycomb design in it for the exhaust to pass thru the catalyst. The catalyst itself acts like a filter and yes Felica to borrow a phrase from my daughter they DO CLOG UP. That is when you have to REGEN the freaking thing and at least on our trucks even at our standards we still have to regen both our DPF's and our SCR's. Cat better admit the SCR on their engines need regens or they are going to be in a heap of trouble with the F125 model. Cummins is smart enough that when the SCR is doing its thing it gets almost hot enough to burn out the carbon loading however it still requires a peroidic regen to clean it.
Thanks --- all. So a clogged filter or clogged filters MAY have been the stall problem.
Hope that is so. Setting up a regular cleaning process might be preferable to rebulding the lomotives.
daveklepperSo a clogged filter or clogged filters MAY have been the stall problem.
A lot of things might have caused this failure, from software problems to mechanical problems with everything in between.
I still don't buy that the F125 has a DPF. The EMD and EGR only engines don't require DPF though the produce more PM than an engine without EGR. The solved the problem with cleaner burning measures like common rail injection.
So why should a SCR aftertreatment engine with the same cleaner burning measures but less PM need a DPF? If a SCR can clogg I don't know.
To say a locomotive engine with SCR needs a DPF because a truck needs it doesn't work. The locomotive's PM limits are at least three times higher.Regards, Volker
I'm not sure a clogged filter seems particularly probable. Does anyone know, is the C175's SCR system in the F125 the same as the one previously used in other Tier 4 applications of that engine? I thought the C175 system was at least used in other non-railroad applications.
I will try to explain it as my companies maintance manager once explained it to me. In a diesel engine there is no catalyst out there discovered yet that can convert the exhaust to less polluting gasses without the addition of DEF or urea. So they inject a mist of urea into the exhaust stream just ahead of the catalyst that is in the SCR chamber of the exhaust system. That catalyst is made up of a honeycomb of a material and it will clog we have seen it happen even with our Tier 4 emission standards so don't say it won't happen. Also Cat is brand new to using SCR peroid they refused to even consider it on anything for years and fell behind the learning curve with it.
I know how the SCR works. What I don't see is the need for a DPF. And please don't compare truck and locomotive Tier 4 diesel directly without taking into consideration the different PM limits.
Cat might be new to use of SCR but Cummins isn't and they use SCR without DPF too.Regards, Volker
Shadow the Cats owner I will try to explain it as my companies maintance manager once explained it to me. In a diesel engine there is no catalyst out there discovered yet that can convert the exhaust to less polluting gasses without the addition of DEF or urea.
I will try to explain it as my companies maintance manager once explained it to me. In a diesel engine there is no catalyst out there discovered yet that can convert the exhaust to less polluting gasses without the addition of DEF or urea.
The trick with gasolene (mixture/spark ignited) engines was to use a three-way catalyst, such as the one developed by Universal Oil Products in the early 1970's. There was a very speciific requirement with this approach in the the fuel/air ratio had to be almost exactly stoichemetric. Difficulties with maintaining precise control over the fuel/air ratio put the kibosh on use of that catalyst until a Volvo engineer read a a NASA Tech Briefs report on an oxygen sensor.
Diesel engines are almost always run with a lean fuel/air ratio (excess air), so the catalyst used with gasolene engines won't work with diesels.
This brings back memories of freshman chem lab, where one experiment involved using urea to get rid of the red fumes in the flask, where the red fumes were NO2 and N2O4. At least I wasn't told to use hydrazine to clear out the NOx.
VOLKER LANDWEHRI know how the SCR works. What I don't see is the need for a DPF. And please don't compare truck and locomotive Tier 4 diesel directly without taking into consideration the different PM limits. Cat might be new to use of SCR but Cummins isn't and they use SCR without DPF too. Regards, Volker
Someone in another F125 thread said "The Vossloh Eurolight ... is offered with the same C-175 engine as EU stage IIIb compliant using SCR and DPF instead of the exhaust silencer." Does that imply that European PM standards are that much more stringent? I certainly agree that in most American practice a locomotive needs a DPF like a fish needs a bicycle.
In any case, I think it was something of a misstatement for this discussion to get on the whole "DPF" business in the beginning, as it's not a DPF regenerable with rich fueling that's involved with a prospective model for the Newhall F125 shutdown; it would be clogging of the relatively fine passages in the SCR catalyst modules. For this to be happening I'd expect that long before you got physical plugging effects, you'd see the ammonia slip going out of sight as the active surface area of catalyst -- the reason for all the fine passages in the SCR modules -- would be covered up or gas access blocked. So there, too, I would suspect physical clogging would not be a cause. Overzealous computers modally shutting down the engine for something like ammonia slip ... that might be closer to the issue.
Up to now I had seen no reference to using the same procedure to clear a presumably gunked-up SCR apparatus that is routinely (mis)used to clear a DPF. All the references I have indicate that 'regenerating' the catalyst in SCR is done externally, either chemically or by physically replacing or augmenting the media that are plated with the 'active' material. It is in my opinion a stupid idea to clean PM and other gunk out of a catalyst with high uncontrolled heat, for a variety of reasons and no particular operational 'upside', especially if either the thin layer structure or the chemical 'reactivity'of catalyst material is damaged by overheating (as I expect it would be). But then again, flaming out a DPF at the cost of up to 6% fuel efficiency, particularly when net carbon emissions are reckoned as part of the 'pollution', is inane in the first place, and as noted the whole DPF concept as currently implemented does very little to solve the actual biological danger from 'particulate matter' emissions in diesels or other direct-injected IC engines...
[I admit to being a little overwrought on the general topic of catalysts and heating, having just had a severe cat fire on my BMW 850i, I think thanks to idiots misadjusting the fuel-injection control to be effectively too rich during repeated starts]
OvermodSomeone in another F125 thread said "The Vossloh Eurolight ... is offered with the same C-175 engine as EU stage IIIb compliant using SCR and DPF instead of the exhaust silencer." Does that imply that European PM standards are that much more stringent?
I remember the quote. I re-read the source (Wikipedia): The CAT engines meet European Stage IIIA emission standards, and can be modified to meet 2012 IIIB emission standards by replacing the exhaust silencer with a diesel particulate filter.
Somehow I added the SCR. Sorry for that. I haven't found a Vossloh/Stadler sheet showing the Euro IIIb measures on new built locomotives.
The Euro IIIb PM limit is 0.034 g/bhp-hr.
I do understand that a wall-flow DPF will clogg and needs regeneration. The diesel particulate matter have to go through the walls with about 10 µm pores.
The SCR has between 200 to 400 channels per square inch going through the block. That means channels between about 0.055" x 0.055'' and 0.04'' x 0.04".
Will that really clogg?Regards, Volker
VOLKER LANDWEHR I know how the SCR works. What I don't see is the need for a DPF. And please don't compare truck and locomotive Tier 4 diesel directly without taking into consideration the different PM limits. Cat might be new to use of SCR but Cummins isn't and they use SCR without DPF too.Regards, Volker
New? What do you think CAT was using on their heavy equipment and power generation (mobile gen sets) ? SCR, DOC, DPF
Normally aftertreatment will have multiple stages, depending on what needs to be lower in the exhaust stream, HC, PM, NOx. So you have what people call a "DPF" kind of an all encompassing term that includes a catalyst for NOx, stage for oxidation, stage for PM. Generally its not a single stage just for NOx reduction.
removed.
Cat's first system was call ACERT it was turbocompounding of the exhaust stream. You had part of the exhaust after it had left the main turbo go thru a secondary turbocharger that also was used as the EGR system. It wasn't very reliable or efficient at all. Cat abandoned it 3 years and about 6 billion in research and development cost later. Today you can't give away a truck with acert under its hood. They are that bad.
Shadow the Cats owner Cat's first system was call ACERT it was turbocompounding of the exhaust stream. You had part of the exhaust after it had left the main turbo go thru a secondary turbocharger that also was used as the EGR system. It wasn't very reliable or efficient at all. Cat abandoned it 3 years and about 6 billion in research and development cost later. Today you can't give away a truck with acert under its hood. They are that bad.
What does that have to do with the price of rice?
The minutes of the Board of Directors meeting of November 17th 2017 were published. The don't contain anything about the breakdown of #907 as it was one day later.
But there is some information on break-in problems. Since revenue service started F125s encountered periodical malfunctions of the urea system. Metrolink has been working with EMD to replace all urea tanks. 907 and 908 were modified by EMD to increase the reliability of the DEF system. See page 97 of following link.
Source: http://metrolink.granicus.com/AgendaViewer.php?view_id=3&clip_id=412
That can be completely independent of the real breakdown reasons.
EntropyNew? What do you think CAT was using on their heavy equipment and power generation (mobile gen sets) ? SCR, DOC, DPF
At that time it didn't interest me if Cat was new are late or whatever to SCR.
It was an argument about the need of DPF on the F125. One of Shadow's line of argument seemed to me, that Cat got it wrong without the DPF because they were new to SCR.
My argument: Cummins designed the QSK95 for the Siemens without DPF too. And they have a long experience with SCR.Regards, Volker
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