Is DEF-T4 result cheaper when compared to the T3 reality?
The only way DEF tier 4 is going to be ‘cheaper’ is if all the other NOx “controls” are removed and the engine compression ratio and pilot injection adjusted for high performance – with the SCR/DEF system then being adjusted to knock down all the resulting NOx with minimal ammonia slip. That should incidentally at least address the microparticulate (<2.5pm) issue that is the evolving health concern with compression-ignition and direct-injection engines.
I don’t think railroads have overlooked the problems EMD had with the Spirit locomotives, and the ridiculous derating provisions that EPA seems to be mandating if the flow of DEF is interrupted for any reason. Certainly there was a woefully-ill-concealed intent to unfunded-mandate DEF on locomotives with the arbitrary numerical NOx spec in tier 4 final, and I expect the attitude continues with development of tier 5; as long as anything can be grandfathered into operating status, I think it will be preferred to tier 4 or higher compliant status – whether new-build or aftermarket.
That essentially leaves government with an alternative it has been traditionally reluctant to employ – use of incentives rather than penalties to speed the adoption of very-low-NOx operation. That might easily be to forgo some or all the tax levied on some purchasing or operations, or exemption from other government mandates such as required electrification.
In any case, much of the rationale for very low NOx in absolute amount is no longer as well-established as in the ‘bad old days’ when HC emissions were more tolerated and atmospheric HC levels higher (to give the substrates that NO2 in particular would act on to produce elements of photochemical smog). Again, what a pity this wasn’t acknowledged when EMD was essentially excluded from building new locomotives for domestic consumption a decade ago…
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CPKC has announced an order for 170 ET44s from Wabtec. The first major order for new T4 locomotives in years.
Rumor has it they will also put in an order for EMD SD70T4s. But that has not been announced yet.
this is all per loconotes.
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Well this is coming from someone very familiar with the OTR side of the emissions fight in the diesel logistics nightmare. SCR with DEF helps until the systems fail. The EGR systems alone are a freaking nightmare for maintenance reasons. Engines that used to last over a million miles before 50 percent needed an overhaul well that rates down to between 600 to 750k. Overhauls went from 10k to between 30 to 40k. Carbon and a byproduct in the exhaust becomes a small problem. The hydrogen sulphite that’s produced when diesel fuel is burn. When cooled in the EGR cooling system becomes sulphuric acid and over time just eats the entire EGR cooler and eventually you have coolant in the oil and then mayonnaise is created and bang you’re needing a new engine. And going on how well railroads under PSR maintain the equipment this is going to be a wakeup call.
A major OTR fleet near me literally has EGR coolers as a scheduled replacement item every 250k miles. It’s a 20k repair job still cheaper than a 50k motor.
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So none of the manufacturers have devised a EGR Cooler that can withstand Sulphuric Acid?
The problem isn’t just the acid that gets produced but the carbon soot in the exhaust also from diesel fuel exhaust. You’re facing a two fold problem. First you have an acid that will eat through any metal but titanium nickel or gold. But the costs for 1 of those is 2k an ounce titanium is very hard to work with nickel alloy steel is good but due to the heat difference between the EGR intake side up to 1200 degrees and coolant being under 190 it gets brittle. But then you have basically a abrasive being forced through those tubes nonstop and just wearing them away. First you get pinholes and then you’re burning coolant and getting it into the crankcase. They don’t do oil cooled EGRs for one simple reason if it failed the engine would runaway and then more than likely explode.
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Have ceramics been investigated?
The world has come a long way since prehistoric man found the iron meteorites brought to Earth. Engineers have and continue to develop solutions to all sorts of issues.
Remember the TRASH that the cars of the 1970’s were with their emission systems the stole both performance and fuel economy from their owners. Now, 50+ years later - in the automotive world we have more power and performance than we ever dreamed of back in the 70’s.
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Ceramics have been tried and failed. You need to remember what’s downstream of this one component on a diesel engine it’s the intake manifold itself then the intake valves on the head. So you’re not just getting the carbon building up and blasting the EGR cooler after it’s cooled it becomes very sticky and sticks to the intake manifold and intake valve runners. https://images.app.goo.gl/KuuXBgaFu28tWCfWA this is about what they’ve been seeing after 250k miles inside the intakes and while they have it torn down they clean it all out.
DEF does not improve fuel economy… DEF is used to remove NOx.
What is the ‘specific’ fuel economy of equivalent locomotives -
Tier 3
Tier 4 w/o DEF
Tier 4 w/DEF
How much DEF is required per gallon of diesel? How much is the price of DEF in bulk as would be required for railroad size fuel tanks?
In the CSX Locomotive Management System, when I was working, the ‘Heavy’ AC engines were rated at a nominal 5 gallons per mile when used in ‘heavy haul’ service (bulk commodity, max tonnage unit train services). T4 engines arrived after I retired and I don’t know how those are rated in comparison.
As I understand it, there are no orders being placed by class ones because rebuilding is far cheaper due to tier 5 EPA requirements for new builds. Rebuilds bypass these requirements.
Most OTR industry trucks carry a 20 gallon Def tank which is good for about 250 to 300 gallons depending on idle time engine loading and other parameters. The new Amtrak locomotives carry 125 gallons on board for their needs. It’s normally about a 10 to 1 ratio you burn 10 gallons of diesel and you need a gallon of def in the current models. It used to be higher usage but testing proved more was wasteful. The biggest problem with DEF is that it’s still corrosive as hell having a PH under 4 it freezes above 40 degrees Fahrenheit and it’s expensive to get. But beyond that it does work if you willing to deal with sensor issues injector failures derating engines and a myriad of other issues.
Please read what I wrote. I did not say DEF improves fuel economy. I said DEF ALLOWS a Diesel engine to match Tier 3 Fuel economy and still maintain it’s Tier 4 rating.
I appreciate Balt’s ask of just how much as that’s a question rarely asked in my estimation. It’s just taken on faith that it is sufficiently better to matter.
Also, we can only go so far with comparisons to OTR trucking. A medium speed 4400HP diesel is not exactly the same as a typical OTR engine. TO say nothing of a Two Stroke such as the 710.
Even the experience with the “High Speed” Cummins QSK95 isn’t going to be a 100% accurate comparison.
I wonder if anyone has looked at the DEF 710s that NS has or that are running in Marine service and done a comparison?
There’s enough ISX engines in marine service that Cummins would have a clue as to what’s required also Progressive aka Caterpillar isn’t going into this blind either. At Caterpillars Mosseville engine production plant they have enough test cells they literally can test for anything that might be considered. They literally weigh everything that goes into the engine prior to the testing and everything that comes out of the engine afterwards. They literally weigh the test filter papers for the exhaust systems to catch the soot in the exhaust.
They’ve got test cells from their smallest engine the C3.6 to their C175
I’m sorry was this meant to be an answer to something?
None of that addresses the question asked.
Yoho the C175 is literally the same engine that is used by EMD in their passenger engine they sold to Metrolink a few years ago. They bought 40 F125s all equipped with DEF DPF and SCR in 2017. So they’ve been used by railroads in real world service prior to Amtrak getting the Charger series of locomotives by at least 5 years. These carry 1800 gallons of fuel and 265 gallons of DEF right off the spec sheet.
https://www.progressrail.com/en/Segments/Locomotive/Locomotives/PassengerLocomotives/F125.html
So based on that ratio its about 6.7 gallons of fuel per gallon burned per gallon of DEF needed.
Your comment is implying such, as was a previous comment on this thread from August… DEF has nothing to do with fuel economy… Now if you would have stated, eliminating EGR, and DPF improves fuel economy, then that would be correct. As it is those items that hurt fuel economy… You mentioned months back in this thread, a 710 with DEF, would get good fuel economy… Yes because it has no EGR, DPF, or DOC…
Now with the Chevron Doctrine overturned, a better route would be for Wabtec, and Progress to take the EPA to court over T4, winning litigation reverting back to T3…
No it does not. A 710 with DEF gets better Fuel economy than an 1010J with EGR and DPF because EGR and DPF require it to operate in a less fuel efficient way. One does not need to imply that DEF is ipso facto increasing the fuel economy for my statements to make sense. I never said that.
But what does the C175, another high speed diesel have to do with the question asked?
I made the point that High speed diesel behavior with DEF is not a perfect comparison to large medium speed diesels. So the QSK, and C175 are not the comparisons I was interested in. The 710, the 1010, The FDL, HDL, GEVO are medium speed diesels. There are others. But the C175 and the QSK are High Speed diesels. Not a perfect comparison…at least I don’t know that they are.
Also, knowing what tools Cummins and Cat have to test their locomotives doesn’t anwer any questions. I know they have the tools to test this. EMD had a T4 710 test engine in the mid 2000s I believe.
Any diesel engines that use EGR only to meet emission standards aren’t as efficient in terms of engines that use SCR with DEF in combination. I just look at the OTR industry for proof here. The entirety of the engines produced between model years 2007 through 2012 when DEF and SCR introduced into the industry here in the USA and Canada literally finding one of them on the road is next to impossible. There’s more middle 80s through 90s equipment running around in the OTR industry than those 5 years of equipment.
Why fuel economy dropped between 15 to 20 percent and it took getting DEF with SCR to regain just 10 percent of the lost fuel mileage. The best MPG the the industry ever got was in 06 the year before the EPA tier 4 emissions hit us. 18 years later base fuel consumption is still 5 percent lower than what they got 18 year ago. Yes MPG is up overall thanks to aerodynamic improvements but fuel burn per HP produced is still 5 percent more. Someone bought a 22 T680 with a blown Cummins ISX in it. They put into the engine bay a remanned 14 liter Detroit Diesel from the 06 model year without any emissions equipment on the engine. They are leased to a company named Quantix near me. They are getting 12 MPG hauling an acid tanker. The standard T680 In this fleet doing the same job gets 8.