GP40-2Oh, and one other thing. CAT IS going to eventually dump the 710 motor for a 4 cycle for new North American locomotives. Not immediately, but it is going to happen. I told some of you guys 3 months before GM announced that it was dumping EMD that it was already a done deal. I'm telling you now that it is a done deal that CAT will replace the 710 with a 4 cycle in the future.
And if GM had kept EMD they would have eventually replaced the 710 engine with something else, most likely a 4 cycle. They were planning on the SD89MAC with the 12 cylinder 265-H engine replacing the SD70 series in the catalog but the newer prime movers many issues nixed that and instead they further developed the 70 series and 710 engines.
The 710 series will be around at last through the Tier 3 period...
"I Often Dream of Trains"-From the Album of the Same Name by Robyn Hitchcock
GP40-2 You might not be a mechanical engineer, but I am. The unavoidable fact is that EMD's 2 cycle will NEVER have the complete combustion that a 4 cycle will have. Period. You can mitigate this up to a point, but after a certain threshold, you are not going to make the regulations. Poster edbenton knows EXACTLY what he is talking about.
You might not be a mechanical engineer, but I am. The unavoidable fact is that EMD's 2 cycle will NEVER have the complete combustion that a 4 cycle will have. Period. You can mitigate this up to a point, but after a certain threshold, you are not going to make the regulations. Poster edbenton knows EXACTLY what he is talking about.
Paul_D_North_JrBut rather than adding another battery system, why not just use the locomotive's main starting batteries instead as the 'buffer' between the variations in the exhaust turbine's output and the blower's power input needs ? I think the main batteries would have plenty enough capacity to carry the blower for quite a while when the exhaust output is low, but a higher blower output is needed - just a supervisory circuit of some kind to ensure that they don't get drained too far would be needed, I would think.
-Don (Random stuff, mostly about trains - what else? http://blerfblog.blogspot.com/)
oltmanndPaul_D_North_JrBut rather than adding another battery system, why not just use the locomotive's main starting batteries instead as the 'buffer' between the variations in the exhaust turbine's output and the blower's power input needs ? I think the main batteries would have plenty enough capacity to carry the blower for quite a while when the exhaust output is low, but a higher blower output is needed - just a supervisory circuit of some kind to ensure that they don't get drained too far would be needed, I would think.Actually, I started thinking about turbo-compounding to get more of the exhaust energy turned into useful work. Then I thought about the single cylinder research engine where they can vary the temp and pressure of the air box any which way they want and I put the two together. I'm thinking the battery storage should also be available for propulsion since the turbo can make more power than the blower would need. (hopefully)
Is the next logical step to go to a hybrid arrangement ? Replace the concrete ballast in the frame with a bunch of batteries a la submarines, so that the loco is basically running off the batteries. Cycle the main diesel engine on at a maximum efficiency/ lowest pollution RPM 'sweet spot' to recharge them as needed. Since the engine is then 'de-coupled' from having to directly drive the motors via the alternator - the batteries are an intermediate 'buffer' for the short-term or instantaneous loads* - the engine speed and other attributes can be carefully ramped up and down again without making too much smoke, turbo lag, fuel wastage, etc. Or is this carrying the concept to its (il)logical end ?
*It occurs to me that this might be one way to make GE's big locos into decently performing switchers, without their characteristic lag or delay when the throttle is opened, as compared with EMD's. A purely electric transmission should respond pretty snappily to the throttle, and the diesel engine can then come on line to recharge the batteries whenever it winds up and gets around to it - meantime, the switching can continue apace, without having to wait on the engine to speed up, as is presently the case - which I understand is to minimize the pollution during the speed-up cycle anyway.
- Paul North.
Paul_D_North_JroltmanndPaul_D_North_JrBut rather than adding another battery system, why not just use the locomotive's main starting batteries instead as the 'buffer' between the variations in the exhaust turbine's output and the blower's power input needs ? I think the main batteries would have plenty enough capacity to carry the blower for quite a while when the exhaust output is low, but a higher blower output is needed - just a supervisory circuit of some kind to ensure that they don't get drained too far would be needed, I would think.Actually, I started thinking about turbo-compounding to get more of the exhaust energy turned into useful work. Then I thought about the single cylinder research engine where they can vary the temp and pressure of the air box any which way they want and I put the two together. I'm thinking the battery storage should also be available for propulsion since the turbo can make more power than the blower would need. (hopefully) Is the next logical step to go to a hybrid arrangement ? Replace the concrete ballast in the frame with a bunch of batteries a la submarines, so that the loco is basically running off the batteries. Cycle the main diesel engine on at a maximum efficiency/ lowest pollution RPM 'sweet spot' to recharge them as needed. Since the engine is then 'de-coupled' from having to directly drive the motors via the alternator - the batteries are an intermediate 'buffer' for the short-term or instantaneous loads* - the engine speed and other attributes can be carefully ramped up and down again without making too much smoke, turbo lag, fuel wastage, etc. Or is this carrying the concept to its (il)logical end ? *It occurs to me that this might be one way to make GE's big locos into decently performing switchers, without their characteristic lag or delay when the throttle is opened, as compared with EMD's. A purely electric transmission should respond pretty snappily to the throttle, and the diesel engine can then come on line to recharge the batteries whenever it winds up and gets around to it - meantime, the switching can continue apace, without having to wait on the engine to speed up, as is presently the case - which I understand is to minimize the pollution during the speed-up cycle anyway. - Paul North.
James
The EMD 710G engine will die when EMD feels that they can no longer economically upgrade the engine to meet tighter emissions standards, or when the railroads demand more power than EMD can produce with the motor. The 265H is waiting in the wings for that day. They cannot simply drop in the current Cat diesel and expect it to work properly. I would expect that the alternator, engine control systems, and especially cooling systems would all need to be reworked. Also in the previous trials with Cat diesels problems have been experienced due to the locomotive frame flexing which has stressed the crankshaft bearings leading to premature failure. All that can be solved, but it isn't trivial.
The MaK 2-strokes survive because of the service they are used for, large ship motors without any reduction gearing to the propeller. A 4-stroke diesel has to run faster than the maximum speed for efficient propeller operation. Also I am fairly sure that the motors are direct reversing, i.e. when you need to back the ship the motor is stopped and then started such that it rotates in reverse, which is something a 2-stroke can do, but a 4-stroke cannot do.
creepycrankLet me address some of the misconceptions. EMD 710 has as complete combustion as anybody else...
No misconceptions on my part. I've worked with EMD and GE products for several decades now. The EMD 2 cycle can not, and will not have as complete combustion as a 4 cycle. Ever. With the current modifications, the EMD has good enough combustion to pass Tier 2, but it can't match the 4 cycle GEVO in emissions and fuel economy.
The only reason why the 710 is still around at all was due to GM's financial crisis coupled with the buying investments group's limited money for additional R&D with the 4 cycle H engine. If GM wouldn't have sold EMD, the 710 would have died years ago.
GP40-2 The EMD 2 cycle can not, and will not have as complete combustion as a 4 cycle. Ever
I'm an ME, too and have done lots of tests over the years on the EMD and GE locos. My impression has always been that the EMD had more complete combustion since the stack ran measurably clearer at full load than the GE. A perfectly running FDL always has a slight brown haze the the exhaust. A perfectly running EMD will always be clear.
I suspect the completeness of combustion has more to do with the particulars of the head, piston and fuel injection and less with the 2 cycle vs 4 cycle. Also the GE is shooting double the juice into the same space each combustion stroke which, I would suspect, should lengthen the time to complete combustion.
GP40-2creepycrankLet me address some of the misconceptions. EMD 710 has as complete combustion as anybody else... No misconceptions on my part. I've worked with EMD and GE products for several decades now. The EMD 2 cycle can not, and will not have as complete combustion as a 4 cycle. Ever. With the current modifications, the EMD has good enough combustion to pass Tier 2, but it can't match the 4 cycle GEVO in emissions and fuel economy. The only reason why the 710 is still around at all was due to GM's financial crisis coupled with the buying investments group's limited money for additional R&D with the 4 cycle H engine. If GM wouldn't have sold EMD, the 710 would have died years ago. GM wasn't in a position to kill the 710, but CAT is, and will.
GM wasn't in a position to kill the 710, but CAT is, and will.
This may make sense from an ME perspective, but it ignores some of the other aspects of the 710 decision. GM and EMD didn't have the luxury of letting the H engine work itself out. Even if GM had had the money, Dropping the 710 would have essentially meant giving up on the entire market. Nobody wanted the H engine when they could buy a well known product from GE. Don't underestimate that power that over 30,000 2 stroke EMD engines in the field had on sales. Updating the 710 made sense.
The same issues are still around, perhaps even more so now with orders down. Switching to a new engine in the near to medium term would be a disaster.
As for emissions, does anyone have access to the emissions information? Everything I've heard is that the 710 outperforms GEVO on emissions though obviously 4 extra cylinders means not as good on fuel economy.
Also, since there are competing statements about MaK's engine line, I looked it up, the Cat Marine site doesn't specifically say, but I did read in a brochure on the VM 43 C that it uses a modified Miller Cycle. And then Wikipedia tells me that the Miller Cycle is a 4 stroke engine concept.
An earlier post stated that Cat left the class 8 truck market, and that is true, but maybe not all due to thier difficulty in meeting EPA emissions. PACCAR (Peterbilt/Kenworth) entered the market with their own engine this year, and according to a trucking magazine I saw, PACCAR was 75% of Cat's truck market. Navistar also is selling a new engine of their own.(I am not impressed with their EGR approach, but time will tell.) I drove for a fleet that switched to Cat to avoid buying '07 compliant Cummins, and regretted every minute of it. They have sinced switched back. With their best customer selling their own engine, and the problems Cat had with the '07 engines, the decision to get out seems reasonable.
creepycrankAlright you ME (Mechanical Engineer) wannabe's go to the "Eng-tips.com" website and go to engine and fuel engineering and then to "4-strokes obsolete?" and "transonic combustion" for todays thermo lesson. For the rest of you about CAT's motive for spending all that money on EMD. CAT has tried to break into the locomotive market through MPI with the 5000MK and collaborating with EMD on low emission switchers- MP15D and MP20D I think without much success. That was before they bought Progress Rail. Since then PR has developed their own version of a genset locomotive and they rebuilt some SD50's as PR43C to test out CAT's C175 engine in actual rail service. If their plan is to eliminate the 710 engine they will have to build some demonstrators and run a full testing program for several years and then convince the railroads that they have a much better package than GE. there is an awkward problem with marine and industrial engines where CAT and EMD compete head to head. Maybe they will sell the 2 stroke business to MPI or someone but what was the purpose of buying EMD in the first place if it wasn't to get the 2 stroke market. To me it would make more sense if Rolls-Royce or Wartsila buys EMD. Rolls because they own Allison and can market a complete marine package with the Ulstine Z drive. Wartsila because they build 2 stroke engines and have experience in servicing EMD base load units in the Caribbean and other remote and primitive areas.
Good summation. Slight (and off topic) point though, I was under the impression that the EMD marketed MP15 and MP20 units were bult with Detroit Diesel(MTU) engines unlike the earlier MK1500D/MK2000D which had CAT 3500 series prime movers?...there may be exceptions as Wabtec has offered customers a choice of engines in units they have built recently..IIRC, there are MPI units operating with CAT, MTU, and Cummins engines out there...
creepycrankAlright you ME (Mechanical Engineer) wannabe's go to the "Eng-tips.com" website and go to engine and fuel engineering and then to "4-strokes obsolete?" and "transonic combustion" for todays thermo lesson.
The GP15D and GP20D (sold only to CIT Leasing) were MPI locomotives marketed by EMD for the low end of the market. Both models were equipped with Caterpillar engines. I believe that the MP20C-3's sold to Pacific Harbor Line have Detroit Diesel/MTU engines.
Yes, the GP15D and 20D have cat 3500 engines. EMD listed them in their catalog as:
3512 (EMD 12-170B15-T2)
3516 (EMD 16-170B20-T2)
The ButlerThe idea of a loco starting, stopping, and changing speed all in no relation to the diesel engine's starting, stopping and changing speed would really mess with this trackside fan's mind. It would bring another unique dimension to the joys of railroads. Just like watching MERTA's F40's stop and start with the engine speed never changing.
creepycrankAlright you ME (Mechanical Engineer) wannabe's go to the "Eng-tips.com" website and go to engine and fuel engineering and then to "4-strokes obsolete?" and "transonic combustion" for todays thermo lesson...
LOL. I actually wasted 3 minutes of my life reading that thread over at Eng-tips.com. Some hard hitting science on that thread (not!). The only posters who seemed like they even remotely knew anything about the topic pretty much stated the same issues with two cycle diesels that I have been saying all along.
You can accept this or not (I really don't care either way): (1) The 2 cycle EMD will never match the emissions or fuel economy of a 4 cycle and (2) CAT is going to kill the 2 cycle in new locomotives in North America.
What are the railroads going to do? Absolutely nothing. GE sure isn't going to waste their time on a 2 cycle design, and the railroad aren't going to stop buying EMDs when CAT changes the engine over to a 4 cycle. What purpose would it serve them putting GE's only competitor out of business?They would rather have the option of buying some EMDs, even with a different engine, for no other reason than to keep GE honest.
You guys are also missing the possibility that when CAT does replace the 710, the final product may be as good as, or even exceed GE's performance. That's something the current EMD design can't do.
Can someone give the actual emissions figures for the 710G3 T2 and the EVO?
A bunch of Mechanical Engineers fighting like big horn sheep may be amusing, but there are facts to be had on this and it would be nice to see them. Posturing about who the better engineer is is useless.
YoHo1975A bunch of Mechanical Engineers fighting like big horn sheep may be amusing, but there are facts to be had on this and it would be nice to see them. Posturing about who the better engineer is is useless.
This whole topic reminds me when GM decided to sell EMD in the first place. Everyone in the industry who works with locomotives knew it was a done deal, but 1001 railfans chimed in that they "knew" that GM would never sell EMD. They went on and on for months posting the reasons why, only to find out that GM did indeed sell off EMD.
GP40-2The only posters who seemed like they even remotely knew anything about the topic pretty much stated the same issues with two cycle diesels that I have been saying all along.
oltmanndGP40-2The only posters who seemed like they even remotely knew anything about the topic pretty much stated the same issues with two cycle diesels that I have been saying all along.Which is your less complete combustion claim? Are you backing away from that now? I didn't read a thing, nor do I know of any evidence that supports this claim of yours. You gotta show me something other than your opinion.
In Israel, the railroad seems completely sold on Alstom double-end streamlined diesel-electrics, with EMD prime movers, probably 710's. Anyone know why?
GP40-2Besides, why are you asking me for 710 emission data?
The H engine was developed for two reasons. One, because it looked the the industry was headed toward 6000 HP AC locomotives and a 20 cylinder 710 didn't look like it could do much more than the low 5000s. Second, because fundamentally, a two stroke can't match a four stroke in efficiency. Fuel efficiency was the name of the game in the 80s and 90s. GE always held a couple of a percent advantage over EMD.
Emissions regs changed the game.
soilredneckAn earlier post stated that Cat left the class 8 truck market, and that is true, but maybe not all due to thier difficulty in meeting EPA emissions. PACCAR (Peterbilt/Kenworth) entered the market with their own engine this year, and according to a trucking magazine I saw, PACCAR was 75% of Cat's truck market. Navistar also is selling a new engine of their own.(I am not impressed with their EGR approach, but time will tell.) I drove for a fleet that switched to Cat to avoid buying '07 compliant Cummins, and regretted every minute of it. They have sinced switched back. With their best customer selling their own engine, and the problems Cat had with the '07 engines, the decision to get out seems reasonable.
Cat is not entirely out of the class 8 market, everything from the head gasket down on International's Maxx Force 16 is Cat. International actually does not want to build this engine, but the market still demands a big bore engine for the power hungry truckers.
The big reason, in my humble opinion, for Cat leaving the market was that they made the emissions control system too complex, as a small part failure could sideline the truck. I work for a midsize trucking company, the '08's and '09's we bought were sent back after about a year, they were spending more time in the shop than on the highway. Newest batch of trucks now have Cummins engines, and both shop and drivers are now very happy.
Now, back to topic, I don't see Cat dropping the 710 like a hot potato anytime soon. The 265H motor has not been perfected for North American operations yet, and getting the Cat motors to work with EMD electrical controls will also take time. As to which way Cat and Progress Rail decides to move in, it is really anyone's guess. My best guess is that we will see a few new demonstrator models within a few years, testing, checking, and rechecking everything, until it will be ready for production.
Randy Vos
"Ever have one of those days where you couldn't hit the ground with your hat??" - Waylon Jennings
"May the Lord take a liking to you and blow you up, real good" - SCTV
daveklepper In Israel, the railroad seems completely sold on Alstom double-end streamlined diesel-electrics, with EMD prime movers, probably 710's. Anyone know why?
Israel Railways has always favored EMD power for their Diesel traction. They rostered a variety of EMD G series export locomotives with 567/645 prime movers. so when they spec'd out their newest locomotives from Alstom it's not surprising they wanted EMD engines and electrical systems..
oltmanndThe H engine was developed for two reasons. One, because it looked the the industry was headed toward 6000 HP AC locomotives and a 20 cylinder 710 didn't look like it could do much more than the low 5000s. Second, because fundamentally, a two stroke can't match a four stroke in efficiency. Fuel efficiency was the name of the game in the 80s and 90s. GE always held a couple of a percent advantage over EMD. Emissions regs changed the game.
This is exactly what I was thinking.
The H engine was developed to compete in the 6000HP market. The expectation was that that was where the industry was going in the 90s. That didn't end up happening. Once that didn't happen, the entire reason for doing the engineering on the H engine would have mostly disappeared.If the 6000HP need hadn't come up, there is no way GM would have funded H engine dev. I don't need to be a Mechanical Engineer to understand fundamental R&D funding concepts. if the 710 would do the job, you don't spend a dime to develop a replacement. GM would never have spent the money. They would have expected 710 to last just as long as the 645 and 567 did.
In the mean time, Tier 2,3 and 4 appeared which is a different engineering challenge. I don't have access to EMD's emissions numbers, I would like to see them, because Argonne, the lab working with EMD seems to think the 710 is great on emissions and word on the street has been very positive as well. I'd like to see some proof.
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