When a turbo fails in service it is usually catastrophic. Depending on the application and configuration of the engine one type of failure is more damaging than another. With most turbo failures there will be a massive amount of oil ingestion into the after cooler if equipped or worse right into the intake manifold and get burned uncontrollably by the engine until further damage is done. A compressor wheel failure will flood the air intake with metal fragments. A turbine wheel failure will cause an almost suffocation of the inlet air and exhaust system and is typically seen as tremendous amount of smoke if the engine keeps running. Some turbos are cooled by the cooling system and any one of these failures can cause coolant leaks and contamination of the oil and air intake.
Way back in diesel school I saw a movie put out by Detroit diesel ( the little brother of EMD). They had an inline 6-71T running on a dyno with no air filter. At 2000 RPM under load a person through a table spoon of fine dirt into the air intake and the whole side of the engine exploded with a great fire ball and shrapnel flying in every direction. Even the camera was destroyed.
With out knowing the type of failure its just a guess on whats happening with the GEVOS. With the high RPM of a turbo and the tremendous strain of the compressor and high heat of the exhaust side any type of failure can be instantaneous and any shut down safety appliance will be too late to be effective. When a Cat C15 diesel engine is working under load the turbo can be spinning at 60 to 70 thousand RPM. Exhaust temps can climb to well over 900 degrees and boost pressures can be as high as 40 PSI. Running trucks on the chassis dyno I have seen the turbos glow cherry red and some have turned bright cherry almost white.
Pete
I pray every day I break even, Cause I can really use the money!
I started with nothing and still have most of it left!
bubbajustin When a turbo goes, does it completely stop the locomotive from moving? Or can it still move, but with less horsepower? What does it look like when one blows? Thanks for answering my questions! Justin
When a turbo goes, does it completely stop the locomotive from moving? Or can it still move, but with less horsepower? What does it look like when one blows?
Thanks for answering my questions!
Justin
Ok, that makes scince!
Thanks!
The road to to success is always under construction. _____________________________________________________________________________ When the going gets tough, the tough use duct tape.
tomikawaTTHas anyone considered establishing a maximum operating time for railroad turbochargers?
-Don (Random stuff, mostly about trains - what else? http://blerfblog.blogspot.com/)
If I were an engineer at GE here is how I would proceed with solving this problem.
1. Request all operating RRs to temporarily park as many of the affected units as possible and bring other units back in service ( thank goodness for the recession).
2. Has this turbos been installed on other units in the past?
A. Are they being used differently. a. different electronic programing b. higher exhaust temps c. higher airflow inlet or outlet. d. other imput or output differences e. any upgrades for this application?
B. Have these units failed in the same way on other types of locos?
3. A new turbo what are the design differences?
A. Are all failures the same?
B. Fatigue analysis and testing of critical parts?
C.. Why is containment casing not holding together when a failure? (safety item)
D. If failed part made by more than one vendor is it both vendors or not?
E. Get metalurgic analysis of failed part
F. Redesign turbo if necessary.
G. Replace suspect turbos.
Although this is only a partial flow for solving this problem I hope you get the idea?
blue streak 1 If I were an engineer at GE here is how I would proceed with solving this problem. 1. Request all operating RRs to temporarily park as many of the affected units as possible and bring other units back in service ( thank goodness for the recession). 2. Has this turbos been installed on other units in the past? A. Are they being used differently. a. different electronic programing b. higher exhaust temps c. higher airflow inlet or outlet. d. other imput or output differences e. any upgrades for this application? B. Have these units failed in the same way on other types of locos? 3. A new turbo what are the design differences? A. Are all failures the same? B. Fatigue analysis and testing of critical parts? C.. Why is containment casing not holding together when a failure? (safety item) D. If failed part made by more than one vendor is it both vendors or not? E. Get metalurgic analysis of failed part F. Redesign turbo if necessary. G. Replace suspect turbos. Although this is only a partial flow for solving this problem I hope you get the idea?
Never too old to have a happy childhood!
No it is simple FORCE appiled. Most Turbochargers and GE uses a true one all the are is a shaft a compressor wheel and a Turbine wheel mounted on a set of bearings with an oil supply mounted in an extremely close tolorance HOUSING. Now the exhaust from the engine hits the turbine wheel and spins it and on an OTR truck motor they can spin up to 70k-100K rpm I imagine that GE's is in that speedrange. I had one shaft failure while driving under full load The turbine housing section made out of cast moly steel went THRU the hood of my 1997 Peterbilt 379 like it was not even THERE leaving a 3 foot hole in the side of the hood. The compressor section made from Alumimun took out the Oil filter mount and oil cooler with the shrapnel it had made. All the shop said is what the hell happened CAT was like we have never seen one let loose like that. They found a sliver of O-ring blocking the feed line to the turbo and it had gotten hot and eventually crackd off. The thing had run like that for close to 500K before letting loose but when she did LOOK THE HELL OUT.
If it is the shafts that are failing there is only one way to get rid of the problem replace the whole assembly. Turbos have to be balanced as a rotating unit do you want something out of balance at 70K RPMs I think not they would tear themselves apart faster than for us WW2 buffs the Japanesse planes BLEW UP.
Ed in Shelbyville
Work train GEVO July 26, 2009. It rained last night and the fog hadn't burned off yet when the photo was taken.
creepycrankNone the less blue streak layout the engineering process necessary to solve the problem. GE will have to consider a redesign of the casing or a scatter shield before the railroads install their own. The present design must be pretty close to the ragged edge to require very careful manufacturing methods.
If it is the shaft that is failing-----WHY is it failing? If the shaft is not robust enough it may require a thicker shaft. Then the bearings, wheels, turbines, lubrication, etc may all have to be redesigned.
If a shaft of different metal with the same dimensions can be used ---stilll all the above items will need to be considered but not necessarily required. Intermetal interactions need to be considered ( extreme example not applicable here copper--aluminum)
I agree with you Pete. We also had a rash of Mack turbo failures years ago at big brown. Now a days it is IHC variable turbos that fail due to coked up unison rings,but they are not blowing apart. Cat quit the truck line to concentrate on the expanding need for earth moving equipment in places like China. These engines need not meet the U.S. EPA standards not to blow smoke on the highway.
SSW9389Yesterday the wife, grandaughter and I took one of our cats over to the county clinic to get its shots. At the Kentucky Street crossing here in Shelbyville sat an NS work train in the siding. An NS GEVO #7552 was power for this nine car work train. I have to wonder if the unit has been downgraded to work train service while this turbo issue is being worked out. It seems kind of strange to have a high capacity, high dollar unit on a nine car work train, but it makes better sense to use it for that than to park it. Ed in Shelbyville
That is not the reason at all, The NS is taking engines out of service as needed to check them out the reason for this engine on a work train is it was probley the only one around free for duty, and the air condition is nice for the crew. on the NS it dont matter what engine is on a work train and ive seen dash 9s or sd 70 on work trains while heavy thru frieght recieve a couple of sd40 and maybe a gp 38 to work with a sd 60. the ns only rule right now is that if you have a gevo junk GE engine you are not to walk out to other units while engine is loading. Other wise its buisness as usual.
Can GEVOs be run with the turbocharger cut out?? If so at what HP?
blue streak 1 Can GEVOs be run with the turbocharger cut out?? If so at what HP?
Not effectively. One would likely lay down more smoke than an old Alco 244!
Mike
The memo we got here on the Pokey stated that GE claims (2) GEVO locomotives suffered turbocharger failures that resulted in the turbine leaving the turbocharger housing than exiting the locomotive body.
We are now advised to not walk past a GEVO unit on the walkway while the engine is loading in #1 notch or higher.
This included all NS 7500 and 8000 series units.
Collin ,operator of the " Eastern Kentucky & Ohio R.R."
blue streak 1Can GEVOs be run with the turbocharger cut out?? If so at what HP?
I might run but it would not be legal as it would not meet emissions regulations. You won't see any non-turbocharged EMDs built anymore either.
UP has found 194 GEVOs that will need their turbos replaced so far, with more to be inspected.
A diesel locomotive can still be operated without an operable turbo,but will of course have less h.p. .
Most GE locomotives have boost from the turbo from notch #5 to #8.
You can really hear the difference in the loco. cab when you go from #4 to #5.
And a bad turbo will sometimes make a thumping noise and a shake that can be felt.
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