I have seen several General Electric DASH-8 and DASH-9 locos that have burned paint beneath the exhaust stack.
What events have to happen for the paint to be burned off the on the sides of the GE diesel locomotives?
I think it’s a bit different from what BaltACD posted (which is a stuck injector or lube leak into the turbo causing that kind of rich black smoke that turns to flame when it’s ignited). I think what burns the paint is liquid blowing out of the stack, like after a massive turbo seal failure, that then falls and runs down the side of the hood ignited. Perhaps there are other dramatic failures (like the breakdown of the JB Weld repair at Lac Megantic) that would produce fire that dribbles down rather than pluming up…
I remember as a child being driven past a three-unit consist of GEs idling in Forrest Yard. No more than half an hour later we came back the other way and the middle unit was forlornly sitting with all the paint burned off those three doors. No smoke, no foam, no people running around … but in that short a period of time the damage had been done.
I’ve also seen a couple of videos where there was visible flame inside the hood when the doors were opened, although I don’t think that’s the principal cause of the specific damage you mentioned.
Does the fuel become a solvent at high temperatures or are there flames blowing down the sides?
Will the engine have to be taken apart to find the cause?
When you see flame coming out the exhaust of any internal combustion engine it is indicative of uncombusted excess fuel in the exhaust and it is being burned at atmospheric conditions, even then the excess fuel, being heavier than air can fall onto the carbody and be ignited then and there. Since diesel locomotives exhaust virtically from the top of the unit, excess fuel despite being raised into the air by the exhaust volume, will fall due to gravity.
I am guessing that burned carbody panels are indicitive of engines that have been exhausting and burning excess fuel for a period of time.
It’s flame that causes the observed effect. Note how the edges of the unaffected paint look – often blistered – and the characteristics of the metal that has been exposed. If the paint had been ‘stripped’ via a solvent effect this would all be very different.
I have seen a couple of these (and I think we saw one pictured in a fairly recent thread) where the ejected lube did not catch fire – black ‘dip’ all over the stack and running down the doors to the running board.
Turbo sits up under the stack, and it is pretty clear what has happened. There is probably no need to go into the engine ‘analytically’ to determine what that problem is (although it might be necessary to clean out any of the lube oil that ran down into the manifolds etc. – not all of the oil that leaks goes ‘up and out’.
Note that a lube failure like this is probably on the turbine (exhaust) side. If the leak were into the compressor side, the engine would likely overspeed (or effectively overfuel) as it will ‘run’ on a certain percentage of engine oil in the intake charge via compression ignition even though Not Very Effectively. I’d expect to see torching like Balt’s picture if this happened – but I’m going to leave it up to the railroaders, Randy Stahl in particular, to describe what some of the actual causes of severe ‘wet-stacking’ in 7FDL engines are.
Diagnostics for problems originating in the actual engine, like injectors, I think, involve consulting the computer (you can tell which cylinder(s) are misfiring to guide you to where the problem is) but I don’t know how much more engine work is needed when something lets excess oil or fuel into the ‘works’, for example if a broken injector were to let diesel fuel dilute the lube oil and fill up the crankcase to the point the tribology (or seals) of the turbo bearings got compromised.
The top is for an EMD engine/turbo/exhaust fire because the stack is up front? The remaining ones are for GE’s with the stack towards the back?
That is a great explanation of the details.
Thanks.
I don’t believe the burned “sides” or doors are from stack fire/turbo fire.
GE engines have high pressure fuel pumps and lines on the outside of the engine. They had many issues with pump lines breaking, bolts sheering, shops not installing the lines correctly etc.
Examples:
http://trn.trains.com/news/news-wire/2012/11/general-electric-tier-3-locomotives-suffer-engine-fires
TSB Canada investigation into Locomotive Engine Fire (P42DC)
http://www.bst-tsb.gc.ca/eng/rapports-reports/rail/2009/r09h0010/r09h0010.pdf
BINGO!
If you see GE body panels scorced like that, it is from an internal fire, not some external exhaust flames! GE’s are notorious for catching on fire from broken fuel lines and such. I had one do it sitting still while waiting for traffic to clear up.
I very seriously doubt that in the photo below the engine is on fire at all. Looks more like a dead cold engine start to me. If you have never seen a dead cold GE try to start, well, you would liken it to a smoke screen from a WWII Navy Destroyer!!! If you can finally get the thing to start, they will just sit there and ping on one cylinder forever. Then a second cylinder will start firing, then another and another. You would think the whole world is on fire before it gets warmed up enough to have a clear stack! People will be calling the law and the fire department will be on your tail before you can get out of town. [(-D]
Ya know, if all diesels put on a show like that people wouldn’t miss steam engines so much!
Might make for a lot of new railfans too!
Reminds me of veteran Erie engineer Jim Kostibos’ saying that the most important accessory on an ALCO PA was a fire extinguisher. He hated the things.
Who knew?
I think I want the new model of a GE locomotive with the “Diesel cold-start” sound effects in the decoder together with the heavy-duty smoke unit. If I exhibit this at the next model train show, the kids will go nuts!
To me, the KCS ES44AC looks more like a prime mover runaway than anything else.
Yes indeed, here’s the link to the original photo with a nice little description of the incident. Lots of GE-bashing comments on there too.
Back to the burnt paint subject, the FDL engine is notorious for its ability to puke oil into the exhaust manifold, stack and then all over the top & sides of the locomotive, regardless of whether this is fuel oil or lube oil that originates from the cylinders or the turbo. Most of CN’s Dash-9 fleet has patched paint or burn marks on the roof around the stack from the fire that inevitably originates when the enough oil builds up to touch something hot enough to set it ablaze and then poof!, the whole thing goes up.
EDIT: I remember one particular Dash-9 that had covered its rear windshields and walkways (not to mention roof) with black splotches, and I got oil all over my boots and coat from walking back to cut if off from the train, and again later to set the handbrake for my Engineer.
Fires caused by cracked fuel lines tend to be larger and more spectacular, and not confined to the exhaust stack/roof area either.
Doesn’t look like anything running away to me. Looks like no one is concerned about what is going on as the is no sign of said police, fire department or even any railroad workers.
Whatever is going on, it’s internal and won’t blister the paint.
I thought that’s exactly what Diesel Engine Runaway was. I wouldn’t want to stand next to it either since once it overspeeds it could blow up and throw chunks of parts everywhere, like this Dash-9 that threw a piston through the roof of someone’s house. While this was not a diesel runaway incident, you get the idea.
http://talk.newagtalk.com/forums/thread-view.asp?tid=165984&mid=1190655#M1190655
As I said, it is obvious, from looking at the lazy exhaust smoke, that this engine’s rpms are not through the roof.
I don’t know about that, and these other pictures taken the same day tell a different story. Doesn’t look like it blew up, but that exhaust doesn’t look so lazy and the fire seems a bit serious for a cold start. Both photos are tagged KCS 4688 “diesel prime mover runaway” but rrpicturearchives doesn’t want to open for some reason so I couldn’t get any more or post good links to them.
Welp, wasn’t a cold start and it didn’t burn the paint off, so, it stayed internal. I wonder if anyone actually tried to starve the thing of air and limit damage?