What causes this? (heavy black smoke emissions)

[MEC407]

You do not see a AMTRAK P42DC spewing out flame and smoke eveyday. There is a prototype for everything.

Yup, that is definitely the first time I've seen a P42 do that. I thought the onboard computers were setup to eliminate that phenomenon for the most part.

[trainiac]

I don't think onboard computers eliminate turbo or fuel injector failures--otherwise we wouldn't see newer freight GEs send flames out the stack either! I think the reason we don't see as many P42s fire up as we do Dash-9s or ACs is because 1) there are fewer of them and 2) they are in less strenuous service.

[MEC407]

I don't think onboard computers eliminate turbo or fuel injector failures

True, but I thought the computers attempted to eliminate turbo lag, which is another cause of flames, isn't it? I know I read that somewhere, just can't remember where. There was a magazine article about the P40s and P42s, and in explaining why their initial acceleration isn't as good as an F40, it mentioned that the computer does something to prevent excessive smoke, and that this limits acceleration when starting from a standstill.

While I agree that there are fewer P40s/P42s than Dash 9s or ACs, here in Maine I get to see them 8 times a day, and since the Downeaster started running in late 2001, I've never seen a P40 or P42 throw flames from the stack, and only a handful of times have I seen them smoke (and it was never the thick, pitch-black smoke that we occasionally see from GE freight units). That's why I was so surprised to see that photo on railpictures.net.

[FDL4ever]

I don't think onboard computers eliminate turbo or fuel injector failures

True, but I thought the computers attempted to eliminate turbo lag, which is another cause of flames, isn't it?

What the computers do is ramp the fuelling rate to match turbo lag, and optimize the turbo spool-up profile both at the same time. The result is that you shouldn't get the over-fuelling that causes the black smoke and flame, even if the turbo is spooling up a bit slower than it really should. . Something has to be pretty soundly wrong wrong (turbo physically damaged and hardly willing to spool up at all, injector physically damaged, clogged induction, etc. etc. etc.) to get a really heavy black cloud, let alone flames.

[EDM5970]

Back in 1975 or so, MK and the D&H came up with a system for the PA-4s. A series of air manifold pressure switches was wired into the governor, limiting fuel to the current manifold pressure. Even if the engineman wiped the throttle out to run 8, the governor wouldn't feed additional fuel unless there was enough air to make it burn cleanly.

According to the late George Hockaday, when the system was running right, you could not make smoke with the PA-4s if you tried. And all of this was done without computers. This is all documented in Chris McDermott and Norm Anderson's PA-4 book, BTW.

[emd_SD_60]

Back in 1975 or so, MK and the D&H came up with a system for the PA-4s. A series of air manifold pressure switches was wired into the governor, limiting fuel to the current manifold pressure. Even if the engineman wiped the throttle out to run 8, the governor wouldn't feed additional fuel unless there was enough air to make it burn cleanly.

According to the late George Hockaday, when the system was running right, you could not make smoke with the PA-4s if you tried. And all of this was done without computers. This is all documented in Chris McDermott and Norm Anderson's PA-4 book, BTW.

Then how come current railroads haven't picked this up and started applying this modification? It looks like it would work if tried.

[NRECer]

According to the late George Hockaday, when the system was running right, you could not make smoke with the PA-4s if you tried.

The operative phrase here is when the system is running right

The system as used on the D&H PA's was impressed upon on the fuel limit circuit of the GE governor system. This approach would not be applicable to GE road locomotives-which do NOT use the GE governor.

The Woodward PG-R governors as used on some older GE locomotives have a pressure bias feature which controls fuel delivery according to intake manifold pressure. Same concept as the PA-4's-but different hardware.

The ultimate workaround was CHEC excitation-which uses a speed sensor right on the turbo.

Of course, if the turbo is faulty-engine air filters plugged-intercoolers dirty-the end result is the same-black smoke !!!!

Let us also not forget the importance of a well-designed multiple pipe exhaust manifold.

[SRS125]

I caught a Conrail Train in Jordon, NY with 3 GE's smokeing like ALCO's. The 4th unit being an EMD SD50 Shooting Flames out of the stack and side doors got an intresting photo of this. Its funny to see becuse there are 4 guys in the cab of the lead unit and the train was ordered to keep moveing by the dispatcher to keep moveing east to DeWitt Yard at 25mph!!

[wess]

Gives a whole enhanced meaning to the term "flamer".

[emd_SD_60]

Oh well, it could be a lot worse, as seen here:
http://www.csx-sucks.com/images/pic/fire2.jpg

[amtrakhogger]

P32ACDM's, particularly the older 700-709 series were good for
flaming at the stack just after mode change. Amtrak must have
upgraded the software and/or injectors because now it it impossible
to get them to smoke or flame.

[U-Haul]

Won't a locomotive belch smoke if overloaded?
http://www.railpictures.net/viewphoto.php?id=95351

[CassFireman]

This is a govenor that has racked out too fast for the load, or the turbocharger is about to give up.

SSSSSSSSSSSSSSSSSSSSSSSSsssmokin!

[ex Budd man]

If that was lube oil the smoke would probably be more blue-gray than black!

[ENR3870]

Oh well, it could be a lot worse, as seen here:
http://www.csx-sucks.com/images/pic/fire2.jpg

That looks more like a ruptured fuel line.