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  • Stopping a reluctant or runaway diesel engine.

  • General discussion about locomotives, rolling stock, and equipment
General discussion about locomotives, rolling stock, and equipment

Moderator: John_Perkowski

 #868844  by RickRackstop
 
In another forum we are discussing ways to start a reluctant engine and its come up that there are also problems getting them stopped. Locomotive engine air intakes are too big to throw a rag in it to block off the air. On drill rig engines it is a requirement that a damper be installed to accomplish the same thing. EMD was surprised to find that their customers were putting these things on their engines and it was decided that EMD had to at least test and approved these devices. The worry is that the blower quill shaft is marginal for this type of abuse. Well the tests were okay but don't come looking for warranty for a broken shaft. On other engines I have read that in the case of a runaway engine, i.e.. engine runs on the lube oil leaking from a turbo seal, that they try to stop it with a CO2 fire extinguisher in the air intake to block off oxygen. Marine engine rooms have large fire suppression system that you would think they could tap into. GE has enough fire that you would think that they would look into this idea.
 #868855  by John_Perkowski
 
FWIW,

Quill shafts are a common point of weakness of all GM diesel projects. In my military life, I am familiar with the 6V-53, the 8V-71T, and the AVDS-1790 plants (M113FOV, M109 howitzer, and M60 tank family respectively). All of them have weak quill shafts.
 #868995  by RickRackstop
 
The blower drive shafts are made that way so that they'll break first if something drops in to the blower. Its not a problem if the oil bath filter that use to be furnished with the engines doesn't collapse internally. Sold a lot of AAF fiberglass bag type housings though, probably because it took two people to service a oil bath filter but the fiberglass bag type can be done by the ships engineer alone. The blower drives on Cleveland Diesel and Fairbanks Morse engines were much more robust making them eligible for use on submarines while snorkeling. FM owns the submarine emergency generator business exclusively for the US Navy.

Getting back to the subject at hand, most if not all 4 stroke engines would be subseptable to running away if the impeller oil seal fails and the oil goes into the intake manifold. If a turbo fails on a EMD you get no air even if the seal is wiped out and the engine can't run. This happened at an engine at Maine Yankee and the engine stopped alright but they forgot yo shut off the soak back pump and filled the airbox with 300 gallons of lube oil. Had some fun getting that cleared out. On the railroad units its usually obvious that something gone seriously wrong and with a CO2 system it would be easy for the crew to stop the engine before it self destructs.
 #869108  by Jtgshu
 
There were 3 great videos on youtube (well, not great to the railroad I guess) of BCR 4649, a GE locomotive, that was a runaway diesel.

Unfortunately, the vids were removed by the author, and they are no longer available. But it showed the loco running really high RPMs, with the mechancial forces trying to clog and block the air intake with fire extinguishers and of course, tried every other way on the loco to shut the engine down (EFCO, pulled knife switch, etc). As the clip continued, you started to hear more and more knocking and while the videos didn't show the seizing of the PM, it was noted that it ran for a little while longer til it self destructed, but as the videos progressed you could hear how the sound of the engine got worse and worse.
 #869508  by CN Sparky
 
RickRackstop wrote:On the railroad units its usually obvious that something gone seriously wrong and with a CO2 system it would be easy for the crew to stop the engine before it self destructs.
You might think that... but when it's spinning in excess of Notch 8 on its own lube oil... screaming bloody murder... things aren't quite so easy. Most crews won't touch anything other than the stop button, and even that's a stretch. Even shop crews get baffled when things go awry... not exactly "business as usual"... and 'thinking' is apparently over-rated for most of the union boys I work with.

I've seen two GE units now burning the lube oil... one was a CP at the Coquitlam yard, the other the aforementioned BCOL in Prince George. Both sets of videos that were previously available are nowhere to be found. Too bad... damn things looked like Mount St. Helens out the stack!! Quite a sight...
 #874764  by GSC
 
Speaking of the dampers above, why wouldn't GM / EMD diesels have the same emergency shutdown damper I had on my lowly '68 Diamond Reo with a Detroit 6-71? It was on the blower elbow, and if you pulled the shutdown knob, you'd have to reset the damper before you could start it again.

Seems like a simple safety solution.

Are locomotive diesels subject to running backwards? You'd probably have to stall it for that to happen. Just curious if it ever does happen. (I had both my Diamond Reo and my Mack running backwards a time or two)