A BNSF Coal train experiences a problem on Mullan Pass in April 2018. A brief description is in the video. Hope you enjoy, like comment and subscribe, Thanks For Watching! Video was taken by me, mtrrnick.
ElectroMotive Diesel (EMD) should include THIS in their sales campaigns, EMD locomotives doing what they do best ... after that crewman's "We can't do that." THIS is why I love railfanning EMD locomotives, they've never had "GIVE UP" as a throttle setting.
@@TemplarKnight1177 It all comes down to wheel control. You can only control the power input into a DC motor so the motor will speed up if the traction is broken and thus it acts like a drag car peeling out. An A/C motor can be speed controlled so that you can dynamically adjust RPM along with power to keep the wheels from breaking traction. It's a dance that has a feedback loop to tell the unit when the wheels are slipping. This feedback and dynamic control allows the motors to push the traction all the way up to the maximum limit allowed by the friction between the track and wheels. They are far more common now than back in the day mostly due to high power semiconductors allowing for extremely high power inverters (the units provided the variable frequency A/C to the motors). DC is more robust in terms of overload but the engineer must manually ride the throttle to prevent wheel slip whereas the A/C units can do it automatically.
This was really, really impressive. You could see the frames flexing upward as buff forces started happening while all 3 sets of engines starting working. The engines here were almost maxed out, but going backward, then grabbed rail, then went backward, then again grabbed rail a few more times, then finally got a "good bite" on the rail and moved forward. Stop and imagine how incredibly strong those pinion gear teeth have to be on those traction motors--each little tooth--to bear all that stress of pulling and pushing all that massive weight uphill. That's what really blows my mind here--yes, the engines sound great, but those traction motors are getting pushed to their limits, and the teeth on the wheels are just slowing grinding it out. I can't believe anyone can make steel that strong, but EMD and GE do, and we see it here. Just amazing.
Wow! Love I found this . Love MRL and the maned helper teams . Had a trip all planned to go to Helena and watch The Boys live . Then the stupid pandemic hit . Modeling MRL in Kansas lol. Doing an Epic Covid-19 Build in O-Gauge. Made huge mountains in recent months for my rendition of the grade. Fascinating watching the crews work to start that massive train on grade . What a delicate dance lol . Thanks for the video!
@ floodedcar 123. That is "wheel creep" - the wheels are just on the verge of slipping and are at maximum adhesion. The sophisticated wheelslip equipment on modern locos allows this condition for maximum pulling power. The wheels are actually turning just slightly faster than if they were not slipping - hence the squeal. You will hear it on all EMD "Super Series" locos too when starting at full load.
Or...was that a reference to the constant blast of air from near the front of locomotive 4311? Because it annoyed me. Reasonably sure it was from a safety valve on the loco allowing air to escape because the compressor governor is not working properly.
I got creep n peak on. I’m 32 tons on a 2 percent grade. I got 850,000 hp tractive drive to dah rail and full inter axel wheel lock deployment and sand spreader at the ready. Watching for a flash up in engine room. No notch 8 til movement spare the knuckle. Let’s spool up please maximum power pulllllllllllll
SD70ACe clocks the dynomometer at about 4,500 hp. Others like the SD70MAC at the tail end of the train generate about 4,000 hp. I think that lone GE unit up front puts out about 4,400 hp. I suspect (but don't know for sure) that even the 4,000 hp SD70MAC generates more tractive effort than the GE C44-9W. Yeah, I'm biased toward EMD and have been since I was a kid. I'm 69yo now.
Am I hearing wheel slip or the traction sanders? It kind of sounds like when you were a kid and you'd drag a metal pipe across asphalt... Or maybe I was just a weird kid. 🤣
Starting from a stop on a very steep hill with a very long and heavy train, plus the front engines were not connected at the time as a coupler broke part way between these middle helper engines and the front engines. You could hear all the locomotives wheels slipping even when they were dumping sand onto the tracks for extra traction.
@@stretchlimo7275 because I’m on a 2 percent grade with 32 ton dead weight I got 850,000 hp tractive drive to dah rail and inter axel wheel lock deployment and sand spreader at dah ready. Notch 8 puuuuuuuullllll
