Wheel Slippage

[Anonymous]

I hear that wheel slippage is not good for the modern day (probably older engines as well) computerized engines. Just exactly what does wheel slippage affect on an engine? Are there certain parts that are affected more than the other? What is the most critical damage that can be done?

Larry

[Jackflash]

For one thing, if the train isnt moving it'll
burn a hole in the rail. jackflash

[wabash1]

Let me see if i can answer this with proper sentance structure, capital letters, and proper grammer.

Depending on the type of engine i am using, That is when I pay attention to the wheel slippage. The sd 40s Gp 38 when pulling with these engines as long as you are moving the engine is not being hurt. I have been switching in the yard using a Gp 38 the wheels slipping and get another notch to increase the speed and is does. There is no burn marks on the rail and no damage.

Now lets go to the road, The dash 9s even think they are going to slip will drop the load. Then start loading back up. The new computorized engines will drop the load, The older engines would drop the load but only after a big slip. ( at least on the engines i have run).

The biggest problem with wheel slip on newer engines is the fact that when you are pulling hard, and you get a wheel slip, the amps go to zero. Then they load up again. during this time of loading back up the slack in your train has run in, and while the slack is on its way out you start loading and pulling hard again. this is when you get a knuckle. If these new computorized engines would only reduce slightly the amps instead of dropping all amps this wouldnt happen.

This is only one aspect of what happens. drawbars take a beating also, I wont comment on forces on traction motors as I am not in the mechanical department. I am sure there is some damage on the dash 9s due to the computors, ( I dont see sd40s gp 38s some of the older GE 4axel engines replacing traction motors) As well as the Sd 70s.

[Anonymous]

hey wabash, about the only thing that can to the traction motors is stripping the pinion gear. then the mechanical dept. has to go out,cut the gear case off and cut off the gear. then the electrician disconnects the motor leads and tapes them up.

[Anonymous]

Who is whining about sentence structure, J? Who cares! You probably have forgotten more about RRing than the whiners will ever know!
Ken

[dekemd]

So if I understand you right, the newer computerized engines cut power when wheel slip is detected. Does it cut power to all axles or just the one that is slipping or it thinks is going to slip? I'm with you, it would make a whole lot more sense to reduce the amps instead of cutting them completely.

This also may explain why so many knuckles get broken when trains come out of the local yard here. It's a pretty good grade coming out of the yard. They had so many stalls with the AC4400s they started adding an extra engine up front for the long coal freights and helpers on the rear for many others. A year or so ago they tore a coal hopper apart. The knuckle and drawbar stayed together, but it tore the whole assembly along with the bolster and truck clean out from under the car.

Derrick

[wabash1]

I may be wrong but when i watch the monitor screen. it shows all traction motor and the main generator isnt putting out either. so i figure the computor stops the voltage from the generator. ( or altanator ). just telling what I observe.

[edblysard]

Hey j, an Derrick,
Our motors, MK1500Ds, have slip technology. When one axel starts to slip, the "computer" cuts power to that traction motor only, and reduces power the other, dosnt zero amp them, just reduces it.
Our newer engineers let the computer take care of wheel slippage, but the old heads will throw a little sand down, cut back a notch or two, and the problem goes away.
Stay Frosty,
Ed

[Mookie]

Questionable here...

Is MK - Morris-Knudsen and also - what vintage are they (age-wise)? Seems the more I ask, the less I know!

Jen

[wabash1]

Ed this might be a good place to exsplain what wheel slippage is also. Wheel slippage is just that a little slip of the wheel might be 2 inches of the wheel. if i was pulling and the wheel just for a second loses traction it might out of a 50 inch wheel 2 inches might slip leaving 48 inches still doing its thing. its not like spinning tires on a car.even though this can happen on engines also and has happen to me on the older sd 40s be running along and start pulling up a small hill in the rain be going 45 mph and few seconds later look back at the speed recorder and be doing 75mph. drop a notch it catches and goes. Now the newer computorized engines are supposed to take care of this for us. but they seem to just drop the load. sanding on the new dash 8s and 9s also quit at 12mph. it will automaticly sand for a few seconds but you cant manually sand over 12 mph. on the sd 70s its 18mph ( i am not for sure ) Hope this clears up what wheel slip is and not spinning.

[edblysard]

Hi jenny,
Yes, MK is Morris Knudsen, now Bosie Locomotive, a subsidiary of EMD, they bought Bosie two years ago.
Our motors are 8 years old, "new" in 96.
They are number for the year delivered, and then the order thay came on property.
So the first one we got is the 9601, and the last one received is the 9624.
There were 35 of these motors build in this order, the BN has numbers 9625 thru 9635, in transfer service.
They are built using frames and trucks from GP 7s and GP 9s, and fabricated cabs and hoods, most of the locomotive parts are EMD, including the traction motors, control stands, stuff like that. They have Catipillar diesel engines, and are rated at 1500 hp, weighing 254000lbs. on standard blomburg B trucks.
If you want to see what they look like, I posted a photo on TrainCommunity.net
EMD just had Bosie build a good number for CEFX, they list them as GP20 and GP 15s, but they are MK1500Ds and MK2000Ds, just carry a EMD badge.
The 2000s are odd looking, they have dynamic brakes, and the brake grid bluge is a cross between the new EMD square style, like on SD and GP 50s, and the old, flared ones on the old GP series.
Stay Frosty,
Ed

[Mookie]

This is interesting. I have never seen slip on a diesel, but have seen it on the old steam engines. That seemed to be par for the course, if I have all my memories and information on the same "track".

Going to go mull this over and I am sure there must be a question in there somewhere!

Thanx

Jen

[Mookie]

Ed - printed this off - will go home and look at my "pitchur" book and see if any are in there. I will also go look at the website on my break.

While I have you on the line - my driver takes karate with an engineer. He is clueless about what he operates. When asked what kind of engine he runs, duh. Horsepower? Ain't no horses out there. I think I want his job! He doesn't appreciate it enough!

Jen

[Jackflash]

Jen, not unusual, a lot of engineers dont know
or care what kind of engine they are running
I know guys that cant tell the difference between
an EMD or a GE from the outside looking at it,
not all but some. jackflash

[Anonymous]

Hey Ed, which do you prefer, the SW1500 or the MK1500? Also how's those Caterpillar prime movers holding up?
marty

never got to see the demos come through roseville.

[Mookie]

Marty - going to post specifically to you in a minute - watch for it.

Jen

[Mookie]

Guess there is a real epidemic of that. Years ago, every man knew a Ford from a Chevy and most of what was under the hood. And whatever steam or diesel engine they were working. Now, a lot of them really don't care. Kinda sad.

Jen

[wabash1]

Jen

In a reply to your post i can tell you this, In my opinion i dont make me any differance weather i have 12cyl or 16 cyl on my engine. I know the differance between a emd and a ge engine i Know what the given horsepower is. so this gives me the knowladge of what the train will do/or not do. i have a book here somewhere they gave me years ago on the engines the ns has and all the neat stuff about them and since i dont have a tool box with me i cant fix them so that is unimportant. in other words i Know what is in my car and what to do to fix it. but they dont pay me to fix these engines so i wont even attempt to try. and most engineers fall into this frame of mind. hopes this helps you understand. its not that we may not want to its because there is no need to.

[edblysard]

Hi Marty,
The MK1500, visability is fantastic, great big front windows, low nose, the engineer can see you very well, they run short hood foreawd, and because they are built on GP frames, they make good road units also, BNSF uses theirs are transfer units and road units. And, they have dual cylinder brakes, with clasp type brakes, eight brakes shoes per truch, they will stop on a dime, use what you need for switching The cats have held up well, dont rev up as fast as EMD two cycles, but once there, they work great.
Type PTRA in your search engine, and look at the photos there.
Ugly, but useful.
Stay Frosty,
Ed

[Anonymous]

thanks buddy i'll do that
marty

[Mookie]

Wabash, that is where we difer somewhat. I work on a computer all day - and always want to know more about what is going on - but don't ever get to touch it except at the keyboard. BUT - you do at least know the a little about what you are running - the word here is that some engineers get on and don't know an SD70 from a Dash 9. Don't have to, so don't care. But even if you can't "fix" them, I bet your ears can tell you a lot about something when it goes wrong.

Jen

[foamer4000]

Jen,
I met a brakman on the UP. I asked wich power he liked better. He said the UP #7500 class becouse they had electric base board heaters. Most of the others had forced air heat in the cab. Other than that he had no opinion. These days I am suprised that some people can start and fuel their auto without assistance. Say hello to your driver and enjoy Nebraska railroading.
David

[wabash1]

You are right i Ko know the diferance between all my power and i most generally can tell when something goes wrong and can fix some of these problems. its the big stuff i cant do anything about. and i do know engineer who wouldnt know the differance between the 2 or care. just complain that its slow. i say well there is a reason but they dont want to here it all they care about is that if its got air conditioning.