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Western Railroad Discussion > Handling mid-train and end of train DPU?


Date: 08/11/19 16:32
Handling mid-train and end of train DPU?
Author: Lackawanna484

BNSF regularly runs very long trains through Flagstaff AZ with three or four units up front, three units mid-train, and four units on the rear.  I believe these are loaded westbound grain trains, with perhaps 150-180 cars.  They seem to go on forever, and are visibly slowing down by the time the pushers pass. One passed the camera about 5 pm local time last night.

Managing a train like this would seem like a challenging operation.  Do engineers routinely put up two fences, and control the mid and rear sets separately?  Or control them with the same set of commands?  Having the front of the train plus 80-100 cars over the top, while  seven units are still pushing up hill seems like a balancing act. Or having two sets in dynamic braking while the third is in run 8, etc

 



Date: 08/11/19 17:15
Re: Handling mid-train and end of train DPU?
Author: callum_out

Yes to the above, depends on the terrain and the requirements of the individual railroad.
With the usual limits on comm distance and the fact you can't put the remotes in dynamics
and the lead set in power, guess that's all still in effect, been like fifteen years since this
all started.

Out



Edited 1 time(s). Last edit at 08/11/19 17:19 by callum_out.



Date: 08/11/19 17:19
Re: Handling mid-train and end of train DPU?
Author: Android

With the advent of Trip Optimizer, I wonder how much actual input the enginieer has, often they can sit back and let the computer do it for them?



Edited 1 time(s). Last edit at 08/11/19 17:20 by Android.



Date: 08/11/19 17:42
Re: Handling mid-train and end of train DPU?
Author: Chico43

callum_out Wrote:
-------------------------------------------------------
> Yes to the above, depends on the terrain and the
> requirements of the individual railroad.
> With the usual limits on comm distance and the
> fact you can't put the remotes in dynamics
> and the lead set in power, guess that's all still
> in effect, been like fifteen years since this
> all started.
>
> Out

The last time I ran a DP train there was only one fence to put up. Where there is more than one DP consist, it's the engineer's call where he want to put it up if he wants to use it.



Date: 08/11/19 17:49
Re: Handling mid-train and end of train DPU?
Author: SD45X

The empties run fine all together. TO thinks it has to re engineer the wheel and usually tries toruns the rear DP out of fuel.



Date: 08/11/19 17:54
Re: Handling mid-train and end of train DPU?
Author: Chico43

Android Wrote:
-------------------------------------------------------
> With the advent of Trip Optimizer, I wonder how
> much actual input the enginieer has, often they
> can sit back and let the computer do it for them?

The Trip Optimizer doesn't run the train for the engineer. It is speed sensitive and It makes recommendations with respect to throttle, dynamic braking and air braking at a given location and the engineer makes all the adjustments. At least that's how it worked on the last one I used. The only thing I ever found it useful for was locating Form A's and Form B's  Other than that I usually told them that it wouldn't initialize and I ignored it.

I've been enlightened. I understand the TO can NOW handle the train. I'll bet there's never a dull moment!!.



Edited 1 time(s). Last edit at 08/11/19 18:42 by Chico43.



Date: 08/11/19 18:58
Re: Handling mid-train and end of train DPU?
Author: HogheadMike

On the UP in Pocatello, Idaho we run trains similar to this.  140 car loaded soda ash, 21,000 tons, 3 on the front, 4 in the middle and 2 on the rear usually.  We are not allowed to have more than two units, or 24 equivillent powered axles on the rear running per system special instructions (AC440 units are rated for 12)  We have an extremly difficult and technical territory to cover between Pocatello and Nampa, Idaho due to all of the undulations and sags.  I have tried to run these trains several different ways through the undulations and there are ways that absolutely DO NOT WORK.  The midpack of units will knock you out your chair every time it hits a downhill and your head end is still going uphill.  The way that I have found that works very nicely is to place the fence between the front units and the rest of the train.  I push on the mid set and the rear and use dynamics on the front to keep the slack bunched and the entire train running at the same speed.  When my head end hits an uphill, I come out to idle.  When it hits the flat again, I go to light dynamics, when they hit a downhill section I go a little deeper.  When they no longer hold due to the grade I set air, usually just long enough to retard the train through the sag.  When I enter the grade territory it's different and I use the fence the keep the head end bunched until the whole train is over the crest, then dropping the fence and running with all synchronized, since the entire train is on a downhill slope.

I've seen a few people on here mock my proffession by saying that trip sodomizer handles the train for us.  That system is garbage and I can, and do run a better train.  Half the trains don't even have it.  When I do have it and we reach a section where it wants to run I watch it like a hawk, and as soon as I find 3 mistakes I document them and cut it out, running it manually for the rest of the trip and turning it in on the EMS feedback screen.  Management has never said a thing to me for it.



Date: 08/11/19 19:09
Re: Handling mid-train and end of train DPU?
Author: Auburnrail

“Trip sodomizer” ..... Boy, spell check really gone awry
on that one!  Good post though, a lot to running a train
today. Really can respect that.
George Andrassy 



Date: 08/11/19 19:34
Re: Handling mid-train and end of train DPU?
Author: goneon66

great info hoghead mike.  thanks for posting it.........

66



Date: 08/11/19 20:52
Re: Handling mid-train and end of train DPU?
Author: callum_out

I'll have to dig out my training stuff from way back when but I don't think UP ever envisioned 21,000 ton 140 car
trains even with DPU. With better power and better dynamios though it's still left to the skill of the hoghead,

Out



Date: 08/12/19 03:33
Re: Handling mid-train and end of train DPU?
Author: fr8kar

The version that would tell you what to do (and was never happy with anything you did) was Trip Advisor. Eventually that gave way to Trip Optimizer then TO with air advisement then finally fully auto TO.

Posted from Android



Date: 08/12/19 05:13
Re: Handling mid-train and end of train DPU?
Author: Lackawanna484

Thanks for a great thread, And very helpful private messages.

Posted from Android



Date: 08/12/19 07:28
Re: Handling mid-train and end of train DPU?
Author: Hookdragkick

They are quite managable to run. Air is quick and when required to run the fence (Timetable), most engineers will fence off the rear consist--TO always fences off the rear too. I like my GE motors, but an SD70ACe's soft keys on the DP control screen are way faster, making rear transitions quicker, IMO. Seconds help on Heavy and Mountainous grades.



Date: 08/12/19 12:57
Re: Handling mid-train and end of train DPU?
Author: mapboy

Lackawanna484 Wrote:
-------------------------------------------------------
> BNSF regularly runs very long trains through
> Flagstaff AZ with three or four units up front,
> three units mid-train, and four units on the
> rear.  I believe these are loaded westbound grain
> trains, with perhaps 150-180 cars...

BNSF runs much shorter loaded grain trains, up to 118 cars loaded.  BNSF occasionally doubles up the empty grain trains, but it doesn’t seem to be widespread, just one or two here and there that I’ve seen.  UP has experimented with double LOADED grain trains to California and Oregon, and will try to make it routine.  One that pulled the train apart on Silver Zone Pass required a new crew and blocked the line for hours because of all the handbrakes that had to be applied, then removed, then another break in two.  If they work out how to avoid that, UP will double up the trains, at the same time killing a lot of crew starts.

mapboy



Date: 08/12/19 20:38
Re: Handling mid-train and end of train DPU?
Author: EOTMOVE

fr8kar Wrote:
-------------------------------------------------------
> The version that would tell you what to do (and
> was never happy with anything you did) was Trip
> Advisor. Eventually that gave way to Trip
> Optimizer then TO with air advisement then finally
> fully auto TO.
>
> Posted from Android

Fully auto TO doesn’t exist yet. Currently, the engineer is still in charge of the air brakes, even if TO advises him of air brake applications. Z2Z is coming soon...



Date: 08/12/19 20:42
Re: Handling mid-train and end of train DPU?
Author: EOTMOVE

HogheadMike Wrote:
-------------------------------------------------------
When I do have it and we reach a
> section where it wants to run I watch it like a
> hawk, and as soon as I find 3 mistakes I document
> them and cut it out, running it manually for the
> rest of the trip and turning it in on the EMS
> feedback screen.

What are some of the mistakes you’ve seen?



Date: 08/13/19 22:00
Re: Handling mid-train and end of train DPU?
Author: SSW41

That's not spell check. That's what we call it.

Auburnrail Wrote:
-------------------------------------------------------
> “Trip sodomizer” ..... Boy, spell check really
> gone awry
> on that one!  Good post though, a lot to running
> a train
> today. Really can respect that.
> George Andrassy 



Date: 08/19/19 07:50
Re: Handling mid-train and end of train DPU?
Author: Android

Chico43 Wrote:
-------------------------------------------------------
> Android Wrote:
> --------------------------------------------------
> -----
> > With the advent of Trip Optimizer, I wonder how
> > much actual input the enginieer has, often they
> > can sit back and let the computer do it for
> them?
>
> The Trip Optimizer doesn't run the train for the
> engineer. It is speed sensitive and It makes
> recommendations with respect to throttle, dynamic
> braking and air braking at a given location and
> the engineer makes all the adjustments. At least
> that's how it worked on the last one I used. The
> only thing I ever found it useful for was locating
> Form A's and Form B's  Other than that I usually
> told them that it wouldn't initialize and I
> ignored it.
>
> I've been enlightened. I understand the TO can NOW
> handle the train. I'll bet there's never a dull
> moment!!.

Yeah, I was kind of being tongue-in-cheek there, even if I've not heard stories, just knowing about the system would make me think it would have serious issues.

Myself, operating trains at the mine, I have nothing to do with Arse Optimizer and PTC,  I only have to deal with the slow speed computer, (which is all fine and dandy except on AC4400CWs... now with TO/PTC installed, it somehow screws up the slow speed controller on these units, all UP C44AC units are now so affected, and many BNSF AC4400 and C44-9Ws are as well.  This ruined what used to be my favorite slow speed control system, but it's such a niche application of the locomotive control systems I suspect it never will be fixed.)



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