Western Railroad Discussion > Question for Engineers Running DPU

While using common sense is important, I am wondering if there are rules in place pertaining to throttle and dyn. brake use while running with the fence up. Watching Trip Opimizer run, I regularly see the dpu in a higher throttle position than the leader and I personally reduce the throttle on the lead consist to reduce wheel slip on grades and on slippery rail. Is there a maximum throttle difference in place anywhere? An example would be lead loco must be within 3 notches of dpu etc. My three inch thick rule book doesnt seem to cover this topic well...



Edited 1 time(s). Last edit at 12/01/18 10:27 by mttrainman1.

Depends on train make up and territory.
Just crawling in to bed after another 12 hour trip, if no one replies with a good answer I’ll try to Give you my take on it. Not that it means much lol
Posted from iPhone



Edited 1 time(s). Last edit at 12/01/18 05:03 by jointauthority.

I always ran with the "Fence" and kept the DPU's in run-8 most of the time... often head end in dynamic. But, I worked the Tehachapis and Beaumont Hill with SP for many years and understood how to operated with (or run) in-train helpers. I always enjoyed helper service. There is an art to being a good helper engineer. UPRR came along and wanted us not to use the fence. So, with their way of doing things, you had to think a little differently. I'm sure nowadays there are exact explicit rules on how they want the DPU's operated.
Retired SP/UP Engineer

Interesting disscussion topic.

However, I didn't know what a "fence" was.

I found this discussion to be informative...

http://cs.trains.com/trn/f/111/t/63618.aspx

And this...

https://www.youtube.com/watch?v=7B3_z96OKOE

Greg Stadter
Phoenix, AZ



Edited 1 time(s). Last edit at 12/01/18 07:40 by E25.

Trip Optimizer is the root of all evil, and like to break trains.

The last release of that tends to put the headend in N7 or 7.5 with the DP in 8 uphill.

It also likes to put the DP in DB going uphill out of holes. It did just that last trip so we fired it and ran manual the rest of the trip.

All it wants to do is use DB to keep the train slow enough where air is not needed.

I sent you a PM on your last question but didn’t get a response back.

In short, I leave the DP in power all the time. On flat areas or hills, I’ll leave them sync’d unless there are a bunch of cushioned drawbars back there, so I’ll have it adjusted for that.

We run a bunch of long trains so normally its midtrain DPs, but plenty of rear only if 8500ft or less.

I personally like rear only DP’s as its easier to control slack or use DB on it in the areas you can do it. Mid trains have whole ‘nuther train behind them to think about.

I learned the trade on RCE, which later morphed into DP. With RCE, we always had the remotes two notches above the leader, unless R-8 was needed on everything, and there were no fences. On the grain trains we used it on, the remotes were always 2/3 back in the train. We worried about the leader, the remotes, and what was between them, the rear of the train took care of itself. I retired 8 years ago today, and usually just turned the trip optimizer off.

Posted from Android

Some great replies, my poorly written 2 cents:

The only mention my rule book has about DP throttle setting is that when cresting grades the DP throttle must not exceed three notches above the lead consist. ABTH 105.10.1 C.

You don’t want to have the DP pushing too hard when coming over hills, not only will you obviously get a nasty run in but if you have a badly built train you can actually pop light cars out of your train with all the buff force.
Also got to be careful going into dynos hard when shoving hard with the DP, especially on curves.

I usually leave the DP 2 or three notches above the head end running on undulating territory, but if I’m on a hard pull I’ll go to notch 8 on the head end if I really need the power, but I try to avoid it just to be safe.
Obviously you also have to take into consideration how much power you have on the head end vs the rear end when running.

I’m horrible at explaining train handling but hope you could understand my rambling lol
It’s not much but it works for me



Edited 1 time(s). Last edit at 12/01/18 15:14 by jointauthority.

ABTH 
Starting, then accelerating: limit remotes to 1-2 notches above head end 
Cresting: reduce remotes to no greater than 3 notches above head end or if in dynamics on head end.
Slowing, controlling slack/speed and stopping: limit remotes to 1-2 notches above head end until head end in idle or dynamics.
 



Edited 1 time(s). Last edit at 12/01/18 16:20 by Hookdragkick.

Doh missed that part lmao

Hookdragkick Wrote:
-------------------------------------------------------
> Starting, then accelerating, limit remotes to 1-2
> notches above head end 
> Cresting: reduce remotes to no greater than 3
> notches above head end or if in dynamics on head
> end.

Posted from iPhone

@joint, I missed your post completely or might of omitted the cresting. Oops!