Western Railroad Discussion > Train Service Folks: is this a good way to build a consist?

All,

On October 17, 2018, I shot a UP MRONY descending the Front Range at Plainview siding. The Moffat has a ruling grade of somewhere around two percent. There were three C-C units on the
head end and a single DPU. As the train passed I noted that all units were on line and in dynamic braking. There were 326 axles counted in the train by a defect detector, thus a good-sized train. Clearly the train
had crested the other side of the Rockies and had climbed it's nastiest grade, between Tabernash and the west portal of the Moffat Tunnel, known as Winter Park Hill without issues.

The question is this, from the image I snapped of the rear of the train, is the presence of the two empty flats right ahead of the DPU an acceptable way to build a train, or is it
just asking for a "stringlining" incident or "popping" the lightweight empty flats off the rails when the DPU is under heavy load?

Thanks for any reply......

Rich Farewell

 

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Perfectly fine - if there was a restricted car back there, 99.99999% of the time computer will catch it.

And what’s a C-C unit?

Do you want the real answer or UP's answer.

According to UP, that is legal. (I do believe traction motors would need to be cut out if I remember correctly - can't exceed 10 "powered" axles).

If I were building the train, I sure wouldn't want that.
 



Edited 1 time(s). Last edit at 12/04/18 17:20 by Railbaron.

No that's perfect, it allows the engineer who's not in the remote to see ahead! Put a two or three way FRED on the back of the
train, move the remote up ahead of those flats and things would be fine. Now let the UP jump in and tell you that I've wasted
two hours and $10,000 to solve a problem that doesn't exist.

Out

MP683 Wrote:
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> And what’s a C-C unit?

3 axle truck-3 axle truck.

No one calls engines by CC, etc.

The proper answer for above is it depends on the train make up and weight.

It doesn’t “look” right, but they can very we weigh (and they can) just as much as the cars ahead.

On heavy grade there are no restrictions for that type of engine to be placed there.

On DP’s you do not cut out axles.

But most UP AC engines have a feature called controlled reactive effort that limits the power until your around 12mph (forget the actual number).



Edited 1 time(s). Last edit at 12/04/18 17:40 by MP683.

Does an engineer have the option to refuse a train if they don't like the way it was built?

Or if the train has a low horsepower to ton ratio, or a barely minimum number of working brakes?

Posted from Android

Empty flat cars are heavy. Sometimes they will out weight box cars.

Posted from Android



Edited 1 time(s). Last edit at 12/04/18 17:55 by LocoPilot750.

On the UP trains may be built up to the TPA limits for the territory.

The train makeup may be poor, but if it doesn’t violate the rules, there isn’t much you can do about it.

MP683 Wrote:
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> ...
> On DP’s you do not cut out axles.

I beg to differ, unless there has been a change in rules since I retired, you certainly can cut out TM's on DP units to get your powered axles low enough to comply with restrictions. The only difference is that you'd link in "FTE" mode instead. While not overly common, we used to do it on our grade somewhat often if we had a bad rear-end. 

> But most UP AC engines have a feature called controlled reactive effort that limits the power
> until your around 12mph (forget the actual number).

It's not based on speed but tractive effort - limits tractive effort to 10,000 pounds per equivalent powered axle (120,000 pounds total tractive effort). I do admit you will only see these loadings at low speeds but the "CTE" is not actually based on speed.

In the case above, without looking it up (and I do not plan to because I don't care), I believe those cars would be light enough to be retricted to 10 powered axles shoving on them. 

Update: I lied, I did look it up and because those would be "conventional" cars, that helper is legal with all 12 axles working.



Edited 3 time(s). Last edit at 12/04/18 18:12 by Railbaron.

Why would there be a 'minimum number of working brakes' allowed out on the road, knowingly ??  If the engineer knows it, why would he leave the  terminal in that condition?

CTE mode is 110,000lbs of effort. Been that way for some time now. After you get to about 10-12mph full effort will develop, which is still under 110,000lbs.

The feature limits starting continuous effort so your not squiring something out.

On Heavy grade territories, you can have upto 20? Powered axles on the rear.

A C44 is only 12.

Edit: on heavy grades, there is no restriction for 10 or less powered axles

If a full motor like this, nothing lighter than 45 tons ahead of it.

Those cars are usually around 50ish tons



Edited 2 time(s). Last edit at 12/04/18 18:10 by MP683.

There was nothing said about brakes.

It leaves its Class 1 terminal 100% working brakes.

A certain number of brakes are allowed to be cut out if defective enroute, and must be setout or repairs at its next 1000mi inspection.

MP683 Wrote:
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> ...
> On Heavy grade territories, you can have upto 20? Powered axles on the rear.

It used to be 23 powered axles, which is where the CTE came in, but it looks like you're now allowed 24 axles provided there are no restricted cars.


 



Edited 1 time(s). Last edit at 12/04/18 18:16 by Railbaron.

The have done a bunch of updating with TPA and EPA down to each segement and what they want to move. I think the Mojave sub wants the world on it - but the same train elsewhere will have you shutting everything down

CTE limits it to 11.0 powered axles, but I think it’s only on the controlling unit.

So two ACs I’m the consist would give you 23.1 axles which is rounded down to 23.0.

I can’t remember the last time I’ve seen a train in CTE mode.

Posted from iPhone



Edited 1 time(s). Last edit at 12/04/18 19:04 by MP683.

I am confused about  "powered axels".  The DPU on this train is one engine.  It has 12 WHEELS which have 6 AXELS.  So why is it referred to as "12 powered axels"?

It helps us RR's to compare standard units, SD 40-2's  6 axles=6 axles with AC units.  AC4400CW  6 axles =12 axles or two SD 40-2's.

Eng.Shadetree

It takes care of mixed consists where you might have a D87 motored unit mixed in with a unit with GEB13 motors
where the AC motor would roughly rate twice what the DC motor would. In the early days of the AC units the roads
would try not to mix the units because of the differences in short time continuous rating vs how long do you want
to grind along. Thankfully it's not so much as issue anymore (hopefully).

Out

MP683 Wrote:
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> CTE limits it to 11.0 powered axles, but I think
> it’s only on the controlling unit.
>
> So two ACs I’m the consist would give you 23.1
> axles which is rounded down to 23.0.
>
> I can’t remember the last time I’ve seen a
> train in CTE mode.
>
> Posted from iPhone

You are correct, I misspoke earlier. It limits the unit you are linked to only to 11 axles and limits loading to 110,000 (10,000 pounds per axle). So with twi C44ACCTE's in CTE mode you'd have 23 axles (11 + 12.1 for the second C44ACCTE). I see now it appears 24 axles are allowed so I guess everything is FTE unless there are restricted cars.



 

tomstp Wrote:
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> I am confused about  "powered axels".  The DPU
> on this train is one engine.  It has 12 WHEELS
> which have 6 AXELS.  So why is it referred to as
> "12 powered axels"?

Because with the advanced wheel slip systems and computer control the actual tractive effort is the equivalent of 12 axles compared to say an SD40 (just an example).

The special instructions list locomotive classes and the equivalent powered axles and dynamic brake axles.



Edited 2 time(s). Last edit at 12/04/18 20:18 by Railbaron.