Western Railroad Discussion > Dynamic Brake Failure at Kamela

Back in the spring, I saw something trackside that I'd never seen before. I have a few questions about what happened and would be curious to get TO's take.

Here's the situation. A Hinkle-North Platte manifest with some rather crusty power comes to the summit of the Blue Mountains at Kamela, OR, and slows to a stop for a few minutes at the end of the double-track, with its train draped over both sides of the hill. (For those who don't know, immediately on either side of this summit there is a long and steep descent, I believe 2.2% in each direction, not totally sure.) After MOW clears up, the train starts down the hill -- noticeably more quickly than is typical over this crest. As soon as it has passed my location, the train abruptly grinds to a stop. 

The crew radios the dispatcher. "This fine outstanding power that Hinkle gave us doesn't have dynamics," the engineer says. He adds that he felt the train getting away and made a full air brake application just before PTC kicked in and did it for him, and that "we're now a giant paperweight on the hill. We're not going anywhere." The dispatcher promises to send a supervisor up from La Grande right away to help sort it out.

It would have been interesting to stick around and see what happened, but we had to get home...

So here are my questions:

1) If a train loses its dynamic brakes like this, what is likely to be the cause? I can't imagine that a number of locomotives simultaneously are being used with bad dynamics / all failed at the same time [the Espee San Bernadino incident comes to mind, but... you'd like to think that wouldn't happen now], so I'd imagine that perhaps there was some failure in the lead unit that impaired its ability to use the braking power of the other units, but I'm not sure that's correct, or what sort of failure that would have been.

2) How close is this to being a runaway? Is there a speed at which a heavy train (not sure of the tonnage, but this train was in the vicinity of 80 cars in length and rather loaded -- not as long as some of the HKNPs you see here, but not nothing) coming down a 2+% grade can't be corralled by air brakes anymore? How fast would the train have to be going?

3) What would be a typical / ideal way to resolve a situation like this? Once the train is a "giant paperweight on the hill," how do you get it OFF the hill?

Just a few questions I've been pondering for the last few months. Thanks.

And kudos to the crew for being alert and calm.

 

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Could be the "Dynamic Brake Control Circuit Breaker" on the control stand tripped / not flipped up - that would cause all dynamics in the consist to not work.

Could have simply been the dynamics on the units being cut-out. I actually had a guy give me a train complaining the "dynamics are really weak". I walked through the units and both trailing units had the DB cut-out.

In the old days simply put a set in it and pull it down the hill. Seems strange the guy went from Hinkle all that way and never tried the dynamics but stranger things have happened.
 



Edited 1 time(s). Last edit at 08/14/18 09:41 by Railbaron.

It probably wasn't that every unit had B/O dynamic brakes, just enough of them to make it hazardous. Sounds like at least one of the DPU units was working in Dynamic. GE locos tend to be fail safe, in so much that any little glitch will cause them to jump out of whatever mode they are. Saves the locomotive from self inflicted damage, but sure can be a nasty surprise to the engineer. I regularly handle 60~70 car loaded trains down 1.2% grades just using the air brakes. I do this on purpose to keep my air brake skills up to speed as you don't want to become too reliant on the dynamic brake. But I'm certain I wouldn't want to try it on a 2.2% grade. I can't blame the engineer for wanting some extra braking power, but a little surprise the lack of dynamic brakes didn't become apparent leaving Hinkle and heading down the grade into Stanfield.

Ted Curphey
Ontario, OR

I believe the engineer told the dispatcher something to the effect that he had noticed leaving Hinkle that the dynamics seemed odd and weak, but that they had kicked in after a minute or two and then been OK...

(Coincidentally, this train had just met a soda ash load at Meacham which had also reported issues with the dynamics on at least one unit (another older AC4400CW, this one ex-SP) and which had sat in La Grande for a while before the powers that be decided that they still had more than enough braking power for the hill and that they should just "keep an eye on it.")

 

You want to see dynamic brake failure, click on this like to see what I filmed in Cozad, Nebraska in 1991. Our first UP train of the day was a local. Just after they blew the lousy sounding horn for a grade crossing, the dynamic brake grid explodes with part going into the air. My first comment was that I thought it blew its turbo, but as it goes by I could see electrical arcing and melting metal flow.


https://www.youtube.com/watch?v=mCk21G2LR-M

So don't these new train puller thingies come equipped with a feed valve?  Is'nt that how ot was done in the era of steam?

mns019 Wrote:
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> So don't these new train puller thingies come
> equipped with a feed valve?

No, not with computer controlled electronic air brake.

Is'nt that how ot
> was done in the era of steam?

Nope. They probably would have set retainers on the cars.

I would have just pulled it down the hill. That happens once in a while anyway when I screw up and set a little too much air for air and dynamics lol.

GN599 Wrote:
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> I would have just pulled it down the hill. That happens once in a while anyway when I screw up and
> set a little too much air for air and dynamics.  lol.

Amen to that. And the steep part of that grade is only about 6 miles or so and then it flattens out quite a bit.

I have been at that same spot several times and could tell on your video that the speed was increasing too fast. It made me feel very uncomfortable just watching the speed increase! Cudos to the crew that day!

Lol I rode with a fellow engineer buddy once while working set back as a conductor, light power he tried to go into dynos and was getting nothing. Started pitching a fit about band order dynos, I walked across the cab and cut the DBs back in on the back wall (dash 9) and told him to try em again. Lol I always check my consist even if the cards are signed. Too many idiots out there.

Yes in the rule book it allows for pulling trains down hills with the air set.
On GEs you can always open the back cabinets and flip the toggle switch to get into level 2 and check any codes or alarms.

Posted from iPhone



Edited 1 time(s). Last edit at 08/14/18 20:15 by jointauthority.

Certainly a scary situation but some of those UP units looked pretty bad as far as maintenance is concerned. That alone would make you wonder about the mechanical condition of some of those locomotives.

Jim
Hatboro, PA

Theirs nothing in the GCOR about using retarders....

You make a 20lb set. The conductor walks the train and

turns the retarder valve from out to set. Then drag the train down hill.

It was done before dynamics......

AMK SDP40f
Spring,

Because that would be in the ABTH

SDP40F Wrote:
-------------------------------------------------------
> Theirs nothing in the GCOR about using
> retarders....
>
> You make a 20lb set. The conductor walks the train
> and
>
> turns the retarder valve from out to set. Then
> drag the train down hill.
>
> It was done before dynamics......

Posted from iPhone

SDP40F Wrote:
-------------------------------------------------------
> Theirs nothing in the GCOR about using
> retarders....
>
> You make a 20lb set. The conductor walks the train
> and
>
> turns the retarder valve from out to set. Then
> drag the train down hill.
>
> It was done before dynamics......

I believe the auto spell check may have gotten you, as railroad rolling stock does NOT have "retarders".  They were/are retainers.

SDP40F Wrote:
-------------------------------------------------------
> Theirs nothing in the GCOR about using retarders....

Rule 34.5.5, at least in UP's Air Brake rules.

On Dash 2 EMDs If the DB blower is worn and slow to come up to speed, AND at some point you ramp up dynamic braking amps too quickly, the dynamics will trip out, and you will get no alarm. Whenever I get a consist with such engines I always check the annunciator...to make the sure the DB's aren't tripped....reset them if they are, and make a mental note to plan dynamic braking so as not to ramp up the current too quickly.