I have not encountered that, but it is possible to do if you short circuit the right combination of wires together.

PC

OK, since we're talking pin/wire numbers- Dropping engine run (16) should have brought the beast back to idle. Also, 'D' (wire three) by itself (without A, B, and C, or 15, 12 and 7) should have shut down the engine. Alcos have a pushbutton on the control stand labled MU shutdown, and I believe that on the older EMDs pushing the throttle forward ahead of idle does the same thing. Sorry, but I work with OLD stuff-

Centering the reverse switch, as well as closing the throttle should have dropped out 8 or 9 (FO, RE) and 6 (GF), as PCook mentioned. I wonder how control (13) was wired. Did it come from the diesel and go through a toggle switch before going to the engine run, throttle and reverse switches? If so, dropping control should have made all of those circuits go dead.

Again, I'm NOT second-guessing the crew or UP's electricians, but I have done a bit of wiring and troubleshooting (Alcos, little GEs, EMDs and RDCs), as well as studied many wiring diagrams, and am trying to point out some things that apparently didn't work. I'm curious as to what happened, and will apply 'lessons learned' to some of the older equipment I've worked on, if neccessary.

Going back to the videos, a couple of questions:

Judging by the brake shoe smoke it looks as if an emergency application had been initiated. But notice in the videos that the MU air hoses are all connected and the brake application has not been bailed off the diesel, but at the same time it looks like the driver brakes on 844 are not applied. So is the practice to run 844 with the mountain cock set to cut out the driver brakes?

And if the driver brakes are cut out how do you slide the wheels to get flat spots, or has someone else on this forum already offered the correct answer in a previous post?

PC

Couldn't the locomotive brakes simply have been bailed off, as opposed to being cut out?

Sure but I think Preston is saying he thinks that the diesel brakes were applied and with full MU hoses, if you bailed off they would all be bailed off.

Hey Preston, do you actually think you see the brakes unapplied on 844 or just not seeing brake shoe smoke? Because if the latter, if the wheels are locked there may not be any smoke.

Steve

On trainorders, someone posted a corner of the schematic used for the MU box on the 4449 for the freedom train (dated from the 70's), that corner had notes that the engine shutdown switch and the fuel pump switch MUST be on in one of the diesels being operated from the MU box, leading one to believe that the box had limited functions compared to a standard MU trainset. It was suggested that most of the steam MU boxes were duplicates of this unit from the schematic that has been passed along ever since.

On the 1982, are all of the functions computerized? in other words, do all available MU wires simply feed the computer? I'm usually not fond of computer failure but if the shutdown, field, fuel, throttle, etc all go though the computer, a glitch or bug there could be the thing that ruins your whole day, at least leaving no other way to shut it down or unload it through the MU. My source who has direct connections to the steam crew, said that the only way they got the 1982 to unload was once they slowed a crewman jumped off the 844 and either jumped on the 1982 or was able to hit the cutoff switch on the side..

Robert

I have two questions:

1) If an emergency application would have taken the diesel off line, why would the engineer not have made an emergency application rather than trying to stop the diesel with the steamer’s independent brakes.


2) If the engineer had made an emergency application and the diesel stayed in full power, would it have pulled the train in two close to the diesel, and simply kept pushing ahead harder than before because it was relieved of the train resistance behind it?

Answering Steve's question, the drivers are turning in the video but it did not appear that the driver brakes were applied, while the brakes on the diesel are very obviously applied. As Steve noted earlier, with the air MU connections if the 844 is bailed off the diesel should be as well.

PC

Is there any video of the train actually coming to a stop? Because if all video shows the drivers turning when did they slide? Could there have been an emergency application that was bailed off too late, causing a momentary slide at speed?

@Ron:
1) Independent alone? No one has suggested that.
2) Not sure what you mean.

Steve

Partially answering Robert's question (as I do not have a schematic of the 1982 with me), on all the computer controlled locomotives I have seen, when the locomotive is trailing in MU, its generator field contactor is energized from the external feed on trainline pin 6 coming back from the head end. The computer usually has the ability to cut this feed off and unload the unit, but it is not able to bypass the pin 6 feed and pick up the generator field contactor on its own when trailing. It is arranged this way so that when you shut off the generator field switch on the lead unit, the entire consist drops out of power. Same is true when you throttle back to idle, that cuts off pin 6 feed and drops power on all units in MU.

PC

Let me clarify question #1 of my two previous questions:

Many have said that if the engineer had put the brakes into emergency; dumped the air and dynamited the brakes on the whole train; then that action would have taken the helper out of power mode, thus ending the runaway. As Mr. Cook mentioned, the controls would have let the helper stay under power for something like 20 seconds before shutting down, but after that, the diesel would shut down power.

If the engineer had done this, it would have applied the brakes to all the wheels of the train including the locomotives. So it would have possibly slid the drivers on #844. However, if the engineer bailed the independent bakes off of the steamer, there would have been no risk of sliding the wheels.

So that course of action would have taken the diesel out of power mode, stopped the train, and not damaged the drivers of #844.

Is there any reason why this could not have been done?

Ron, I suggest watching this video, the low angle shot (second camera sequence) around 1:24.

http://www.youtube.com/watch?v=j9ukJHWUuhQ

Looks to me like they made an emergency application, note the brake shoe smoke and the sand haze, but the diesel is not bailed off, which would indicate the 844 is not bailed off either, since they are MU connected. However stop the action as the drivers go by and look at the brake shoes on the drivers, I don't see any evidence of contact. Also play the tape and listen to the audio of the low angle shot, I don't hear any brake shoe hiss as the drivers are going past.

As far as the wisdom of making an emergency application is concerned, we don't know all the circumstances of the situation so who can really say other than the engineer. But in any case, turning off the generator field switch should have dropped the diesel out of power.

PC

Yes I have looked at that video. If you turn the sound up, you can hear the diesel in high throttle. There is also a slow motion version that somebody posted. The slow motion video only shows a close-up of the trailing truck on the second auxiliary tender and both trucks of the diesel. You can see the pistons extended on all three of those trucks. I agree that it does not seem like the brakes are set on the drivers of #8444. I do not know what to conclude from all of that.

I assume that an emergency brake application has not been made on the whole train with the automatic brake, and therefore, the brakes that show to be set on the last tender and on the helper are not part of an emergency application of the automatic brake. The reason I don’t think that the air has been dumped on the whole train is that the train is not slowing down.

However, with only six cars behind the diesel, maybe it is possible for the diesel under full power to simply keep the train moving even with all brakes set in full emergency application. If the diesel can keep the train from slowing down, the brake may just stay in a permanent fade, not being able to produce enough friction at that speed. And with such a short train with brakes fully applied, but unable to produce much friction, it may have not been able to produce enough resistance for the diesel to pull a drawbar.

So if all of that was happening, it would mean that the engineer had dumped the air, and was somehow able to keep the brakes released on #844; and the automatic shut down of the diesel did not occur for some reason. However, I would expect to see more smoke from the six cars behind the diesel if those cars all had their brakes fully set.

A few points:

1) The MU control is modernized beyond the 70's design. I believe the box has a generator field switch as does the box run on 1522.

2) How did it happen? Independent brakes were not bailed off(.)

3) If you pause the video at the right point(the beginning of the 1:24 mark) and play with rapidly pausing and playing you can see that the pistons are extended on the trailing truck. Considering atleast one axle has tires it is reasonable to think that if the engine does have a mountain cock it would cut out the trailer as well as the drivers.

http://www.youtube.com/watch?v=j9ukJHWU ... re=related

John

I know the M.U. control box at the GCR has a Gen Field switch.

Cheers, Jason