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Control of Multiple Locomotives

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Control of Multiple Locomotives
Posted by JPS1 on Thursday, June 10, 2021 7:08 PM
I watched a 120-car train pass by my favorite train watching spot today.  It had three GE ES44AC locomotives on the front and an SDM70AC on the back.
 
Who would have coupled the locomotive to the back of the train?  And who would have activated the controls on all four locomotives so that the engineer had control of them?
 
What test procedures does the engineer run through to make sure that he/she has control of all four locomotives? 
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Posted by BaltACD on Thursday, June 10, 2021 7:35 PM

JPS1
I watched a 120-car train pass by my favorite train watching spot today.  It had three GE ES44AC locomotives on the front and an SDM70AC on the back. 
Who would have coupled the locomotive to the back of the train?  And who would have activated the controls on all four locomotives so that the engineer had control of them?
 
What test procedures does the engineer run through to make sure that he/she has control of all four locomotives? 

As the saying goes - It Depends!

The originating crew MAY have gotten all four engines from the engine facility and attached one to the rear of the train and configured it for DPU operation and performed the necessary tests while in the near vicinity of the engine; then proceeded to the head end of the train and go through whatever work was necessary to make the train complete.  Once the train was complete they would perform the prescribed air test (the train or its individual tracks may have had a Class 1 air test done by the Car Department who would have left a 'Air Slip' with the details in the lead knuckle of the train or each track tested).  If the train or all the tracks of it have Air Slips then the crew can perform a Class 3 air test on the completed train.

The DPU may be placed on the rear of the train or other desired location by a 'Hostler' or some other authorized party.   Jeff Hergert would be the authority in how this occurence would  be set up and tested to insure proper operation of all the controlled locomotives.

Of course crews taking charge of the train a Crew Change locations will assume that all the locomotives in the train have been correctly configured.

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Posted by jeffhergert on Friday, June 11, 2021 5:30 PM

Who initially sets up the power configuration depends on where your at.  Larger yards that have a diesel facility (that includes machinists and electricians) will usually set up the power consist.  That is, MUing engines, doing the daily inspectinons, proper engine consist air tests, testing cab signal and PTC equipment.  They may initially set up the DP consist.

If the yard has hostlers, they will move the power to the proper departure tracks.  They may place the DP in the proper spot.  They may also set up the DP if not already done.  They may leave the consist on a convienent track and let the road crew place the DP.  At originating yards, the DP may be placed by "doubling" or "tripiling' over to the DP.  That is, leave the DP where it is and have the lead engine pick up a track, move it over to the next track, etc.  A mid train would usually be placed at the head of the track relative to the position it will be when the train is together in one piece.

If there is no diesel facility, and/or no hostlers, the road engineer does it all.  If engines, including DP consists, are changed by picking up or setting out, or conventional trains are reconfigured to DP train at intermediate points, the road engineer does the work.  Including any engine consist test that are required.   

Jeff  

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Posted by ORNHOO on Friday, June 11, 2021 6:07 PM

BaltACD
Of course crews taking charge of the train a Crew Change locations will assume that all the locomotives in the train have been correctly configured.

You know what they say about that word "assume" : https://www.kuow.org/stories/sabotage-caused-washington-state-oil-train-disaster-rail-union-says

 

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Posted by BaltACD on Friday, June 11, 2021 7:54 PM

ORNHOO
 
BaltACD
Of course crews taking charge of the train a Crew Change locations will assume that all the locomotives in the train have been correctly configured. 

You know what they say about that word "assume" : https://www.kuow.org/stories/sabotage-caused-washington-state-oil-train-disaster-rail-union-says

One reason why trains should be stopped with the slack stretched.  With all coupling stretched pins can't be pulled to permit cars to uncouple.

When the Relief Crew got on the train they should have been able to detect that the trainline was not reponding properly to brake pipe manipulations account the anglecocks having been closed.  DPU's and/or EOT's display brake pipe pressure which SHOULD be realatively the same as the pressure being displayed on the head end and should mimick a brake application initiated from the head end.

 

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Posted by SD70Dude on Friday, June 11, 2021 8:30 PM

If you have a DP unit it takes a bit of careful handling to bring a train to stop completely stretched.  You would have to independent motor the remote (put the fence up), reduce it to idle, and then set a brake and pull the train to a stop with just the lead consist. 

If you are leaving the train unattended you would then have to perform a handbrake test in most cases, which will most likely result in the slack adjusting and bunching up somewhere in the train, unless you have stopped with 100% of the train on an ascending grade. 

A continuity test is a normal part of a crew change, though in Canada we no longer have to perform one at direct tradeoffs as long as the controlling locomotive has operative DB and everything else appears normal (the rationale behind this is to save air when it's cold). 

If you are taking over a DP train that has been left unattended, or at a direct tradeoff where the inbound has set the automatic brake, you do what is called a "train check" to ensure the train is still in one piece.  This procedure cuts out the remote's brake valve, and then you release the brake on the lead unit.  When the remote senses the rise in brake pipe pressure it will cut its brake valve in again and start pumping air. 

In Canada a train designated as Key or ERAP must receive a pull by inspection at each crew change, I presume the U.S. has a similar rule.  But this might not have caught the vandalism in this case, the two sections of the train might not have separated right away if the remote was pushing hard enough, and it would be easy to miss a closed angle cock as it goes by, it is normal practice to look some distance in the direction the train is coming from to try and spot signs of dragging equipment or sticking brakes before they reach you, as opposed to looking directly at the car closest to you. 

There have been other cases where a DP train has separated and the trailing portion has followed it for some distance, or run away by itself.  We had a single unit get up to 85 mph in Saskatchewan last year, though that incident was the crew's fault, not vandalism.  

There have also been cases where one half of the train goes into emergency and the other does not, due to various kinds of trainline blockages.  Pinched air hoses, ice buildup, and closed angle cocks all come to mind. 

It is very possible for an angle cock to close by itself, probably the most famous example is the runaway passenger train that ended with a GG1 in the basement of Washington Union Station.   I actually had this happen to me on an empty hopper train, the auxiliary air hose (to power the hopper doors) on one car reached over and bumped the brake pipe angle cock on the next car until it was completely closed. 

While I suppose it is not impossible, I would consider it incredibly unlikely for both angle cocks to become closed and the pin to lift at the same location without a human being involved.

Greetings from Alberta

-an Articulate Malcontent

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Posted by jeffhergert on Friday, June 11, 2021 9:45 PM

Our rules require a train check to be done everytime a train stops and does not immediately start moving again.  Called "delayed departure."  During extreme cold weather the rule will be suspended at other than crew change points.  This is to reduce the possibility of problems should the DP's brake equipment freeze up.

Still if you knew what you were doing and were willing to take a risk, someone could split the train after the train check was done.  Once split, the DP's brake pipe pressure wouldn't be much different since it's reflecting the bp pressure where the DP is pumping air into the pipe.

I can see the rear end possibly picking up speed if it's portion is lighter.  However, the DP would still respond to throttle/dynamic/air brake commands from the lead engine.

Jeff

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Posted by jeffhergert on Friday, June 11, 2021 10:00 PM

Just found this update.  The original linked article was written with a sensationalist flair.  The speed, not mentioned in the original linked article made it sound like very high speeds were reached.

Another thing in my linked article involves the NTSB.  So far, it's investigation doesn't show the incident to be intentional.  

I must admit that over the years I've lost respect for the NTSB.  They've usually been good at finding out what happened, but some of their recommendations at times have been unrealistic.  To think that this wasn't intentional takes the cake.

Report: Oil train split in two before derailing near Custer | Bellingham Herald

Jeff

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Posted by SD70Dude on Friday, June 11, 2021 10:29 PM

Something I forgot to mention, the day after this wreck we got a bulletin about a new DP software update:  Speed comparison. 

It will give an alarm if the measured speed difference between the lead and remote consists reaches 5 mph, and a difference of 10 mph will trigger a penalty brake application. 

Greetings from Alberta

-an Articulate Malcontent

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Posted by BaltACD on Friday, June 11, 2021 11:08 PM

jeffhergert
Just found this update.  The original linked article was written with a sensationalist flair.  The speed, not mentioned in the original linked article made it sound like very high speeds were reached.

Another thing in my linked article involves the NTSB.  So far, it's investigation doesn't show the incident to be intentional.  

I must admit that over the years I've lost respect for the NTSB.  They've usually been good at finding out what happened, but some of their recommendations at times have been unrealistic.  To think that this wasn't intentional takes the cake.

Report: Oil train split in two before derailing near Custer | Bellingham Herald

Jeff

In the 21st Century I have seen the NTSB bend with the political winds in some of their 'findings'.  I likewise have lost many elements of respect for the NTSB.

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