Eastern Railroad Discussion > Question about PTC operating procedures on NS.

The subject of PTC vs. an up-coming move of N&W J #611, was recently brought up on the Steam & Excursion board. Someone, apparently knowledgeable in PTC policies/procedures on NS, stated that trains of less than 15 cars do NOT need PTC. Thus, I have a few questions:

1) If a train, freight or passenger, of less than 15 cars needs no PTC "protection", then what prevents such a short train from exceeding a speed restriction, exceeding the normal speed limit, or running into/through a form B at excessive speed?

2) If a train, freight or passenger, of less than 15 cars needs no PTC "protection", what prevents such a train from running into another train?

3) If a train, freight or passenger, of less than 15 cars needs no PTC protection, what prevents such a train from exceeding the speed past a yellow, or even failing to stop at a red signal?

I don't believe this applies to passenger trains/Amtrak on NS,only freight.



Edited 1 time(s). Last edit at 03/13/19 12:05 by WLE2679.

WLE2679 Wrote:
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> I don't believe this applies to passenger
> trains/Amtrak on NS.

Well, my questions still apply to a freight train. Also, since the N&W #611 move would NOT be under Amtrak, nor will it be a "passenger" train, then what?

HotWater Wrote:

> 1) If a train, freight or passenger, of less than
> 15 cars needs no PTC "protection", then what
> prevents such a short train from exceeding a speed
> restriction, exceeding the normal speed limit, or
> running into/through a form B at excessive speed?

...or without permission (Form B).

Technologically-speaking, nothing.  It makes the investment in PTC worthless in this context.
>
> 2) If a train, freight or passenger, of less than
> 15 cars needs no PTC "protection", what prevents
> such a train from running into another train?

This sounds like a Restricted Speed type of scenario, which PTC can't truly enforce anyway (other than a top speed).   So this question isn't too relevant.
>
> 3) If a train, freight or passenger, of less than
> 15 cars needs no PTC protection, what prevents
> such a train from exceeding the speed past a
> yellow, or even failing to stop at a red signal?

Again, technologically-speaking, nothing, and again makes the investment in PTC worthless in this context.

I'm with you that allowing certain trains, by rule, to operate without PTC on an otherwise PTC-required route seems very silly, and not all Class 1s have this exception.   Frankly, I'm surprised such an exception is allowed. 

I suppose what prevents a short train from exceding speed restrictions, etc. is what has been doing that for many years before PTC was even thought of. 

mp109 Wrote:
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> I suppose what prevents a short train from
> exceding speed restrictions, etc. is what has been
> doing that for many years before PTC was even
> thought of. 

So,,,,,you discount ANY human error ever happening?

Nothing in 49CFR §236.10xx, to the best of my knowledge, makes any distinctions based on length of train, either freight or passenger.  If this is something NS is doing, it can only be being done during testing.

Gordon 
 

I know the question was about the NS, but the UP recently changed the rules regarding the use of PTC on trains of 15 cars or less. Their upadated rule says that provided the controlling unit has had DBI (dynamic brake interlock) removed, PTC may be used on trains of any length. If the unit still has DBI, then the PTC can't be used on trains of 15 cars or less. I wonder if such a change is going to roll out on all railroads with PTC?

This topic has come up in local and regional meetings between NS management and BLET and SMART-TD union leaders.  The division road foreman of engines present stated the the 15 car and under movements would be under PTC eventually.  On my district many of these moves are done with non-PTC equipped engines with the dynamic brake interlocks still active.

gbmott Wrote:
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> Nothing in 49CFR §236.10xx, to the best of my knowledge, makes
> any distinctions based on length of train, either freight or passenger.

You are correct. This "length" thing sounds like they are accepting a certain amount of risk while phasing in PTC across the entire network. It isn't that a short train would not have the same issues as a long train, but until everything is upgraded there needs to be some management of where PTC engines are used and where yet to be upgraded engines can be used until all equipment is upgraded.

Interesting thread. Can someone elaborate on the implications of Dynamic Brake Interlock as it pertains to PTC?

Posted from iPhone

ble692-What is dynamic brake interlock?  

Thanks in advance!

Randy Lundgren
Elgin, TX

The dynamic brake interlock prevents a sevice train brake application from applying on the locomotives that are in dynamic braking.  I understand this can prevent the PTC computer algorithm from stopping the train in the predicted distance from the stop target.  In other words, the computer can't figure something out that the engineer routinely does.

Thank you!


Notch7 Wrote:
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> The dynamic brake interlock prevents a sevice
> train brake application from applying on the
> locomotives that are in dynamic braking.  I
> understand this can prevent the PTC computer
> algorithm from stopping the train in the predicted
> distance from the stop target.  In other words,
> the computer can't figure something out that the
> engineer routinely does.

Posted from iPhone