Eastern Railroad Discussion > PTC and dark territory

How does PTC work in dark territory?  Is it tied into track authority system or something else?

John

it knows your authorized limits, switchs all report there position
 

PTC works off of GPS and input from signals and computers. They programmed the gps coordinates for each point on the railroad. When a dispatcher gives you main track or other authority with defined limits, PTC knows the exact location of the points given. It then enforces the speeds and limits. 

Joe


DocJohn Wrote:
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> How does PTC work in dark territory?  Is it tied
> into track authority system or something else?
>
> John

Here is a video of how the Alaska Railroad does it. https://www.youtube.com/watch?v=7MHfCTGTLFM

Thank you very much for your replies.  Video provides very good explanation.  John

But by definition, there are no signals in dark territory?

Victor A. Baird
http://www.erstwhilepublications.com



Edited 1 time(s). Last edit at 11/05/19 17:53 by wabash2800.

Signals are not required for PTC.

wabash2800 Wrote:
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> But by definition, there are no signals in dark
> territory?
>
> Victor A. Baird
> http://www.erstwhilepublications.com


Hence the term dark.

How does PTC know what track you’re on in dark territory?

Joey posted: "PTC works off of GPS and input from signals and computers". I also know what dark territory means.

And if signals are not required for PTC, why did railroads invest in new signals?

Victor A. Baird
http://www.erstwhilepublications.com


justalurker66 Wrote:
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> Signals are not required for PTC.



Edited 1 time(s). Last edit at 11/07/19 16:16 by wabash2800.

wabash2800 Wrote:
-------------------------------------------------------
> Joey posted: "PTC works off of GPS and input from
> signals and computers". I also know what dark
> territory means.
>
> And if signals are not required for PTC, why did
> railroads invest in new signals?
>
> Victor A. Baird
> http://www.erstwhilepublications.com
>
>
> justalurker66 Wrote:
> --------------------------------------------------
> -----
> > Signals are not required for PTC.
BEcause the old relay logic was long in the tooth and unrepairable, but also not compatible with the new gadgets that satellite delivered PTC is. 

If signals are present, their current state needs to be reported to the PTC system. Older signals that were not compatible with PTC needed upgrades. Signals not present did not need upgrades.

Think of PTC as an automated conductor. The conductor is responsible for the safe operation of the train and operates based on the authority given to the train by the dispatcher. If you understand how trains are operated without signals then you should be able to understand how PTC operates without signals.

justalurker66 Wrote:
-------------------------------------------------------
> If signals are present, their current state needs
> to be reported to the PTC system. Older signals
> that were not compatible with PTC needed upgrades.
> Signals not present did not need upgrades.
>
> Think of PTC as an automated conductor. The
> conductor is responsible for the safe operation of
> the train and operates based on the authority
> given to the train by the dispatcher. If you
> understand how trains are operated without signals
> then you should be able to understand how PTC
> operates without signals.

Unfortunately that's how the carrier's feel but you'll get smacked a good one if you pull that on a rail. PTC is not a panacea...it does fail, and does so more often than the worst Conductor....in fact most failures are handled with grace by a competent crew....sometimes bad things happen that no one can help, and no magical billions will prevent. 

The intent was to illustrate why signals do not need to be present for PTC ... conductors do not need signals, neither does PTC.
The intent was not to say that conductors no longer need to be present when PTC is present.

Unfortunately a few bad rails have led to PTC. My long standing opinion is that if rails don't want PTC they should stop wrecking trains. The few are making the rest look bad.