Eastern Railroad Discussion > CSX files to drop ATC on ex-RF&P

KV1guy mentioned this in another thread, but I thought it deserves a thread of its own so that the details are clear. 

"CSXT requests permission to discontinue the use of the automatic train control (ATC) segment of the cab signal systems (CSS) onboard equipped CSXT locomotives that operate on the RF&P subdivision, located between Richmond, Virginia, and Washington, DC. CSXT states that discontinuing the use of ATC when operating on the RF&P will provide a standardized operation across all CSS-equipped CSXT locomotives, enhancing reliability and safety. This standardization will enhance safety by reducing maintenance due to failures, train crew cutouts, and line of road equipment failure. CSS with the ATC segment removed will still stop the train if the locomotive operator does not acknowledge any signal downgrade, even if the positive train control (PTC) system is cutout. CSXT implemented the I-ETMS PTC system on the RF&P in October 2018. Wayside signal cab generators, locomotive cab signal equipment, and automatic train stop will remain." 

https://www.federalregister.gov/documents/2020/11/05/2020-24558/notice-of-application-for-approval-of-discontinuance-or-modification-of-a-railroad-signal-system

 

Can someone ‘decode’ the last sentence, above ?

What is it that is being discontinued?

Is there a ‘typo’, somewhere?

W.
Former MM, Pot. Yard, RF&P
1980 - 1990

Posted from iPhone

Only the speed control function of the cab signals (an onboard function) will be retired,  Cab energy will remain on the rails, effectively converting the "Automatic Train Control" (ATC) system to an "Automatic Cab Signal " (ACS) system, to utilize the regulatory terminology.

Logical move.  ATC speed control completely superfluous in a PTC environment.



Edited 2 time(s). Last edit at 11/24/20 05:47 by TractiveEffort.

Thanks for the clarification..

I ‘GET’ the useless redundancy,
And the need to comply with the
need for the formal request to document & to discontinue the older technology..

So the “old” system used 60-cycle* carrier frequency, for the cab signals, so is CSX still
required to use the RF&P “equipped” locos as ‘leaders’,
or can any PTC equipped loco
be used in the lead...

Does PTC replace cab signals?

When will ‘cab signals’ no longer be
required?

W.

* Original PRR carrier frequency had been 25- cycle, the entire electrical circuitry on the ‘corridor’
had been converted to 60–cycle
Frequency by Amtrak...

Part of the reason the GG1s became obsolete, along with their
Old main transformers, etc.

Posted from iPhone

wcamp1472 Wrote:
-------------------------------------------------------
> Thanks for the clarification..
>
> I ‘GET’ the useless redundancy,
> And the need to comply with the
> need for the formal request to document & to
> discontinue the older technology..
>
> So the “old” system used 60-cycle* carrier
> frequency, for the cab signals, so is CSX still
> required to use the RF&P “equipped” locos as
> ‘leaders’,
> or can any PTC equipped loco
> be used in the lead...

CSX converted cab energy on the RF&P from 60Hz to 100Hz at the time of CR split/acqusition to allow ex-CR ATC-equipped locomotives to lead on the RF&P.  Additionally, CSX "integrated" their cab signals with PTC, so a locomotive equipped with BOTH cab signals AND PTC is required.

> Does PTC replace cab signals?

Not on CSX/RF&P.  As stated above, cab signals are an "input" to PTC on CSX (and NS as well).  UP did not integrate cab signals with PTC, holds a waiver allowing use of PTC in lieu of cab signals, and will likely begin retirement in 2021.  UP already retired ATS in favor of PTC on Chicago commuter lines.

> When will ‘cab signals’ no longer be
> required?

On CSX and NS, no plans.  On UP, soon.

> W.
>
> * Original PRR carrier frequency had been 25-
> cycle, the entire electrical circuitry on the
> ‘corridor’
> had been converted to 60–cycle
> Frequency by Amtrak...
>
> Part of the reason the GG1s became obsolete, along
> with their
> Old main transformers, etc.
>
> Posted from iPhone



Edited 1 time(s). Last edit at 11/24/20 07:31 by TractiveEffort.

To simplify this further, what CSX is requesting to no longer use the speed enforcement (overspeed protection) provided by the cab signal system, as that specific function is made redundant by PTC.

For context:
In traditional CTC territory, signal indications are provided to the locomotive by way of PTC wayside intermediate units, which provide a radio link between the signal system and the locomotive's PTC computer.  This is true at both home signals (interlockings) and intermediate (block) signals.

It is possible to have a cab signal system overlaying that which I've described above although I don't think anyone's done that (I could be wrong).  In many cases (NS and CSX), they have been able to avoid some infrastructure costs by eliminating intermediate signals thereby avoiding added costs associated to the PTC hardware needed there.  NS for example went to this type of territory in PA over the last few years. Called "cab signal no wayside" territory, the cab signal system is the only data source of signal information to the PTC computer, unless the locomotive is approaching a home signal (at which case that interlocking is likely transmitting via a PTC WIU as well).

 

JUTower Wrote:
-------------------------------------------------------
> To simplify this further, what CSX is requesting
> to no longer use the speed enforcement (overspeed
> protection) provided by the cab signal system, as
> that specific function is made redundant by PTC.
>
> For context:
> In traditional CTC territory, signal indications
> are provided to the locomotive by way of PTC
> wayside intermediate units, which provide a radio
> link between the signal system and the
> locomotive's PTC computer.  This is true at both
> home signals (interlockings) and intermediate
> (block) signals.
>
> It is possible to have a cab signal system
> overlaying that which I've described above
> although I don't think anyone's done that (I could
> be wrong).  In many cases (NS and CSX), they have
> been able to avoid some infrastructure costs by
> eliminating intermediate signals thereby avoiding
> added costs associated to the PTC hardware needed
> there.  NS for example went to this type of
> territory in PA over the last few years. Called
> "cab signal no wayside" territory, the cab signal
> system is the only data source of signal
> information to the PTC computer, unless the
> locomotive is approaching a home signal (at which
> case that interlocking is likely transmitting via
> a PTC WIU as well).
>
>  

I believe the RF&P -was- cab signal no wayside territory until the 90s or something when CSX added waysides to try and get the FRA to allow them to get rid of the cab signal system.  It didn't work out for them.  But now there's waysides anyway.

wcamp1472 Wrote:
-------------------------------------------------------
> * Original PRR carrier frequency had been 25-
> cycle, the entire electrical circuitry on the
> ‘corridor’
> had been converted to 60–cycle
> Frequency by Amtrak...
>
> Part of the reason the GG1s became obsolete, along
> with their
> Old main transformers, etc.

Actually, traction power on the entire corridor west/south of GATE interlocking on the Hell Gate (east of Sunnyside Yard) is still 25 cycle. I can't speak to the signal system, but traction power most certainly is still 25 cycle. The GG-1s were retired because they were old and their transformers contained PCBs. Since the Hell Gate and Metro-North were being converted to 60 cycle traction power, the GG-1s would no longer be able to operate east of New York, so their usefulness was reduced. But electrically, there was no reason why they couldn't continue to run west of New York.

Jim
 

Erie-Lackawanna Wrote:
-------------------------------------------------------

> >
> > Part of the reason the GG1s became obsolete,
> along
> >. But electrically, there was no reason
> why they couldn't continue to run west of New
> York.
>
> Jim

So let’s light one up and have a fantrip! 😃😃

As per the CSX rulebook, the ATC system on the RF&P appeared to only enforce a minimum brake pipe reduction upon cab signal changes and did not include hard speed control.  Cab signal based speed control has always run counter to safe train handling for long freight trains.  The only place it was implemented was on Amtrak via a system known as Locomotive Speed Limiter, which was a gentler version of the ATC installed on passenger trains.  Back to the RF&P, Amtrak trains would run with their ATC systems cut in, but that was never mentioned in the CSX documentation I have access to.  Up through about 2002 there were also references to some quirks of the RF&P cab signals in that the code could drop out within interlocking limits on diverging routes (likely an RF&P cost saving measure).  An ATC system with hard speed control would not work very well under such conditions. 



>
> I believe the RF&P -was- cab signal no wayside
> territory until the 90s or something when CSX
> added waysides to try and get the FRA to allow
> them to get rid of the cab signal system.  It
> didn't work out for them.  But now there's
> waysides anyway.

I am not aware of the RF&P running a non-wayside operation.  The RF&P did install their own wayside signals between 1985 and the CSX purchase in what I believe was a system wide CTC upgrade from ABS. 

FROM ABOVE:  "As per the CSX rulebook, the ATC system on the RF&P appeared
to only enforce a minimum brake pipe reduction upon cab signal changes and
did not include hard speed control. "

Aux contraire, mon ami..

( Note: the below explanation is the 'way it used to be'...current operating rules & practices may vary)

Upon passing a more restrictive signal on the RF&P, the engineer had to
'acknowledge'  ( reset switch) the more restrictive aspect  AND must immediately
initiate a sufficiently-deep  BP reduction to 'forestall' a penalty reduction..

At Potomac Yards we performed cab signal testing on all departing RF&P as well as ConRail  locos.
( ConRail ATC, on their freight 'motors',  DID NOT APPLY brakes, once the penalty & warning time
period  [ 6 seconds?]  ran-down , only the cab signal whistle sounds incessantly, if no  braking application
is initiated). There was no penalty application of the train brakes, as on 'equipped' passenger trains.

On the RF&P( (PY)  departure testing/confirmation process we manually controlled the departure
test sequence & set "signal generator"  to  verify faithful way-side signal repetition.  
The final test step was to ignore 'acknowledging' the change to more restrictive indication ---
thus, initiating a penalty application....for testing purposes   ( The acknowledging process involved
both operating the 'acknowledging lever'  ( electric switch) AND beginning a brake pipe reduction...
failing to make a 'test'. BP reduction, results in a full-penalty application ... that was one one of our departure
test steps..

The penalty application was a two-stage BP reduction-process... once initiated, it could not be 
interrupted, cancelled or overridden.   The 1st stage was an involuntary, full-service 
brake pipe pressure 'reduction' down to a 20-pound reduction.... that self-lapped
at the 20-pound ( reduced) level.

After an approximately 30-second delay, the system resumed exhausting brake-pipe
air, at a 'service-rate' of reduction....that lasted all the way down to zero on the
trainline air gauge.  ( "Service Rate" is a specific, controlled rate of air-exhausting controlled
by engineer's brake valve.  Service rate is slow, steady and controlled venting of air --
to prevent individual freight car control valves from being activated to apply the brakes
at an 'Emergency' rate of air flow exhaustion.).  UDEs are a subject for a later discussion.

Those two rates of flow are distinctly different & precisely regulated --- so that trains
over a mile in length can be reliably controlled form the lead engine.
( Two rates?  "Service Rate" & "Emergency Rate"....)

On the road ( signalled territory) , once the RF&P penalty application was initiated, it could NOT be
prematurely prevented --- from the involuntary draw-down, to zero BP pressure.

In order to 'recover' from the penalty application, the engineer must place the automatiic 
brske valve handle in the 'Emergency' position, and leave it there until the 
1-minute time delay ( specific volume timing reservoir) was satisfied.

Any urgency at attempting to (prematurely) 're-capture' trainline control, before the "1-minute delay", 
"failed" the attempt, and a 'fresh 6O-second' recovery time-delay period was initiated.  
Patience in recovery mode is a virtue...

Once, the 60-second  ( uninterrupted) recovery period was satisfied, the venting of the BP ceased,
and the engineer can move the automatic brake valve handle back to 'Running' position,
and recharge the entire train, the cars'  Auxiliary Reservoirs and their Emergency Reservoirs  
must be fully RECHARGED before attempting to resume the trip.

To summarize:  The Penalty Application of the brakes starts an involuntary application at a controlled-rate,
that initially sets the train brakes at a 'Full-Service' application ( I.e: a 20-lb reduction).
That initial reduction laps-off, & holds steady for about 30 seconds.

After the 30-seconds runs-down, the brske-pipe resumes exhausting, at a 'service rate'...
until the trainline brake-pipe is entirely exhausted.

The Engineer can only then, begin the recovery of trainline air pressure.  
But, first, he must first place the Automatic brake handle in the 'Emergency' notch
( all the way 'forward') and leave the handle in that notch for at least 60-seconds...

At the end of the 'recovery timer' reservoir, the venting of the BP ceases, and the engineer 
can move the brake handle out of the 'Emergency Notch' ( colloquially called "The Big Hole"),
begin to re-charge the entire train.

All of those steps must be followed assiduously, or the recovery process must be repeated
( from the start) by restoring the brake handle to 'Running notch', then place it in 'Emergency notch',
for the 'new' , full 60-seconds time-delay.  After the end of the 60-second time-delay you can try to
recharge the entire train, it's mile long pipe, and all the cars' individual reservoirs.

At the departure yard, our electricians had to ensure that the RF&P cab signal system functioned
successfully, at each stage of the check-out procedure, including a "full penalty application test"
and all the necessary steps to recovery   ---- each step must perform as intended, or the loco 
cannot be used a a 'leading' unit.
 
The 'penalty application' was always at a service-rate of brake-pipe reduction, NOT Emergency
rate of air discharge, and at the second stage if the penalty, air was exhausted from the train
all the way down to BP pressure of 'atmosphere'..

The service rate penalty could not be interrupted until all the penalty stages were completed
in proper sequence.  

On the related communications with the dispatcher, a crew had "some 'splainin' to do",
if their train was delayed by a penalty application.   Our electricians always submitted
a signed, successful departure 'Test Record' slip in the cab, with file copies for the
Master Mechanic's office.   

I never had an incident related to a failed RF&P cab-signal 'tested locomotive'.
CR locos, cab signals more often malfunctioned, and had to be 'switched-out',
with a compliant lead locomotive.  

( Note: when electricians found CR cab-signal whistles  'taped-up' or otherwise
tampered-with, our mechanical depot. crews stripped the intended silencing materials
from CR cab signal whistles.  Muffling was NEVER a successful procedure with Main Reservoir 
air pressure ( 140-psi);  it shredded the tape cover the whistle-port.... the tape was successful 
at dampening the extremely shrill frequencies emanating from the resonating whistle pipe.).

​W.

To be proofed, yet..







 



Edited 1 time(s). Last edit at 01/04/21 12:03 by wcamp1472.

Adding a little more...

Where I work we have CCS territory. Once PTC is logged in, we are required to cut out CCS.

What we were told, is due to the air line controls, there could be a conflict that may induce or prevent a penalty brake application with both systems cut in.

I can’t speak for that part of CSX, but the major players all pretty much use the GE/Alstrom/Harmon equipment as well as ITMS for PTC, and I’d have to imagine the same would be required (as far as the big carriers go).

On CCS equipped track, CCS leaders are still required in case PTC fails and is required to be cut out (the FRA requirement of having cabs hasn’t gone away for equipped track).

The carriers are already getting ready to request that CCS be disabled with the PTC required mandate.

More detail: 

https://downloads.regulations.gov/FRA-2020-0084-0001/attachment_1.pdf

As an earlier post stated on CSX and NS cab territory with PTC they don't have PTC WIUs on intermediates or cab block points only on the home signals. RF&P has wayside intermediates but they don't have WIUs installed on them only the home signals do - they are relying on cab signals alone to provide the intermediate signal input to PTC. They claim they're going to be able to just update the software on their locomotives to disable the ATC speed control if they get approval. One major reason they want to do it (according to their letter) is that a malfunction with the ATC side of things can cause them to have to cut out the cab signal unit altogether which ultimately ends up causing them to cut out PTC. With cabs cut out PTC loses its intermediate signal input and will assume a restricting aspect is present. Typically then the dispatcher will have the crew cut out PTC. They are arguing this will reduce cutouts of PTC.



Edited 4 time(s). Last edit at 05/25/21 19:56 by lordsigma.