Eastern Railroad Discussion > Foreign leaders on NS Middle Division ??

With PTC, does anything other than NS get to lead now ?

UP out west is now a free for all that way like everywhere else.

Bill Miller
Galt, ON

Don’t believe so. Pretty sure they still need to have cab signals. Certainly haven’t seen any.

Posted from iPhone

There are also varying types of PTC.

They require cab signals as NS removed all former intermediate lineside signals other than interlockings.
Go

Nope, as was stated still need cab signal equipped leaders.

Posted from Android

Some CSX units can lead on the Middle Division.

There's about 30 (wild guess) railroads listed on a CSX engine that you can log into and run lead...if the railroad you are on is not listed you can't run it there. And pretty sure if you got Wabtec you can run awywhere but NEC...and to the extent that there's more than one kind of PTC that distinction is ONLY made by outsiders....PTC is Wabtec IETMS and everything else is whatever it's brand name is. 

engineerinvirginia Wrote:
-------------------------------------------------------
> There's about 30 (wild guess) railroads listed on
> a CSX engine that you can log into and run
> lead...if the railroad you are on is not listed
> you can't run it there. And pretty sure if you got
> Wabtec you can run awywhere but NEC...and to the
> extent that there's more than one kind of PTC that
> distinction is ONLY made by outsiders....PTC is
> Wabtec IETMS and everything else is whatever it's
> brand name is. 

Wabtec's I-ETMS has been overlaid on the NEC, so freights don't have to have Amtrak's system. The "different kinds of PTC" thing made me chuckle, as interoperability was a big factor in PTC.

Posted from Android



Edited 1 time(s). Last edit at 03/26/23 08:33 by bioyans.

There *are* different kinds of PTC.  Amtrak's ACSES system (also used by NJT, SEPTA, etc) is not the same as Wabtec's iETMS.  And not all flavors of iETMS are equal.  Cab signals are still required on much of the former PRR in PA - from Harrisburg to Pittsburgh and thence to at least Alliance, OH (and I believe the rest of the way to Cleveland).

The only benefit I can see is a backup in the event of PTC failure, either onboard the leading loco or to the system.  Am I missing something ?

SZ

Steinzeit2 Wrote:
-------------------------------------------------------
> The only benefit I can see is a backup in the
> event of PTC failure, either onboard the leading
> loco or to the system.  Am I missing something ?
>
> SZ

Yes, PTC is the overlay for the Cab Signals not the other way around. The PTC is not what gives you authority to proceed, the cab signals do. Also having the cab signals has allowed all intermediate signals to be removed saving in costs associated with maintaining them.

Posted from Android

OHRY Wrote:

> Yes, PTC is the overlay for the Cab Signals not
> the other way around. The PTC is not what gives
> you authority to proceed, the cab signals do. Also
> having the cab signals has allowed all
> intermediate signals to be removed saving in costs
> associated with maintaining them.

Exactly.

This is still surprising, given what a notoriously [ ahem ] "thrifty" outfit NS is.

A.  I realize the wayside portion has to stay in service, because the CCS in the rails also functions as the track occupancy etc circuitry -- so the only savings is from the onboard equipment:  maintenance, provision of a cab sig leader, and, significantly I would have thought, the requirement -- I presume it still exists --  for the daily check.
B.  The wayside bungalows that "replaced" the intermediates are inputting the same state of track to both the CCS output and the PTC side.
C.  As far as movement authority, clearly the more restrictive of CCS or PTC -- usually the latter of course -- governs.  You could have a Clear in the Cab, but if the PTC says Stop and Stay -- due to Work Limits Authority, for example -- you stay,  so what does the CCS buy you ?

In my opinion, it "must" be a reliability issue.  I see UP said [ : "Goodby Cab Signals..." in their 2/6/23 ed of their inhouse pub Inside Track  ] "...in 2021 PTC reliability warranted regulators to approve the full discontinuance of cab signals in mid-2022 ";  for the prior five years,[ the FRA ] apparently still required cab signal locos to lead due to PTC reliability problems. Perhaps NS is under a similar situation.

SZ

Steinzeit2 Wrote:
-------------------------------------------------------
> This is still surprising, given what a notoriously
> [ ahem ] "thrifty" outfit NS is.
>
> A.  I realize the wayside portion has to stay in
> service, because the CCS in the rails also
> functions as the track occupancy etc circuitry --
> so the only savings is from the onboard
> equipment:  maintenance, provision of a cab sig
> leader, and, significantly I would have thought,
> the requirement -- I presume it still exists -- 
> for the daily check.

The daily check still exists.  There is an additional savings - while the wayside bungalows needed to be replaced, for home signals and intermediates, there is no need for intermediate wayside signals. So there must have been some savings in signal hardware.  

> B.  The wayside bungalows that "replaced" the
> intermediates are inputting the same state of
> track to both the CCS output and the PTC side.

Not quite. The intermediate wayside bungalows provide the output to only CCS.  The waysides do not report over 220mhz radio or via the back office to PTC.  The CCS onboard computer relays its status to the PTC computer via an interface cable.

> C.  As far as movement authority, clearly the
> more restrictive of CCS or PTC -- usually the
> latter of course -- governs.  You could have a
> Clear in the Cab, but if the PTC says Stop and
> Stay -- due to Work Limits Authority, for example
> -- you stay,  so what does the CCS buy you ?

Answer: track occupancy and speed.  As you point out earlier, the CCS can be more restrictive than PTC, and the other way around is also true as described in C.  You could have signal authority from interlocking to interlocking on the PTC computer which wouldn't know that you're following blocks behind another train.   (See my answer to B)  That speed/occupancy is conveyed solely via CCS. (I'm using that term loosely here; if you get an Approach cab signal code one could presume that you're following behind another train, but that information can only be inferred and is not a given.)

> In my opinion, it "must" be a reliability issue. 
> I see UP said [ : "Goodby Cab Signals..." in their
> 2/6/23 ed of their inhouse pub Inside Track  ]
> "...in 2021 PTC reliability warranted regulators
> to approve the full discontinuance of cab signals
> in mid-2022 ";  for the prior five years,[ the
> FRA ] apparently still required cab signal locos
> to lead due to PTC reliability problems. Perhaps
> NS is under a similar situation.
>
> SZ

I don't know if that conclusion is fair. UP and NS cab signal systems are not identical.  Furthermore, in many cases, it appears that there are some locations with shorter intermediate blocks as a result, which has the impact of allowing for greater capacity through that area. Block length is a determining factor in any signal system design.

JUTower Wrote:
-------------------------------------------------------
> Not quite. The intermediate wayside bungalows
> provide the output to only CCS.  The waysides do
> not report over 220mhz radio or via the back
> office to PTC.  The CCS onboard computer relays
> its status to the PTC computer via an interface
> cable.
>
Ah, that's what I was missing -- there is no space radio or hardwire link out of the intermediate waysides in CCS territory.  Thank you !  UP, it would appear, arranged their intermediate signal status to be conveyed as in non-CCS territory.  It would be interesting to know why NS took the approach it did -- terrain, cost, message density in high traffic areas, etc. -- given the costs of "non-standard logic validation" [ or whatever the phrase is ].  I wonder if there's a paper somewhere out there on this.

Best regards, SZ