The carriers seem to be on a kick to get on board with PTC…but I don’t understand what’s so new or great about it. Southern had in cab signals way back in the 70s…at least their ads in Trains said they did. And CN I’ve read has a system that over rides the engineer and brakes the train in the event that a signal is missed…so what’s the big deal with PTC?
The current cab signal systems are too expensive, and there are several older incompatible systems out there. PTC will have common protocals but each company can make its own equipment.
For example all UP locomotives in order to lead on both the old UP Overland Route and the former C&NW mainline have to be equipped with two different systems, and if the same locomotive were to lead from Chicago to Milwaukee via Kenosha, WI it would need a third system. Two of the systems predate WW2. As a side note the ATS system (Chicago to Milwaukee and Janesville, WI) is only installed on former C&NW SD40-2 and C40-8 locomotives, so that some of them must be kept captive to the area in order that sufficient leaders are available. In practice all of both groups are kept captive because the old equipment fails and spare locomotives are necessary. NS and CSX also have their own cab signal territory (the equipment isnt compatible with the C&NW system or UP system), and Amtrak has still another system on the NEC. Then there is the systems installed on the Porter, IN to Kalamazoo, MI line. And finally the system installed in Central Illinois around Bloomington on the old Alton RR. To my knowledge absolutely none of these systems is compatible with any of the others.
Much of the NE Corridor system dates from the PRR electrification of the 1930’s. It is the system that dual-power locomotives must use to enter Penn Station NY from the West Side Line. But on Metro North tracks, north of Spuyten Dyvil, a different system is used, and thus the Amtrak locomotives must have equipment that works on both. The new Metro North system does not employ any lineside signals except at switches where they are conformation of the cab signals.
These days, ATS is used only as far as Harvard or Kenosha on the respective lines.
I think (Jeff would be a higher authority than I) virtually all newer UP power can operate over ex-CNW ATC territory. The newer CNW units (Dash 9s), and perhaps some of the earlier ones, were capable of operating over CNW’s ATC and UP’s CCS-CS territory.
The trains to Janesville now employ UP-original wide-nose Dash 8s regularly, so those must have been equipped with ATS.
And now, between Lake Bluff and Kenosha, there are cab signals, which I presume are of the UP variety. They are to be used on freight and business trains when the lead unit is equipped with cab signals (if that’s not the case, ATS applies–but this means you no longer need an ATS lead unit on Oak Creek coal trains).
The government is on a kick to get PTC installed. From most of what I have read, the carriers aren’t sure the cost of PTC is worth the benefit. They use the argument that with PTC they can go to one person crews. In the last contract talks, they tried to start to go to one person without PTC. If they had been (or are in the future) able to get one person crews without PTC, they would fight tooth and nail against PTC because of the cost.
The difference between PTC and existing enforcement technology (ATC, CCS, ATS, ETC) is that PTC also will enforce speed limits, including temporary restrictions, and limits of main track authorities. Also, with most of the current ones, as long as you acknowledge the signal, the system will allow you to keep going without doing anything else. You could go into a collision at 70 mph as long as you acknowledge the signal changes. PTC will take action if the engineer doesn’t.
Carl is right about the later UP engines being dual CCS/ATC equipped. Even some older power after the merger, from both UP and CNW were equipped to run on either system.
Jeff
The railroads are actually anxious to get PTC installed after decades of fighting the concept. The NTSB has been pushing for PTC every year but the RR’s have told the FRA it was 1) too expensive, 2) not relieable and 3) not necessary in spite of what the NTSB was finding in their accident investigations.
So what is the big change, safety? No, crew reductions. As soon as the industry settles on a common system and installation begins anew they will be pushing the operating unions on the one person crew line again. The quickest way to get the RRs to spend money is to allow them to think it will yield a huge savings in personnel costs.
The biggest difference between PTC/PTS and all the other schemes currently in widespread use in the US and Canada is the PTS uses predictive enforcement of movement authority. That is, it will make the train stop before it reaches the end of it’s movement authority.
Most of the cab signal systems I’m familiar with require only some reaction or will enforce a reaction to a downward signal aspect change, but none can enforce a movement authority limit represented by a stop signal.
oltmannd is on point.
PTC provides predictive braking, cab signals do not.
PTC has real-time knowledge of train characteristics including tonnage, maximum allowable speed, dynamic braking curves, etc. Cab signals do not.
PTC predictively enforces permanent and temporary speed restrictions not associated with a signal aspect (e.g., Form As, permanent curve and turnout limits), cab signals do not
PTC doesn’t require a humonguous investment in fixed plant and locomotive hardware like cab signals do.
PTC can be updated with environment changes in real time; cab signals require a months-long and expensive reconfiguration of the circuitry
PTC is a full-fledged train-control system that can overlay on CTC, TWC, OCS, DTC, or anything else, and can be used for many things. Cab signals are only a very expensive method of delivering signal aspects into the cab.
RWM
Maybe I should have made the following question part of a new thread in my well-known “ignoramus” questions, but I must ask: does PTC require CTC?
Not a dumb question.
No, it does not require pre-existing or new CTC. In fact one of the most attractive characteristics of PTC is that it can provide virtual CTC (with the addition of DTMF-type power switch machines) at a fraction of the cost. Fertile field for PTC installations are (1) dark-territory lines with moderate traffic that can’t justify CTC on a cost-benefit basis for the capacity increase CTC would provide, and (2) as a stand-alone “safety critical” train-control system, and CTC lines with both passenger and freight service, as an overlay to enforce speed restrictions and authority limits.
PTC is now more commonly referred to as CBTC, for Communications-Based Train Control. PTC is a generic category that encompasses a broad array of systems. METRA (Chicago) is in the design stage of a CBTC overlay on CTC primarily to add safety. UP, BNSF, and NS are all in design stage for CBTC primarily to add capacity and safety in dark TWC/DTC territory.
RWM
From prior posting by Railway Man: “METRA (Chicago) is in the design stage of a CBTC overlay on CTC primarily to add safety.” **
** Is that the installation Wabtech is handling? - al
Yes – WABTEC is the designer and manufacturer of the system; METRA will install.
Thanks!