Western Railroad Discussion > Question: timetables in the PTC era

Last week I finished my first term teaching Introduction to Railway Engineering to state university (mostly) civil engineering majors. To help them understand how the infrastructure fits into the bigger picture of traffic, rolling stock, and operations I showed examples of, and passed around, rule books and employee timetables that I had from past decades. For much of what I briefly covered on dispatching, communications, and signaling, I said "And this will all change with PTC" (though I realize PTC is generally being layered over previous systems, not replacing them).
So, can any TO folks provide --even images of a few pages-- ETTs that reflect PTC being in operation?

Here are two pages from the Metrolink (Southern California) employee timetable. One the first, note the only real change is the addition of "PTC" in the Method of Operation column. Page 2 is the first of several pages specifically added for PTC.

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So how will anything change with respect to timetables because of PTC? PTC simply, at least in theory, prevents collisions between trains and enforces speed restrictions. Dispatching and pretty much everything else remains as it is. And why would anything in a timetable change, other than possibly denoting where PTC is in effect.



Edited 1 time(s). Last edit at 06/21/18 16:59 by Railbaron.

Honestly the addition of PTC doesn't really change much in a UP timetable. Just a small addition that says PTC between Point A and Point B... It's all of about 2 new lines of writing on a subdivision page which in itself can be pages long.

My class 1 just puts a item four in the timetable specific rules info saying Safety Overlay Systems In Effect : Positive Train Control (PTC)

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"Method of operation" refers to main track authority, which is Rule 6.13, CTC, and CTC 2MT, depending on where you are on the subdivision. In this instance, "PTC" is a signal system rather and not main track authority.

EtoinShrdlu Wrote:
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> "Method of operation" refers to main track
> authority, which is Rule 6.13, CTC, and CTC 2MT,
> depending on where you are on the subdivision. In
> this instance, "PTC" is a signal system rather and
> not main track authority.

PTC belongs in the "Method Of Operation" column because its alters how one operates, in this case while in CTC territory. While PTC cannot expand your authority, it sure can limit it. ABS (Automatic Block Signals) is in the same column for the same reason.

Thanks to all for your comments, and especially the sample pages. From what I hear on the scanner, at least here on the Coast and Santa Barbara divisions, with PTC in its trial stages, there's a lot of "permission to continue anyway" and discussion on how to reboot, and to download additional data for additional track segments.

Ha. I just saw "Berdoo" officially in print for the first time.

SB Sub, as I recall was/is one of the test beds.

There should be no waiting for track segments going down the road - it’s all loaded into the computer at crew change points, or when it needs to be initialized.

I can run over three different subdivisions at 300+ miles, and the only time the segments are downloaded is when I get on a train.

Now, there are times when a sync error can occur, and that’s when the PTC onboard computer cannot talk to the server to make sure all the bulletins and other information cannot be compared.

In that case you reduce speed and hopefully it finds another tower or relinks to the server.

> ABS (Automatic Block Signals) is in the same column for the same reason.

This depends on the railroad and the era of the ETT.

Edited to add:

"Method of operation" refers to how main track authority is granted, not the presence or absence of ABS. In certain situations, the indications of ABS signals are used to grant main track authority, but the ETT must specifically state that this is the case. In CTC, it is the DS who is the origin of main track authority, which he grants via signal indication (or verbally). This relegates PTC to being no different than ABS in the days of train orders and schedules: an add-on. The yellow and red indications of ABS signals did place certain limits on train's movement, but they couldn't grant MT authority unless the RR said so. Using ABS signal indications to authorize train movements on DT is a CB&Q innovation dating from 1900. Just like with ABS, which is also present within CTC limits, no railroad is going to say PTC can grant MT authority within CTC and Rule 6.13.



Edited 2 time(s). Last edit at 06/23/18 19:38 by EtoinShrdlu.