Slow and Easy

[Overmod]

Jen: this general subject can be a bit convoluted. E-mail me if you have continuing techie questions.

Cab signals and train control systems are two separate things, although you naturally find the two of them together in many cases.

The Government mandated 'automatic train control' in 1920, as part of the legislation that returned the railroads to private control. My research indicates that it would have been highly likely that a continued USRA would have pushed this as a priority after settling in after WWi. There was supposed to be a period of testing and service confirmation before the law applied to all railroads -- every Class 1 was supposed to have at least one piece of track equipped and operating by a relatively early date (don't have my thesis in front of me, but IIRC that date was either in 1923 or 1925). The absolute mandate made for some very interesting companies and developments in automatic train-control design in the 1920s, with one very interesting effort carried on by Frank Sprague (the inventor of MU control and other interesting things, who had been researching ways to do it since he was a boy). Essentially, the Depression killed most of the hope that ATC of some kind would be implemented everywhere; the ICC ruled in 1947 that ATC would only be required for train speeds of 80mph and above (which is why the 'speed limit' is that odd-looking 79mph) and that limit continues in effect to this day.

Meanwhile, cab signals were not really an essential part of an ATC system, which basically alerted or braked when an appropriately-restricting signal was 'violated'. Early cab-signal experiments were used in situations where there were short or variable headways and it would be too expensive or restricting to put in the appropriate number of lineside signal devices, and also in some areas where operating profile or visibility made external signals undesirable -- I remember that one such installation was made on the Belvidere-Delaware line in the '20s because of frequent heavy fog problems, and I have little doubt that the experts on this forum can provide you detailed examples. These systems are usually 'repeaters' for the main signal system, although many modern lines dispense entirely with the expensive wayside signal apparatus (IIRC, the New Tokaido Line was among the first designed this way).

There have been fairly interesting discussions of the rise and fall of the NYC train-control systems in some of the discussions of the National Transportation Safety Board, which has been conducting particular investigations into mandatory PTS (positive-train-stop) systems -- note that this is a very different thing from positive train "control" systems. The original system dated from the late '20s, and was essentially still operating on the same technology into the early 1970s, at which point the spare parts and maintenance were tremendously expensive, but Penn Central's famous deferred track maintenance pretty well made high speed "superfluous". I don't remember the exact procedure that was used to grant PC the right to stop using the system, but it's available in reports from NTSB (I'll see if I can find my copy of the relevant background paper).

ACELA, as of my last look at the system technology, was using ACSES (which you can research on the Web faster than I could try to explain it, and get better answers...)

[Randy Stahl]

I wonder how many of todays railroaders would have had a difficult time with the consolidated code?
Randy (A train is superior to another train by.......)

[mudchicken]

Missy Mooks has copies of current GCOR and NORAC signal aspects in her possession. Was NOT trying to imply these were CB&Q. I was cleaning out the nest in the office and thought Mooks could have fun with 'da stuff. And while on the subject of "office", I have not been there too terribly much on account of life at Utah Junction (CB&Q was there too, Denver to Broomfield/Burns Jcn to Erie branch) and an office computer that has rigor-mortis.

Muddy Feathers @ home
(and you ought to see the mud/adobe? on the truck!)

[ericsp]

QUOTE: Originally posted by Mookie

My sheet on signals shows cab speed.

I hope that is the same as the train speed.

[jeaton]

A couple of things. If you look closely at the January Trains Map of the Month showing New York Central system routes you will see that the type of signaling and train control is shown for all their routes. ATC was very extensive. Also, the Milwaukee and the Illinois Central had ATC.

Jay

[Sterling1]

QUOTE: Originally posted by Mookie

So maybe these signals are "old" ones? Maybe the Chicken is trying to confuse me? Maybe the Chicken is in big trouble!

He has been mysteriously missing and I will need to check into that!

Find that chicken and wring him hard!
Was your question specific enough for him to give you nonsense?

[dwil89]

QUOTE: Originally posted by jeffhergert

The Union Pacific still uses two types of cab signals. From about MP 7.5 at Omaha to Ogden, Utah the UP uses the 4 aspect coded cab signal. From the north end of Council Bluffs to Chicago the UP still uses the old CNW 2 aspect Automatic Train Control.
The CCS aspects are clear, advance approach, approach and restricting.
The ATC aspects are clear and restricting.
Jeff

NS still uses Cabsignals on the old PRR main through Pennsylvania....Harrisburg on westward. CSX uses cabsignals on the Old Boston and Albany Line that runs from Selkirk Ny to Boston, there may be some other examples of Cab-signal use elsewhere by either CSX or NS, but on the former Pennsy main, you will never see foreign power lead in Cab Signal Territory, except for CSX ex-Conrail locomotives, or Cab-signal equipped CSX heritage units. Dave Williams http://groups.yahoo.com/group/nsaltoonajohnstown

[jeffhergert]

The Union Pacific still uses two types of cab signals. From about MP 7.5 at Omaha to Ogden, Utah the UP uses the 4 aspect coded cab signal. From the north end of Council Bluffs to Chicago the UP still uses the old CNW 2 aspect Automatic Train Control.
The CCS aspects are clear, advance approach, approach and restricting.
The ATC aspects are clear and restricting.
Jeff

[oltmannd]

There was a time when the ICC mandated that the class 1s install cab signals or train stop on their busiest divisions. Have no idea of the details of the rule, but most roads had something, somewhere.

BNSF still has some trains stop equipment on the old ATSF - It's why the SW Chief is allowed 90 in spots.

NYC had train stop most of the way to Chicago. They allowed 90 for passenger trains in many places. It lasted into Penn Central.

[kenneo]

Mook

UP, Q, and PRR all used cab signals on some portion of their territories, but purchasing them and maintaining them was real spendy, so they were only used where safety was a high profile affair. The Q only used them in the Surburban Zone out of Chicago. I'm not sure where the UP used theirs, but I only remember seeing them in passenger locomotives and some F units. The PRR used theirs between NYC and W,D.C. and Philly and Harrisburg.

I know other roads had them, but I can't recall who or where.

And that rascally chicken, he gave you a piece of history. If you want to know what the signals mean today, look in the GCOR site. There is at least one whole page with pictures.

[Anonymous]

Everything around these parts is either CTC or OCS, though many of the CN and BC Rail locomotives still around have cab signals on them, but none of them are in use, that I know of.

[mustanggt]

If i'm not mistaken, Amtrak's acela trains have cab signals. Or atleast I think they do[?]

[edblysard]

Havent seen cab signals in any BN, Santa Fe, or BNSF locomotive.
Mookie, go by the signals in the book, their aspect and indication is what BNSF uses.
Track speed on the BNSF will be found in their timetable, and special instructions.

Ed
[:(!]
[:)]
[^]

[Mookie]

So maybe these signals are "old" ones? Maybe the Chicken is trying to confuse me? Maybe the Chicken is in big trouble!

He has been mysteriously missing and I will need to check into that!

[Randy Stahl]

I think only the Burlington suburban trains had cab signals. I don't recall seeing cab signals on recent BNSF engines.
Randy

[Mookie]

Randy - the maps are just of the Q - for looking at only. The signals are the current ones in use. I think....So do current locomotives have cab signals?

[Randy Stahl]

I don't recall the Q as having cab signals????Toss the GCOR book, the Q used the consolidated code.
Randy

[Mookie]

Continuing Education Class will now start.

We must go slow and easy because some of us confuse easily.

I am looking at the signals sheet that the muddy chicken gave me along with maps of the old CB&Q tracks in and around Lincoln. I checked my GCOR notes that Ed B gave me and notes on signals and it's all Geek to me - still!

So will ask only one question for now. My sheet on signals shows cab speed. This means exactly that? The signal is in the cab rather than on a signal stand?

Moo