>>> Unlike car traffic signals, which have limited nationwide meanings, "there are
>>> dozens and dozens of signal combinations," which can hold different meanings
>>> under tracks owned by different railroads, Sumwalt said.

>>> If this is indeed true, it seems like it's a massive accident waiting to happen!
>>> Has no effort ever been launched to address this nightmare? The NTSB seems to
>>> be the most logical agency to do so.

>It most emphatically is NOT TRUE! At least only very rarely. Not only that, but GCOR vs NORAC signal rule differences are superficial and minor.

I'm not so sure I would characterize the differences in meaning of a red over yellow as either "superficial" or "minor": "restricting" under NORAC (proceed at restricted speed), "diverging approach" under GCOR (proceed at anywhere from 10 to 40 mph on diverging route, depending on the location and the railroad).

>The average railfan couldn't even tell which is being used at any given site

What we need in these cases are armchair expert filters.

>The FRA for at least 60 years that I know of, has taken high exception to oddball signal meanings everywhere they have been found - with fines and shutdown orders to follow if compliance was not prompt.

True. About 25-30 years ago, after a wreck on the Frisco, the FRA said that distant signals could no longer display a green aspect.

>Locomotive engineers are thoroughly professional and technologically qualified to do what they do. Moreover, they are specifially tested and qualified on every inch of track thay operate on - thoroughly familiar with the location and capability of every appliance, constraint and circumstance on the line.

Unfortunately, this isn't exactly the case with Amtrak's training program. It used to be, but not any more. Up until 10-12 years ago, Choo-Choo U didn't even teach the GCOR, and essentially everything west of Chicago is GCOR. They do today but in a pi**-poor way and fight with the local crewbases and Divisions who try to make up for the deficiency.

>The current fancy buzz-word is PTS (Positive Train separation), which generally refers to newer technologies (satelite and radio ranging) being overlayed over existing signal systems. Of course the FRA and the railroads are very reluctant to impose it because of the billions it would cost to cover all mainline trackage and because it is still experimental, unproven, and generally still unreliable where it has been tried.

These are good reasons why the NTSB can make only recommendations, not change nor promulgate regulations. PTS is really pie in the sky. Think about it: how possible is it to keep trains weighing in the range of 18,000 TONS absolutely from running into each other? How far do you keep them separated? If too far, then one stopped train with two others stopped behind the first can bring your whole operation to a stand still. The only sure way to keep trains from running into each other is not to set any of them in motion in the first place.

The current trend in railroading is to treat your employees like s**t and drive off the experienced ones--because they work for a higher rate of pay. This creates the situation where the remaining smart ones move on somewhere else where the working atmosphere isn't so hostile, the dumb ones get fired, and all you're left with is crashing mediocrity.

>However, anymore, virtually every existing mainline track circuit in America is already an electronic coded track circuit, or soon will be under normal re-capitalization programs. Even those not yet electronic are still coded. The main difference between lines with operating cab signal/ATS systems and those without, is how the coding is arranged.

Most ATS doesn't use codes but wayside magnets or trip arms. ATS can no longer be introduced as a new installation, per the FRA.

>It is therefore possible using existing off the shelf components, most of which are already installed, to cost effectively re-arrange the coding. This could extend current cab signal territory almost universally - and without undue financial burdens.

Cab signals won't work unless the codes in the track are AC, and there is still a lot of track circuits around coded with DC pulses. Besides, Electrocode is prone to it's own quirks (it's notorious for failing to detect the presence of things like light engines and engines with only 4-6 cars)

>ABS/TWC REALLY on code lines nationwide, or is it still magnetic in some locations?

ABS = automatic block signals. If coded track circuits are used, it's only to replace the line wires and not for dispatcher control of signals.

TWC = track warrant control, which has nothing to do with the presence or absence of a block signal system. It's not used in CTC.