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Re: SP gear ratios
Author: OldPoleBurner
Date: 12-17-2010 - 17:49
This thread has been an interesting exchange for sure.
> The 79 mph limit makes sense. The ICC/STB/CFR limits passenger trains in signalled
> territory to 79 mph unless some sort of CCS or ATS is functioning. I know SP had ATS
> for a while on Donner, but I'm not sure there are too many places you would want to
> do 79 mph without a parachute.
There were a great many places around the country, that had some sort of ATS, ATC, CCS, or whatever, and even mechanical trip stops of various sorts; most of it being just the "Intermittent Inductive Train Stop" (ATS). In some cases the railroads put it in because of marketing reasons, or because they were the ones that invented it (Pennsy) and thought the invention would get them one up on the competition. But in other cases, it was because of local or state mandates None of these systems were installed because of any mandate in relation to speed.
Though the ATS was by far the most prevalent, the "Continuous Inductive" type (ATC/ATP) was much better. It all along, could have been as effective at controlling passenger trains, as is hoped for with PTC/PTS. In fact, one such existing installation has already been certified as fully compliant with PTS requirements. To get that certification from the Feds, "forstalling" must be used only at restricted speed, and every cab must be equipped with "Continuous Braking Supervision", which enforces the cab signal aspect by continuously enforcing a predetermined braking curve to the next block limit or signal. In this particular installation, wayside signals are not used except at "Control points".
However, all this blew-to-he!! when the Feds (ICC) codified the 79mph requirement in the early/mid 50s. It pretty much preempted and negated any other mandate railroads may have had. Thus many railroads (SP included) began removing most of the ATS on any line with a top speed 79 or less. Along with that also came the lowering of almost all top speeds to the 79 non-ATS limit - or less. ATS is mostly gone now.
Notable exceptions were the ATSF and the Pennsy - Both grand railroads in my view.
But generally, the day of truly high speed American passenger service thus came to an abrupt end. In my view, the ICC / Congress totally screwed up. They should have specifically avoided negating any existing mandates. In fact, to be entirely logical, the ATS/ATC limit should been set somewhere around "medium speed" (already prepared to stop at the next signal).
> Don't worry - when RCU, PTC and Digital brakes are fully implemented there will
> never be another accident (that they won't be able to blame on an employee).
There never was an accident they couldn't blame on employees. It never was necessary that he actually be at fault to get blamed. But the truth is, that the better technology gets at preventing human error, there will be fewer accidents actually caused by those pesky humans.
What some may not understand though, is that even if there are far fewer human caused accidents - there very well could be many more machine cause accidents. What railroad managements, and some politicians in Congress don't seem the get (or don't care about), is that those machine caused accidents will be no less lethal and unpalatable as the human caused ones were.
Therefore, in advancing new technologies that employees will come to absolutely rely on to help them avoid dangerous mistakes; we must make absolutely certain that those pesky new machines (PTS/PTC) are in fact, less prone to hazardous failures than what they are replacing. Otherwise, there WILL BE MORE accidents to blame on somebody - not less.
Now good luck with that!
- given that federal politicians at the behest of well-healed lobbyists for certain railroad vendors - are themselves making the technical decisions, rushing it forward before any true peer review can be completed.
At least - I will be retired before I can be forced to put my name on the safety certification of any such installation. And without the A.R.E.M.A. peer-review and broad consensus of my peers in the field, I ain't gonna sign nothing!
> The 79 mph limit makes sense. The ICC/STB/CFR limits passenger trains in signalled
> territory to 79 mph unless some sort of CCS or ATS is functioning. I know SP had ATS
> for a while on Donner, but I'm not sure there are too many places you would want to
> do 79 mph without a parachute.
There were a great many places around the country, that had some sort of ATS, ATC, CCS, or whatever, and even mechanical trip stops of various sorts; most of it being just the "Intermittent Inductive Train Stop" (ATS). In some cases the railroads put it in because of marketing reasons, or because they were the ones that invented it (Pennsy) and thought the invention would get them one up on the competition. But in other cases, it was because of local or state mandates None of these systems were installed because of any mandate in relation to speed.
Though the ATS was by far the most prevalent, the "Continuous Inductive" type (ATC/ATP) was much better. It all along, could have been as effective at controlling passenger trains, as is hoped for with PTC/PTS. In fact, one such existing installation has already been certified as fully compliant with PTS requirements. To get that certification from the Feds, "forstalling" must be used only at restricted speed, and every cab must be equipped with "Continuous Braking Supervision", which enforces the cab signal aspect by continuously enforcing a predetermined braking curve to the next block limit or signal. In this particular installation, wayside signals are not used except at "Control points".
However, all this blew-to-he!! when the Feds (ICC) codified the 79mph requirement in the early/mid 50s. It pretty much preempted and negated any other mandate railroads may have had. Thus many railroads (SP included) began removing most of the ATS on any line with a top speed 79 or less. Along with that also came the lowering of almost all top speeds to the 79 non-ATS limit - or less. ATS is mostly gone now.
Notable exceptions were the ATSF and the Pennsy - Both grand railroads in my view.
But generally, the day of truly high speed American passenger service thus came to an abrupt end. In my view, the ICC / Congress totally screwed up. They should have specifically avoided negating any existing mandates. In fact, to be entirely logical, the ATS/ATC limit should been set somewhere around "medium speed" (already prepared to stop at the next signal).
> Don't worry - when RCU, PTC and Digital brakes are fully implemented there will
> never be another accident (that they won't be able to blame on an employee).
There never was an accident they couldn't blame on employees. It never was necessary that he actually be at fault to get blamed. But the truth is, that the better technology gets at preventing human error, there will be fewer accidents actually caused by those pesky humans.
What some may not understand though, is that even if there are far fewer human caused accidents - there very well could be many more machine cause accidents. What railroad managements, and some politicians in Congress don't seem the get (or don't care about), is that those machine caused accidents will be no less lethal and unpalatable as the human caused ones were.
Therefore, in advancing new technologies that employees will come to absolutely rely on to help them avoid dangerous mistakes; we must make absolutely certain that those pesky new machines (PTS/PTC) are in fact, less prone to hazardous failures than what they are replacing. Otherwise, there WILL BE MORE accidents to blame on somebody - not less.
Now good luck with that!
- given that federal politicians at the behest of well-healed lobbyists for certain railroad vendors - are themselves making the technical decisions, rushing it forward before any true peer review can be completed.
At least - I will be retired before I can be forced to put my name on the safety certification of any such installation. And without the A.R.E.M.A. peer-review and broad consensus of my peers in the field, I ain't gonna sign nothing!
