Overmod You've got the definitions precisely reversed as notated: Maximum speed for passenger is denominated at 59mph because the rule is "60mph or greater" and the unit of measurement is quantized in whole mph. The limit for any signal system that does not contain explicit ATS ls likewise "80mph or above" (and has been by statute since the early 1920s, purposely confirmed and left unchanged by the ICC Order of 1947). I know all this is what you meant, but it's not what your sentence said.
You've got the definitions precisely reversed as notated:
Maximum speed for passenger is denominated at 59mph because the rule is "60mph or greater" and the unit of measurement is quantized in whole mph. The limit for any signal system that does not contain explicit ATS ls likewise "80mph or above" (and has been by statute since the early 1920s, purposely confirmed and left unchanged by the ICC Order of 1947).
I know all this is what you meant, but it's not what your sentence said.
"On and after January 17, 2012, where a passenger train is permitted to operate at a speed of 60 or more miles per hour, or a freight train is permitted to operate at a speed of 50 or more miles per hour, a block signal system complying with the provisions of this part [ed 49 CR Part 236] shall be installed unless an FRA approved PTC system meeting the requirements of this part for the subject speed and other operating conditions is installed."
I recognize that, as a practical matter, a limit of "60 or more miles per hour" translates to "greater than 59 MPH" and "50 or more miles per hour," translates to "greater than 49 MPH". But that's not what the rule says.
rdamon, thanks , article was a good read.
Northtowne
Speed can also be limited by existing crossing warning circuits. Go too fast and the lights, bell, etc. will not be operating for the mandatory minimum period before the train occupies the crossing. Perhaps more of an issue with older installations that depend entirely on insulated joints and basic DC track circuits.
John
cv_acr Track conditions and also signalling are a factor. I understand there are legal maximums for dark [non-signalled] track.
Track conditions and also signalling are a factor.
I understand there are legal maximums for dark [non-signalled] track.
mudchickenA well trained trackman with a sharp eye and institutional memory is priceless.
Job qualifications for section foreman, back in the day...
Larry Resident Microferroequinologist (at least at my house) Everyone goes home; Safety begins with you My Opinion. Standard Disclaimers Apply. No Expiration Date Come ride the rails with me! There's one thing about humility - the moment you think you've got it, you've lost it...
A good trackman can generally compensate for what goes on when the loading isn't there (thus the mudhole comment and watching the give-and-take in the ballast section.)
You can't have a geometry car on speed-dial for inspections on short notice and shortlines often can't afford them at all (except for the occassional visit by FRA T-2 etc.)....Many of the geometry cars are ballasted extra heavy and some of the off-the-shelf self propelled cars are not heavy enough. trying to equip a truck with measurement gear is just throwing money away - the people that ordered them did NOT understand what they were doing. Clearly did not talk to the AREMA tribe that writes the chapter on g-car basics and suggested guidelines. Now with the gage resistance programs out there, only a few have the funds to invest in the technology. (The pioneer FRA car T-100 started as an oddball SP-SD45X and is super heavy.)
A well trained trackman with a sharp eye and institutional memory is priceless.
mudchicken People forget that those FRA rules are interpretted to mean what the track does under load. (Part of why the track tribe is so nervous about mudholes)
People forget that those FRA rules are interpretted to mean what the track does under load. (Part of why the track tribe is so nervous about mudholes)
I assume this pretty much means that measurements need to be made with a track geometry car. I can see why mudholes would keep the track tribe awake at nights.
Track Inspector works under the Roadmaster/Track Supervisor. All three have the certification under FRA rules as a responsible party. The operating side, Traimanster up to Superintendent (along with the rules examiner and road foreman) may be the one putting out the timetable, but it is the track side that determines the actual speed in the field in the end. Track Department, Mechanical Department, Operating Department are supposed to all be on the same side, but there are limits (and just a little friction at times.) A superintendent or dispatcher is not going to over-ride a decision placed by those under the Division Engineer, etc.
Know of at least one Chief Engineer who got caught trying to remove an FRA slow order off a geometry car to appease an operating general manager, over the objection of a roadmaster who had not checked out the defect location yet - Instant Code 1!
cv_acr - In the US: 49 freight/60 passenger ... not exactly sure what the Transport Canada rule is for the same thing.
Always cringe when the engineer "cheats" to make up time with the logic that the track used to be good for that in the bad old days.
Chris van der Heide
My Algoma Central Railway Modeling Blog
The flip side of this question is this - how fast do trains need to go in a given section?
The terrain and potential track conditions might permit 100 MPH speeds, but if the railroad only needs 25 MPH, that's what the track will be maintained for.
The maintenance cost required to maintain a give class of track has to be balanced with the operational requirements.
If the railroad needs 100 MPH and the track profile won't support that, you'll end up with line relocations, tunnels, cuts, etc to make such speeds possible.
The New York Central famously relocated both their track and the Mohawk River after the Gulf Curve disaster in Little Falls, NY.
In addition, when the route was chosen the railroads engineering personell would determine the inital maximum speed for each segment based upon curvature and slope, A tight curve and the maximum speed would be less than for a wider curve, etc. to prevent derailments. A steeper decending grade might require a slower speed for the same reason..
The simple answer, once track has been put in service at whatever designated speed, is that the track inspector is the one who "owns" what the speed will be. By FRA regulation they are the only ones who have the authority and responsibility to determine how fast the trains can go. This is based on what they find on their trips over the line. They are required to take action based on the conditions they find, BEFORE THE NEXT TRAIN. See 49CFR213 for the specifics.
On the non-regulatory side, there is AREMA, which meets regularly. Again, Mudchicken is the resident expert.
It's not hard to imagine the volumes likely dedicated to exactly what the standards are for each class of track. How much vertical and horizontal variation is allowed, curvature as mentioned, weight of rail, jointed vs welded, and any of a host of other variables.
What is sometimes hard to comprehend is how much labor and know-how it took to maintain jointed rail capable of carrying trains at speeds of 100 MPH before the advent of the mechanized and computer controlled equipment of today.
Good article
https://trn.trains.com/railroads/abcs-of-railroading/2006/05/track-classifications
NorthtowneThis probably been on here before, have to say again I have been away for a good while. Was wondering about the process of setting track speed limits, don't mean the obvious such as curves, bridges, city limits. etc., or special trains, but ordinary main line runs of track between sidings and yards. What do they look at and which department or departments rule on this and how high up the ladder does it go to be final? Northtowne
Was wondering about the process of setting track speed limits, don't mean the obvious such as curves, bridges, city limits. etc., or special trains, but ordinary main line runs of track between sidings and yards. What do they look at and which department or departments rule on this and how high up the ladder does it go to be final?
The owner sets the desired speed for every line that they own. They do this by building and maintaining their tracks to the standards set by the FRA for the various classes of track. If they want 10 MPH, they maintain the track to the level of EXEMPT track - the deteriorated ties with minimal spike holding power and the number of 'wide' guage situations as well as deficienty cross level conditions - ROCK & ROLL. If they want higher speeds they maintain, surface, align the track to the higher standards required for each class of track. The degree of curvature may impose slower speeds than exist on trangent track on the same line.
I am not any kind of expert on track requirements - 'mudchicken' is.
Never too old to have a happy childhood!
This probably been on here before, have to say again I have been away for a good while.
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