A local bike path has a good view of part of the BNSF line through town. Looking down at a curve, it’s really obvious that the rails aren’t always parallel. How far out of gauge can the rails be before there’s a problem?
Thanks to Chris / CopCarSS for my avatar.
That's a Mudchicken question...
I suspect there's a certain amount of "it depends," but it's not much at any rate.
I did find this:
The US standard railroad gauge is 4 feet, 8.5 inches (Gauge means width between the two rails). The U.S. federal safety standards allow the standard gauge to vary from 4 ft 8 in (1,420 mm) to 4 ft 9 1⁄2 in (1,460 mm) for operation up to 60 mph (97 km/h).
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...
Murphy Siding A local bike path has a good view of part of the BNSF line through town. Looking down at a curve, it’s really obvious that the rails aren’t always parallel. How far out of gauge can the rails be before there’s a problem?
The requirements for gauge are pretty simple. Per 49 CFR 213.53, minimum gauge is always 56", maximum gauge is 58" for Class 1 track, 57.75" for Class 2 and 3, and 57.5" for Class 4 and 5.
Of course, any variation in the superelevation of the curve also results in the rails not being parallel.
Sometimes looks can be deceiving - you can see that SOMETHING is going on at a spot, but at first glance it might be hard to tell what that something is. We once designed a very short 5' curve with long spirals into what had previously been a tangent track. Frankly that's pushing the limits of what you can construct with ballasted track, or at least what a typical tamper operator working on a freight railroad can do. So I'm not sure what we really wound up with. But when you look at it, it doesn't look like a curve at all, it looks like a dip.
Dan
A person's eyes are the worst judge of measurments on railroad properties - trying to judge line or gauge by sight without the aid of specific measuring tools is a exercise in futility.
When riding a locomotive - many times you can only tell if you are going up or down a 'grade' is by watching the operation of the load meter - your eyes cannot discern small changes in grade. You 'may' think visually that you are going up a grade when you are infact descending a grade.
Never too old to have a happy childhood!
Murph: I'll look it up, but you are looking at a function that varies by class of track.
(really "bad day at the office" today.*.. I'm spent.)...The wheels fall-in automatically at 61", but you are somwhere between excepted track and Cls 5 track which nominally puts you between 55 1/2" and 60"....What Balt and some of the others are hinting at is why trackmen will bend over and look between their legs in order to get rid of parallAx and why the brain tries to compensate - sometimes with bad results. The heat over there just is making it worse.
(*) started off shutting a project down until a certain civil engineer got right of entry and a flagman arranged, made him go cut bugetary corners somewhere other than on the railroad R/W that he had not addressed properly. I think I melted the phone and the wirelines this morning resulting in a mushroom cloud in central Illinois.
I sometimes joke about the old section foremen with "calibrated eyeballs" who were able to keep their track up to amazing standards without tools.
I suspect it's as much an art as it is a skill.
Years ago I was riding in a hi-rail with a roadmaster on BC Rail and when we came to a certain spot he commented "I think the gauge is wide here" so we got out and measured it with a gauge. Sure enough it was maybe 3/4" wider than standard. I asked him how he could judge something like that just by eye. He doesn't look at the distance between the rails, but instead observes the position of the shiny wear area on the top of the rails.
Smokey wood stoverYears ago I was riding in a hi-rail with a roadmaster on BC Rail and when we came to a certain spot he commented "I think the gauge is wide here" so we got out and measured it with a gauge. Sure enough it was maybe 3/4" wider than standard. I asked him how he could judge something like that just by eye. He doesn't look at the distance between the rails, but instead observes the position of the shiny wear area on the top of the rails.
There are individuals whose eyes can be freakishly accurate when it comes to judging measurements - they are few and far between, but they do exist.
A friend of mine in racing has such skills when it comes to alignment settings for race cars. If he looks at a car and says it has a 1/16 inch toe in - and you put the measuring tape on it and it is 1/16 inch toe in.
Smokey wood stover Years ago I was riding in a hi-rail with a roadmaster on BC Rail and when we came to a certain spot he commented "I think the gauge is wide here" so we got out and measured it with a gauge. Sure enough it was maybe 3/4" wider than standard. I asked him how he could judge something like that just by eye. He doesn't look at the distance between the rails, but instead observes the position of the shiny wear area on the top of the rails.
I'd be very surprised if anyone could see 3/4" wide gauge through a rail wear pattern. 3/4" wide gauge is within tolerance for speeds up to 220 MPH.
But in a sufficiently sharp curve with sufficiently wide gauge, it is actually relatively easy to see a particular tell-tale wear pattern. Even I can see it clearly if I'm looking for it. (For instance: if the geometry car reports a defect and I have to find the particular spot in the field. Not part of my present-day job but it once was.)
Here's what happens. Worn wheels develop a "false flange" on the field side of the wheel tread. (Rather than trying to explain exactly what this means, I refer you to Page 3 of this link.) With normal track gauge the false flange does not contact the rail at all, or if it does so it happens near the field-side corner of the head of the rail. But if you have wide gauge in a reasonably sharp curve, the false flange will actually wind up positoned on top of the rail head on the low rail, and the whole wheel load will be riding on that sharp, narrow area. The high contact pressures that result cause highly accelerated rail wear underneath.
In other words, the worn wheels wear a groove into the rail head on the low rail as they track through a curve with wide enough gauge.
Once you see these marks it's very easy to verify that you have a problem by watching a train pass over. At the spot where you see the grooves in the railhead, you usually will see half of the head of the low rail peaking out from underneath the wheels. (Unless, of course, someone has already fixed the gauge problem since the marks were made.)
The cases I remember seeing these false flange grooves were all on 10 MPH track, where gauge was more than 58" (i.e. more than 1.5" wide) and therefore defective even for 10 MPH.
I gotta admit, I have a lot of quirks about me, but only a few super-powers. One of my super-powers is that I can tell if lines are parallel. I attribute that to drawing and reading blueprints for 40 years. When I look at the curve in question, I can see that the outside radius is consistent. The inside radius is not. It dips in and out a little bit at two spots. That's where I see that the rails aren't always parallel. One of my other super-powers is that I can hear really low pitch sounds that others apparently can't- the way dogs can hear high pitched sounds. I can hear a train coming about 5-10 minutes before I hear a horn. So I got that goin' for me, which is nice. I can't hear very well in other ranges, but I attribute that to being married for 32 years. And so it goes.
I watch trains on the Ashland Virtual Railfan channel. While the gauge might be normal, these trains bounce up and down a scary amount. I guess CSX doesn't care, just like they don't seem to care about flat spots on railcars, either.
Murphy's railroad (LS-144 / Sioux City Sub) is 49 MPH/Dark territory (FRA Class 4) that allows up to 1" additional gage width...Slow down 9 MPH and you are allowed 1-1/4" in FRA Class 3.
The track machinery that lines curves focuses on lining one rail, usually the inside low rail (same side as the light beam projector), depending on the equipment used. The other rail just mimics the lined rail and often has little imperfection wobbles in it due to excess or too little rail being pushed along and distributed during the lining operation. In Murphy's case, sounds like the tonnage is hitting the curves at just over equilibrium speed with the lateral forces pushing the wheel flanges up against the outside/high rail. Chief Engineer's staff might contemplate adding 1/2 - 1 inch of elevation in the curves there to lessen the wear if they can get away with it. (lesser evil because they cannot go any faster in dark territory?)
Murphy's railroad (LS-2003 / CantonSub - I suspect ) is 49 MPH/Dark territory (FRA Class 4) that allows up to 1" additional gage width...Slow down 9 MPH and you are allowed 1-1/4" in FRA Class 3.
How's your paralax vision? (may be part exageration in what you're seeing)
Anywhere close to where you unload toothpicks?
aegrotatio I watch trains on the Ashland Virtual Railfan channel. While the gauge might be normal, these trains bounce up and down a scary amount. I guess CSX doesn't care, just like they don't seem to care about flat spots on railcars, either.
That's evident at the diamond at Deshler - there's quite a bounce there. One would think that such a bounce would stress the plant and that they'd want it out, but they don't seem to care.
They did do some work on it a while back, but you can still see a very definitive bounce, especially on the westbounds.
tree68 aegrotatio I watch trains on the Ashland Virtual Railfan channel. While the gauge might be normal, these trains bounce up and down a scary amount. I guess CSX doesn't care, just like they don't seem to care about flat spots on railcars, either. That's evident at the diamond at Deshler - there's quite a bounce there. One would think that such a bounce would stress the plant and that they'd want it out, but they don't seem to care. They did do some work on it a while back, but you can still see a very definitive bounce, especially on the westbounds.
CSX has two Geometry Trains that operate over the system on a continuing basis. I believe the intent is to have all the Main Lines tested once each quarter. There are additional hi-rail testing vehicles that traverse the system. Additionally the FRA has test cars and trains that operate over CSX and all other carriers. CSX also hires specialist, such as Sperry, to perform their specialized testing to the physical plant.
What actions CSX takes upon the data that is mined from the testing is up to the Engineering Department and is beyond my expertise.
I do know that the various testing units will issue Slow Orders for specific locations based upon the real time views of their testing results. Testing equipment operating on a Dispatcher's territory can keep the Dispatcher busy all trick.
(and you have the accelerometer equipped Amthrax ride quality cars with the world famous "Empty Beer Can On The Dashboard Ride Quality Test")
I'm sure the roadmaster would like to do more, but he neither has the resources/people nor the budget to do so. So IF the issue does not take the track outside his expected FRA Class, it gets left alone. The track forces, what's left of them, are still attacking the bigger headaches you are not seeing in the continuing track maintenance whack-a-mole game.
The soft subgrade and mudholes like to move around and be unpredictable ... and the swamps that surround the lakes that the railroads built around in the 1850's from Cleveland to Chicago have never gone away. Tile field drainage helped, but the soils still are not that great.
mudchicken ...and the swamps...
Alas, Deshler is in the "Great Black Swamp" (https://en.wikipedia.org/wiki/Great_Black_Swamp), where drainage is always a problem. That said, I've never noticed pumping there when I've visited.
As I said, I'd think CSX would want to deal with a spot that makes the locomotives jump like they do, especially at the 35 MPH permitted over the diamond. I have heard, though, that the crews don't notice. Sometimes speed can make a rough spot seem less rough as the suspension does its job.
tree68 mudchicken ...and the swamps... Alas, Deshler is in the "Great Black Swamp" (https://en.wikipedia.org/wiki/Great_Black_Swamp), where drainage is always a problem. That said, I've never noticed pumping there when I've visited. As I said, I'd think CSX would want to deal with a spot that makes the locomotives jump like they do, especially at the 35 MPH permitted over the diamond. I have heard, though, that the crews don't notice. Sometimes speed can make a rough spot seem less rough as the suspension does its job.
Recall in the late 90's when CSX was re-multiple tracking from Sherwood, OH to Chicago - a 3rd track was put in in the vicinity of Garrett. When the track was initially put in it sunk - into the swamp. The were a number of passes of industrial strength grouting that were initiated before the track would hold line for any period of time. I believe that that particular area is still being treated with industrial grout on a continuing basis.
Terra Firma is not always firm.
Our community is FREE to join. To participate you must either login or register for an account.