Calling Coal Dragger

[26 Inf]

A guy I know asked me if I believed the earth was round or flat. Being clever I answered neither, it is a sphere.

His evidence was that rail track rails aren't arched - I hope he was just being a smartass.

Anyways, that got me to thinking, how do the railroads start a grade - is it just a minor deflection at each joint or something else?

What about continuous rail?

Thanks!

[SomeOtherGuy]

If you want to be pedantic and difficult, the Earth is actually an oblate spheroid.

https://gisgeography.com/ellipsoid-o...pheroid-earth/

Not that I would ever be difficult.

Not Coal Dragger but the acceptable slopes for railroad tracks are very minor, no more than a few %, and steel track is more flexible than you might think in the lengths they use. I suspect the joints are just standard 90/90 degree joints and the flexibility of the track accommodates the minor slope. Guess I'll find out if I'm right as others post.

[Coal Dragger]

A guy I know asked me if I believed the earth was round or flat. Being clever I answered neither, it is a sphere.

His evidence was that rail track rails aren't arched - I hope he was just being a smartass.

Anyways, that got me to thinking, how do the railroads start a grade - is it just a minor deflection at each joint or something else?

What about continuous rail?

Thanks!

The rail is actually quite flexible, the rail will deflect when locomotives and cars pass over, and that deflection takes place in the strongest most rigid cross section of the rail (vertical), the higher the speed or tonnage (or both) the more the rail will deflect under the wheels passing over. You can watch it in real time.

So with that understanding it should come as no surprise that the horizontal cross section is even more flexible, easily conforming to the curves typically in place on most any main line, siding, yard, or industrial tracks you can find. As for grades anything much over 1% is pretty much considered mountain grade, while not that steep by automobile standards it’s plenty steep when you’re operating at less than 1hp/ton. Again the elevation changes even in undulating terrain are never severe enough to not be easily accommodated by the flexibility of the rail.

Also keep in mind ribbon rail (continuous rail) comes off in 1/4 mile long sections, they are usually laid out months to a year in advance to “season” and let the steel acclimate to the temperature changes in the area it will be installed. They want it to contract, and expand for a few months at a minimum so it is stress relieved for the area. So they pull it off the specialized unit train and lay it on the right of way next to the tracks, on the ballast. Not being secured to any ties they conform to the larger contours of the ground like a noodle.

This is a long winded way to explain to you that your friend is correct that the rail is not made with an arch in it, but incorrect in his reasoning because the rail is not rigid enough to stay perfectly strait without support underneath it that is also perfectly strait and level. The rail bends, by design. Your friend is not good at critical thinking, or logic.

[26 Inf]

Your friend is not good at critical thinking, or logic.

Thanks for that explanation.

I've actually been on the locomotive simulator that, I believe, BNSF has at Olathe/Overland Park, Kansas.

Quite an experience to watch the engineer keep the train dead on speed as the train went up and down the steepest grades on the line with the simulator jarring as the train following bumped into slack on the downgrade and took out slack on the upgrade.

My use-of-force simulators paled by comparison.

My acquaintance, we aren't to friend status yet, was just being obtuse, he's actually very bright, retired LAFD and DSS Farsi translator.

[Coal Dragger]

Ah arguing for arguments sake. Sounds like my kind of a-hole!

[AKDoug]

I'll tell you that the most difficult class I took when I was still training to be a land surveyor was Geodetic Computations. Not only is the world an oblate spheroid, it also has spots that are higher and lower than the average that end up being anomalies in the WGS84 datum for navigation.

[Outlander Systems]

NAD83 (2011) masterrace.

I'll tell you that the most difficult class I took when I was still training to be a land surveyor was Geodetic Computations. Not only is the world an oblate spheroid, it also has spots that are higher and lower than the average that end up being anomalies in the WGS84 datum for navigation.

[AKDoug]

NAD83 (2011) masterrace.

Not in my wheelhouse anymore. I found that I made more money in my current business using different math

[1_click_off]

Is mainline rail a standard rating throughout the country? I want to say 110 or 115lbs? A place I worked at had 90lbs from what I remember. Was told this is the weight over a 3’ span? Maintenance said they were ok with every third cross tie being good. Man did we have a lot of derailments until they reworked the yard. One year we needed to put loads in the empty yard. That was a disaster. Got a lot of new rail and ties that year!

Was also told most derailments happen 14-19mph because that match’s the natural fq of the cars swaying with the typical splice lengths.

Have some tribal learning for operating an engine, but that is about all. That was 20 years ago. I still remember opening up the cabinet and throwing that knife switch to juice it up for a start. Anyone know if the above tidbits are close to accurate?

[jpmuscle]

NAD83 (2011) masterrace.

NERD

Somewhat related but Horseshoe Curve in Altoona, PA is a pretty cool engineering structure to behold.

https://en.m.wikipedia.org/wiki/Hors...(Pennsylvania)

I’m trying to the pics I took when I was there last.


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