Reading track profiles

[Anonymous]

I have some track profiles and can interpret *some* of the information on it, but some I cannot. Can anyone recommend some sort of reference that would help me to interpret it? There's a *lot* of information packed onto the pages, and I would like to know what some of it is. This info I have is labeled "Track Chart and Alignment Book" and contains all of SP's Oregon Division. Do different railroads use different notations? Would I need to find something SP-specific to read this stuff I have?

[dehusman]

There are unique things to each one.

The worst was trying to figure out an NdeM chart that was drawn by the SCNF from France. Absolutely no rhyme or reason. A subdivision would enter one side of one town at 500 ft elevation and exit the other side at 1000 ft elevation. ????

What has you stumped?

Dave H.

[Anonymous]

there is a lot of information on condensed profile. i am familiar with the milwaukee road condensed profiles and the chicago and north western condensed track charts and i would assume the sp and something similar.

the term "profile" means a view of the track from the side showing the elevations of the line and the condensed profile shows that but it shows much more than that. it also has a straight line diagram of the main line which shows curves by showing the beginning and end of the curves and the sharpness of the curves. it shows sidings, industry tracks, stations, bridges, culverts, highway crossings and crossings of other railroads. it may show the weight and year of manufacture of the rail and ballast.

let me know if you have any specific quesitons.

bye. Larry

[Anonymous]

Well, it's gonna be hard to describe until I get a page scanned so's you can see what I'm talking about. However, I'll try (this is only one of the questions). One of the lines that spans the pages (I'll call it a 'base line') has small horizontal blocks on either side of it, with another shorter block on top or below it.. Sort of like a short brick on top of a longer one. There are similar 'bricks' reversed below the center line. There is a degree measurement, such as 3.00' (I use the dot 'cause I don't think there's a 'degree' symbol) above the center short 'brick', and text such as T-150' or T-90' labeling the ends of the longer 'brick' that stick out past the short brick on top. The T-numbers appear to have the same value on either side of the center 'brick'. On one of the other pages, the base line has the text NO CURVES. I assume this base line describes the curves, so the 3.00' is a three degree curve to the right or left (above or below the base line), and the T-numbers represent the easement. So, does T-150' mean there's 150 feet of easement into and out of the curve? Each 'set' of 'paired' bricks also has a number, which I take to mean curve number, since they're numbered sequentially.
Another question: It appears that the same point has two different milepost values. This seems to occur when one branch line meets another. Where they meet, two vertical lines are drawn with the word EQUATION between them. A sample pair of values are 344.167 and 344.338. I'm guessing that the distances are descrepancies due to measurements from different starting points?

Thanks,
Chris

[Anonymous]

I cannot be sure what the sp charts indicate. the figures at the ends of the curves may very well be the length of the spirals that provide a transition from straight track to curve. The sprial is where the superelevation, or tipping of the track, goes from zero on the straight track to the maximum in the curve. The other numbers sound like the degree of curvature.

Engineers use equations to equate measurements from different starting points as you suspect.

Larry

[BillParksAV]

If you go to http://spcascades.railfan.net/profile.html, you'll find a good explanation of SP's system. This may be the same format you have. In any event, it includes the profile between Eugene and Klamath Falls. You can compare those to your book.