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Vince (61 posts)
Jan-07-02, 00:55 AM (EST) "Route Editor Object Window Elevation question" A few questions on the route editor.
In the route editor Object Window there is a box labled "Elev". This display changes when I elevate or depress a track or road section.
I suspect this is in degrees but does anyone know for sure?
If it is degrees then;
The question I have is: How do I translate degrees elevation into percent grade? Or visa versa?
For example;
For a 1.5 percent grade, what is the elevation in degrees?
Or for a 1.5 degree grade, what percent grade is this? Is there a formula to calculate both ways?

Thanks in advance.Vince Cockeram
Las Vegas
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Table of Contents

Subject Author Message Date ID RE: Route Editor Object Window Elev... smolds Jan-07-02 1 RE: Route Editor Object Window Elev... akochan Jan-07-02 2 RE: Route Editor Object Window Elev... ATSF Jan-07-02 3 RE: Route Editor Object Window Elev... davidbeach Jan-07-02 4 RE: Route Editor Object Window Elev... smolds Jan-07-02 5 RE: Route Editor Object Window Elev... davidbeach Jan-08-02 6 RE: Route Editor Object Window Elev... JimStrenk Jan-09-02 7 RE: Route Editor Object Window Elev... smolds Jan-09-02 8 RE: Route Editor Object Window Elev... davidbeach Jan-09-02 9 RE: Route Editor Object Window Elev... Vince Jan-10-02 10 RE: Route Editor Object Window Elev... JohnCS Jan-10-02 11 RE: Route Editor Object Window Elev... Vince Jan-11-02 12 RE: Route Editor Object Window Elev... smolds Jan-11-02 13 RE: Route Editor Object Window Elev... Vince Jan-11-02 14

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smolds (38 posts)
Jan-07-02, 03:43 AM (EST) 1. "RE: Route Editor Object Window Elevation question" The percentage of a grade is based on 45 degrees being a 100% grade.The equation is Percent = Degree / 45, or Degree = Percent * 45.Therefore, a 30 degree slope is 66.667% (2/3), and a 3% is found by the equation deg = 45 * 0.03 = 1.35 Remember that you have to approach the maximum slope in small ingrements, to do it all at once would cause the train to jump.Stephen Remove | Alert Edit | Reply | Reply With Quote | Top
akochan (347 posts)
Jan-07-02, 08:53 AM (EST) 2. "RE: Route Editor Object Window Elevation question" Sometime ago somebody posted a handy chart that listed the grades already calculated too. I'm sure a search would bring it up. You might have to go back into archived threads though to find it. I believe it uses that same forumla Stephen posted.-Andy
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ATSF (106 posts)
Jan-07-02, 02:46 PM (EST) 3. "RE: Route Editor Object Window Elevation question" Both the grades and curves are expressed in radians.
1 degree radian = 2 * pi / 360 or 0.0174532
Grades
3.5 grade = .035 / 0.0174532 or 2.005 radians the value you would plug into the RE.
Curves
Angle or delta value 30 degree 30 minute curve
30.5 * 0.0174532 or .532 radians the value you would plug into the RE.
90 degrees a right angle 90 * 0.0174532 = 1.57 the max value you can enter in the RE.Radius of curves is calulated by using 1746 meters for 1 degree curve3 degree curve 1746 / 3 = 582 meter radius.
Hope this helps.
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davidbeach (85 posts)
Jan-07-02, 03:51 PM (EST) 4. "RE: Route Editor Object Window Elevation question" Sorry, but that isn't quite correct.The elevation value is slope in degrees (there is no consistancy anywhere in the math of the program). To convert from per cent grade to slope in degrees -> tan(grade/100), to convert from slope in degrees to per cent grade -> atan(slope)*100. Tan and atan are the tangent and arctangent trig functions, available on any scientific calculator or spreadsheet program (although the function names may vary slightly).The curves are expressed with a radius in meters and an included angle in radians. 360 degrees = 2 pi radians. Again any scientific calculator or spreadsheet program should have degree to radian and radian to degree conversions.Standard american railroad civil engineering practice is to define curves using two angles, a curve would be given a degree of curvature and an included angle. The included angle might be referred to as the total angle or the delta angle. The angle of curvature is the included angle for a 100 foot chord. This is converted to radius (in feet) by the formula 50/sin(1/2 theta) where theta is the degree of curvature. To get the radius directly in meters, use 15.24/sin(1/2 theta). Sin is the sine trig function, again available on a scientific calculator or spreadsheet program.Using a formula such as 1746/curvature works as a reasonable approximation for curves with low curvature, but falls apart for sharper curves, although perhaps not enough to matter in this simulation.David Beach Remove | Alert Edit | Reply | Reply With Quote | Top
smolds (38 posts)
Jan-07-02, 04:42 PM (EST) 5. "RE: Route Editor Object Window Elevation question" I did a search before submitting the reply, nothing came up. Used something like "curve calculating spherical spiral" - maybe a bit more than was needed. BTW, are horizontal RR curves figured in the same way?Stephen
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davidbeach (85 posts)
Jan-08-02, 03:36 PM (EST) 6. "RE: Route Editor Object Window Elevation question" The slopes discussed were constant grade slopes. The curves discussed were constant curvature horizontal curves. Vertical curves and easements of horizontal curves add a fair bit of complexity and can not be modeled in MSTS except by breaking them up. A vertical curve would have to be made from multiple segments of constant grade and the easement of a horizontal curve would have to be made with multiple sections of constant curvature, but with a decreasing (or increasing as the case may be) radius.David Beach Remove | Alert Edit | Reply | Reply With Quote | Top
JimStrenk (157 posts)
Jan-09-02, 01:21 AM (EST) 7. "RE: Route Editor Object Window Elevation question" Would it be possible to create track sections that are straight but curve upwards or downwards, rather than just "flat" track sections?It would seem at this moment that SHORT track sections should be used for constantly changing terrain, using LONG sections when the terrain is either flat or doesn't change slope very much. This would allow you to follow the terrain more closely. Is my assumption correct? Remove | Alert Edit | Reply | Reply With Quote | Top
smolds (38 posts)
Jan-09-02, 02:10 AM (EST) 8. "RE: Route Editor Object Window Elevation question" Jim,These might be usefull - but to use with caution. If you can traverse a section using straight track with shallow cuts and fills - avoiding a rollercoaster ride. Remove | Alert Edit | Reply | Reply With Quote | Top
davidbeach (85 posts)
Jan-09-02, 08:41 PM (EST) 9. "RE: Route Editor Object Window Elevation question" Very short answer - No. The program does not support vertical curves, nor does it support horizontal curves other than constant curvature (constant radius). Each piece of track will have a constant grade (flat being a special case of constant grade) and may have a radius in the horizontal.Mainline tracks generally take out the roll of the terrain through cuts and fills. Light weight/low density branch line, and in particular those built by electric railray companies, on the other hand just scraped off the surface vegitation and follow the lay of the land up and down, use lots of short segments.David Beach Remove | Alert Edit | Reply | Reply With Quote | Top
Vince (61 posts)
Jan-10-02, 09:54 PM (EST) 10. "RE: Route Editor Object Window Elevation question" >The percentage of a grade is based on 45 degrees being a 100% >grade.The equation is
>Percent = Degree/ 45, or Degree = Percent * 45.
>
>Therefore, a 30 degree slope is 66.667% (2/3), and a 3% is found >by the equation deg = 45 * 0.03= 1.35
>
>Remember that you have to approach the maximum slope in small
>ingrements, to do it all at once would cause the train to jump.
>
>Stephen Stephen, I think this may be in error. A 100% grade would be 89 degrees (or maybe 90 degrees?) Therefore 45 degree is 50%, 22.5 degrees is 25%, 11.2 degrees is 12.5%, 5.6 degrees is 6.25% and so on down. So when you get down to around 3 degrees and lower
the percent grade gets real close to the slope in degrees, close enough so when laying out gradients we can use the figure in the elevation window as a percent grade figure. According to Al Krug's website a heavy mountain grade is 2.8 percent. So for this grade I would use an elevation of about 1.8 - 2.0 in the route editor window, though I am trying to keep the grades below 2%.

I am currently trying this out on the Innsbruck Route, laying a parallel route near the northern edge of the tiles for that route
and I will see if a steamer can make these grades I layed out.Thanks for your input,
Vince Cockeram
Las Vegas Remove | Alert Edit | Reply | Reply With Quote | Top
JohnCS (229 posts)
Jan-10-02, 11:29 PM (EST) 11. "RE: Route Editor Object Window Elevation question" Stephen is correct.% grade = rise/run Remove | Alert Edit | Reply | Reply With Quote | Top
Vince (61 posts)
Jan-11-02, 02:38 AM (EST) 12. "RE: Route Editor Object Window Elevation question" >Stephen is correct.
>
>% grade = rise/runJohn,
Let me understand this. You say a 100 foot rise divided by a 100 foot run is 1 percent!!?? How is that is correct? What am I missing here? Actually all I'm trying to find out here is what relation do the numbers in the elev. display in the route editor have to percent grade? IOW, if I elevate a section of track and the number in the window sez 1.600, what percent grade is this?Vince Cockeram
Las Vegas Remove | Alert Edit | Reply | Reply With Quote | Top
smolds (38 posts)
Jan-11-02, 02:56 AM (EST) 13. "RE: Route Editor Object Window Elevation question" "Let me understand this. You say a 100 foot rise divided by a 100 foot run is 1 percent!!?? How is that is correct? What am I missing here?"100/100 = 1, which is then multiplied by 100 to get 100%.A 50 foot rise and a 100 foot run is 50/100 = 0.5 * 100 = 50%. Remove | Alert Edit | Reply | Reply With Quote | Top
Vince (61 posts)
Jan-11-02, 06:03 PM (EST) 14. "RE: Route Editor Object Window Elevation question" LAST EDITED ON Jan-11-02 AT 06:15 PM (EST)>% grade = rise/run>
>100/100 = 1, which is then
>multiplied by 100 to get 100%.
^^^^^^^^^^^^^^^^^
>A 50 foot rise and a
>100 foot run is 50/100
>= 0.5 * 100 = 50%.Got it! Those factors get me every time. So now what do the numbers displayed in the Route Editor have in relation to a grade percent?Vince Remove | Alert Edit | Reply | Reply With Quote | Top

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