View Full Version : Applying a consistant grade (track incline)

December 11th, 2006, 05:59 AM
I am pretty good at surveyor. But I am working too hard!!! How do you lay track and get a consistant grade?!?! As it is I have to get down low (Viewpoint) and eyeball it. Guessing at the grade. And then using the spline smoothing features to get the terraign good enough.

Any help on this?

What does 'spline splitting' do?

December 11th, 2006, 06:59 AM
:cool: Thanks for your query, Tristen,

It depends on a lot of factors....

What railroad are you modding?

It seams like your using DEM routes...great!

The USA standard for mainline grades, is limited to 2.5%. That's a hard grade, that shall require pusher service, or doubling the train over the grade.

Riding out the route in a car, may convince you that the grade is compensated by cutting into the ground.

Using map services like NASA World Wind 1.4, gives the real birds-eye view of the area.

And extreme patience, using Surveyor tools, will produce a route you can be proud of!

And I so hope to run!

December 11th, 2006, 07:28 AM
Hi Tristen

This is how to apply grades to track.
Get a fresh baseboard to work on just for practice. Lay a piece of track from one end to the other. Now add a spline somewhere in the center.
Now click on the advance button in the little window and in the dropdown window type in a grade like 1.5 or so and now click on the apply gradiant icon now click after the the first spline of your track. You will see the track rise now click right after the next spline and the rest of your track will now rise. Now click on the smooth terrain button and your track and see what happens.

That's how it works. Have fun.

December 11th, 2006, 11:03 AM
I have a different approach. I lay a length of straight track from the start of the gradiant to the end, whether it be one baseboard or several and apply the gradient at the end. I then add spline points where i require the line to curve and drag it to the required position.

December 11th, 2006, 11:10 AM
...oh and use the ruler to measure the length of track and work out the percentage of height required so as not to exceed it. Adding curves to the track will of course lessen the gradient.

December 11th, 2006, 03:46 PM
Hi TristenEugene,

I use Escafield's method entirely. It gives a good constant gradient. Even though the finished track has a slightly different gradient from what you originally started with, it is quite small and is changed only because the total length of track has changed. (i.e. the shortest distance between two points is a straight line) To find the difference use the "Get Gradient" tool after you have curved the track. Anyhow the bottom of the gradient and the top of the gradient will still have the same amount of difference in height.


December 11th, 2006, 04:02 PM
I've been laying the track for the EP&SW near Douglas AZ. I have the track chart giving grade, degree of curvature, and elevation at points ("stations"), along the entire route I lay a section of track with the follow terrain turned off so I get a straight or curved track approimateing the correct position then apply the correct garde from one end then adjust the terrain to match the track. Since the track chart gives fills cuts bridges and culverts as well I can match things really well.

I'd reccommend trying to find a track chart for the RR you are building as it gives a huge (more tahn you can use) amount of info about the line. in conjunction with google earth to pin point main locations and the world coordiant marker I can lay track to correct grade and position. THis requires some work with EXCELL and the rulers to get it all accurate. It all depends on how accurate you want to be.

December 11th, 2006, 06:10 PM
I've used TrainzMap. Place the Anchor at one end of the track you wish to apply the gradient to, then turn on the fixed track option. This makes the spline point nodes visible. Note down the distance from the anchor to each spline point by moving the cursor over the point - the distance from the anchor is displayed in bottom right. Return to surveyor. Note down the height of each end of your gradient. The height of each intermediate spline point can then be calculated simply by
Height of intermediate point = Height of lowest point + (Total difference in height x distance from lower end of gradient / Total distance of gradient)
This will give a constant gradient, taking into account of curves.
Hope thats clear!

December 11th, 2006, 10:31 PM
On the DHR we used DEM for the 400ft to 7405ft, 54 mile route. It is a single-track main which made the grading easier. I did the initial tracklaying.

What I essentially did was take each milepost (or in some cases each height indication at MP xx) and subtracted the lower elevation from the higher elevation. This gives you the height difference between two known mileages. Some dividing and you have what you need to set your gradient tool for the grade. Most of the tracklaying was also done using the DEM countryside as a guide. First we had to find the actual route through the mountains. Where maps are scarce, this is very tricky.

As it turns out, the actual DHR runs gradients up to and including just over 18% (yes, I said 18% :eek: ). This is a 2-foot narrowgauge and runs consists of just a single engine and up to three cars. Max speed is just under 20KPH. My avatar is a DHR consist.

Whether you start with the track and make the gradient, or start with the DEM already built, making the track match the terrain is tricky, but it can be done.

December 12th, 2006, 05:13 AM
:cool: Check out these pics...

http://img85.imageshack.us/img85/1410/csx7385eastapproacheshood9.th.jpg (http://img85.imageshack.us/my.php?image=csx7385eastapproacheshood9.jpg)

http://img134.imageshack.us/img134/4349/bnsf5642eastbellevuerpjgz7.th.jpg (http://img134.imageshack.us/my.php?image=bnsf5642eastbellevuerpjgz7.jpg)

http://imageshack.us/img/iss4.png (http://imageshack.us)

December 15th, 2006, 06:22 AM
Outrageously wonderful!!!! Thanks to all!! I am currently using the drop down add grade method. This really helps!!!

I really enjoy the Northbay county theme.

Thanks: Dave, David, Bob, Allen, Nick, Hiballer.


September 17th, 2009, 06:18 PM

I layed a 5280' long ruler across several flat blank baseboards...and stretched a straight track, overhanging each end a little longer that mile long ruler. Next, I added 40' boxcars, until it was as long as the ruler, a one mile long train...I saved the train as "New Consist", and renamed it as: "5280 Foot Train". I started laying 5280' train sections on to each other, and continued until it was 12 sections long...stretching from Galitzin Tunnel to Altoona. So the distance is roughly 12 miles.

If I measure my height at the summit at Galitzin Tunnel (663.98 m), and my base in Altoona (356.01 m)...that's a 307.97 meter rise. So, 307.97 meters works out to be 1007.54 feet...divided by 12 miles, works out to a an 83.69 rise per 100'...or a 0.8369 % gradient (0.84 %).

Of course this really isn't prototypical, as the real grade is much steeper in places, and has hills and dips in the real grade.