Curves in surveyor

I like using: "FT 15 Degree 250m Radius" fixed track ... and using the "Hold Shift" keyboard key (alternating with "Don't Hold Shift" key) ... I lay track right on top of the FT Track, using it as a spline point location template. Then I slide the FT Track out from under my track, and place it on my painters pallet of usefull tools and experimental assets.
 
When I have needed a fixed radius track (not often as real railways/railroads use transition curves) I use the correct radius updating fixed track, rotating/joining as many lengths as necessary, and add to it the spline track of my choice. It updates and of course the spline can then be deleted if not needed. However, not easy for very tight radius curves on tram track and I haven't yet succeeded in making curved fixed track.

Another option for more prototypical track is to lay the fixed track etc. as suggested finishing with a short length of straight at each end, then delete the curves and replace with one length of spline.

Ray
 
The sad answer is no. Templates and fixed track are made at specific radii. If you want something different you have to eyeball it - well there's always the ruler(s) - interpolating or extrapolating between/from templates - you want a specific angle - there used to be a couple of big 3rd party protractors around.

Surveyor is a bit of a misnomer - there's not much built into it you can use to survey a route. It's best suited for artistic rather than engineered work. I convert cad drawings of the route directly to trk files which provides really great accuracy except Auran keeps changing the map file formats on me. So I still work in TRS6 and import the routes into the newer versions if I ever need to.

Railroards are surveyed using tangent - straight lines and circular curves. Transition curves or spirals are used as lead ins and outs of the circular arc sections of the curve. Lengths of the transitions are often set to match the transition requirements of the superelevation in the curve. The track spline used in Trainz is a cubic spline but doesn't match transition curves used by railroads or form exactly circular arcs. Trying to force them into circular arcs has it own set of problems. The spline points must be set at equal intervals (30 deg or less) along the curve and the end tangent at each end must be accurately set using straightened sections of track. The angles have to accurately set. Something not easily done. Sometimes you can get it to look pretty good but the curvature still varies along the curve. Running trains round them usually shows some wobbles at spline points. Using fewer spline points can actually reduce the irregularities but results in larger variation in the radius along the length of the curve. Getting accurately designed track work into Trainz was the main reason I started doing my track work using a cad program, converting them and bypassing surveyor.

Bob Pearson
 
Last edited:
Back
Top