Reverse Loops - A Workaround

3DTrains · Post by **3DTrains** » Mon Nov 24, 2003 4:08 pm

I first posted this at t-s.com, and thought some of you might be interested in the following info...

I think I may have stumbled onto a solution for reverse loops, ones that can be built without signals, and yet still allow either path to be taken while in explore mode (my favorite part of this).

It all starts with my old LTV/Erie route, and the problem of the reverse loop at the harbor has bothered me for over two years now. Only recently, while messing with my ScaleRail, did I discover a work-around for the initial problems of loops and how to get a train to take the straight path (to the docks at Taconite Harbor) instead of the diverging route (the wrong way), as usually is the case, and doing all this while in Explore mode.

I discovered that if I built the turnout model normally, but set the parameters in the tsection.dat to fool MSTS to think it was a 3-way automatic turnout, that I could take either (visually normal) path through the turnout, and never worry about the sim sending my train into the dirt. I also discovered that subsequent turnouts within the loop (Taconite Harbor is actually a loop/passing siding combo) can be set to either path, and even be reset should you decide to back your train through the alternate route. This procedure appears to work without issue â€“ save one: while you can create activities to begin inside or outside the loop, you cannot however, set take the diverging path through the first switch. No problem for me in this case, as the whole point was to go â€œstraightâ€

jjules · Post by **jjules** » Mon Nov 24, 2003 4:28 pm

Looks impressive. I'll have to bear this in mind...

tinsley · Post by **tinsley** » Mon Nov 24, 2003 5:38 pm

Thanks for that.....there seems to be big potential in that.

3DTrains · Post by **3DTrains** » Mon Nov 24, 2003 9:42 pm

As I posted at t-s.com, everything appears to be working fine. I created a simple activity to bring a string of 100 cars (with three GP9's) down from Cramer to the docks, but the auto switches didn't throw (drat).

However, after reducing the number of cars by 10, so that the entire train fit between the first auto switch and the first normal turnout (just past the dock), all was well again. I suspect MSTS gets really confused if your train is fouling the main somewhere along the logical path (with no signals to tell the sim otherwise).

More testing and playing.

saddletank · Post by **saddletank** » Mon Nov 24, 2003 11:20 pm

Why does the sim want to take the curving path on a turnout that forms part of a reversing loop? It usually defaults to the straight path.

Your scale track is looking very nice. Will you be adding check rails, wing rails and tie bars etc?

3DTrains · Post by **3DTrains** » Tue Nov 25, 2003 2:28 am

Why does the sim want to take the curving path on a turnout that forms part of a reversing loop? It usually defaults to the straight path.

I don't know for sure, but I believe (without signals) the sim will set the points to the path through the points last calculated, but I noticed too that the MainRoute line in the tsection gets stuffed, and might be why deverging manual turnouts have no effect. Not exactly sure why MSTS allows me to use the 3-way auto switches. All I know is that they appear to be working.

Your scale track is looking very nice. Will you be adding check rails, wing rails and tie bars etc?

Thanks - unfortunately, the terms check rails, wing rails, and tie bars don't translate to this yank, so if you could clarify please?

saddletank · Post by **saddletank** » Tue Nov 25, 2003 11:35 am

3DTrains wrote:
Your scale track is looking very nice. Will you be adding check rails, wing rails and tie bars etc?
Thanks - unfortunately, the terms check rails, wing rails, and tie bars don't translate to this yank, so if you could clarify please?

Heh heh, sorry, should have guessed that American railroading uses different terms

Here's a pic:
<IMG SRC="http://album.atomic-systems.com/showPic ... ntwork.jpg">

Tiebars are flat steel stiffening plates that connect the moving blades of the point (or switch) at their extreme open end and prevent them flexing relative to each other. Looking carefully at some of your screengrabs I think I can just make out what appear to be checkrails.

When will the scale rail pack be finished?

3DTrains · Post by **3DTrains** » Tue Nov 25, 2003 3:10 pm

Ah - "frogs" it is.

Not all details are complete, but items like frogs (check and wing rails) are already in most of the turnouts, and the tie bars are there as well (although I'm not finished with mapping the nut-bolt castings just yet).

The above turnouts were before figuring out the fix for sorted alphas, something Tim Booth nailed some months ago for UKFS (a great inspiration for ScaleRail's development as a NA prototype).

ScaleRail's currently in open beta, with the public release due January. You can keep up to date with what's happening in the ScaleRail forum:

http://www.3dtrains.com/forums/index.ph ... ct=SF&f=48

saddletank · Post by **saddletank** » Tue Nov 25, 2003 4:28 pm

Wow, Marc, looking really good.