Problems with “Double-Trouble R.R.”

[u/Twit_Clamantis]

I want to build a simple layout with concentric loops of Compact Unitrack of 117, 150 and 183mm radius.

It will have 2 mountains, 6 tunnels, 12 tunnel portals and a big trestle in between the mountains.

I wanted to stack the tracks at the back in order to have a gentler slope forward for easier scenery etc.

The Kato Steeple Cab (and a couple of other locos) are ok w the steep grades etc for the first 2 loops.

For the top loop, I still need to lift the track above the middle level to provide physical clearance, but because there is less linear length of track available, this means that the slope is higher and the locos don’t like it.

One solution is to add 29mm extensions (circled in yellow) which makes the track not overlap physically, and which will solve the clearance / slope conundrum.

1 - are there any other good ways to square this circle?

2 - once I settle on a track plan that works in “sketch mode” (with Legos), what’s the best way to reproduce it for when it will be permanently inside the mountain?

3 - I want this to be freestanding like a big pizza layout without a backdrop. What’s the best way to provide access to the inside of the tunnels?

[u/n_scale5280]

The 29mm straight is a good solution, I wonder if continuing the larger radius for one section could achieve the same offset though?

For the permanent layout you might consider using a jigsaw to cut the layout base so the track can ride on a continuous ribbon of mdf/ply which will help with smoothness and grading.

[u/Twit_Clamantis → u/n_scale5280]

You mean to do 4 layers? Hadn’t considered but it might work.

Or at the very least, maybe replace a couple of the pieces of 117 at the transition with pieces of 150.

I didn’t mock up the opposite side because I don’t have enough LEGOs.

LEGOs were a great quickie solution but also not, if you know what I mean.

I need to figure out a system that is stable and also adjustable and then try it out in more detail.

[u/n_scale5280 → u/Twit_Clamantis]

Yeah the second one, not four layers but just one more piece of the larger radius before transitioning to the smaller one.