If you already have RailModeller Pro, I've made my layout available to download on the community layts section of RMP under N scale.
Originally, the top deck was going to be Peco track but I've had such good results with the Kato track after messing around with it for the last few years that I redesigned the top deck with Kato Unitrack to match the lower deck. I've also made the design more mountainous.
There are only four areas that do not use Kato track. Two are on the lower deck which will be a very early 1950's style intermodal yard with ramps at the end of each track and the roundhouse area (Walthers 130'). The top deck I've used flex track for a couple of bridges although on the plan the largest bridge actually shows three inline single track Kato bridges but I will build it with another style bridge, possibly Micro Engineering's bridge so of course I will not use Kato track on that section. The final bridge is on the top deck where there is a partial curved bridge which I may need scratch building but it's not too big.
On my layout, the helix is 5 layers with 2% incline, 50mm (2 inches) clearance. Equally all inclines are 2% using Woodland Scenics risers and all bridge clearances 50mm (2inches) as per the helix.
Anyway, feel free to download and build yourself or even modify my design and add it to the community layouts. We all have our own ideas and it's great for other railroaders to modify an existing design.
One last thing, I haven't updated much here or on my YouTube channel for a long time because I'm still working away and my rotation onboard the vessel has been extended to mid April for logistical reasons.
The good news is I'll get the full ten weeks off next rotation home which is a lot of train time!
Thanks for reading.