Multiple Level Layout - Clearance

[Rivet Miscounter]

What is the rule of thumb for multiple level layouts regarding clearance?     Definition of clearance would probably be the open space between the lowest point in a valence and the lowest point of the top of the fascia.  Or in lieu of that, the bottom of light fixtures to the lowest scenery grade.   Maybe exclude outliers like a river that dips down, just to get an "average" aka rule-of-thumb.

I would say frame this (no pun intended) as an N question since most of you have that frame of reference.

One (not-N) question I would have is what were some of the "Old School" double decker layouts using as their number?   Mostly thinking of the HO layouts we'd see in MR in the day....the Ohio Southern I think it was?
EDIT: See https://www.trains.com/mrr/how-to/track-plan-database/ho-scale-ohio-southern although I can't find mention of height but maybe I'm missing it.

I realize some of it doesn't scale directly from HO.   I recall designing my only previous multi-level layout that I figured you need a minimum of 4" to reach a hand in to retreive rolling stock. (that's just the space for the hand, not counting the actual height of the rail and rolling stock)    That probabaly wouldn't impact a scenic'ed level as you'd probably want more than 4" regardless of scale. (I know, TWSS)   But could come into play if trying to have a minimal height staging yard for example.

[Rivet Miscounter]

The above question was forumulated as the result of this photo... (also not N)

[ Guests cannot view attachments ]

...and the fact that, well, I want to attempt a multi-level layout again sooner than later.

In the photo, you can see the top of the boot box in the far top right corner of the pic, and that would be the N equivalent of about 7-1/4 inches tall.   I started thinking about what the minimum that, say, a three-level layout could be built.   I'm thinking using a minimal wafer of a sub-base, maybe something like 1/4" plywood (or gatorboard?) and 1/2" foam cantilevered straight out from the wall. ( no angled wall brackets, etc.)    Mount small form factor servo switch machines top-side of plywood (still under scenery) and use LED light strips for minimal height lighting.   I think the actual substructure could be....an inch tall? 1-1/2 tops?   

[Rivet Miscounter]

Then back to the question about clearance....would 8" be enough?   (yeah, yeah)

I know that is subjective.    I'm modeling a mostly flat west Texas area, so no mountains or deep revines but guess what......grain elevators.   So they would fill the backdrop or be cartoonishly short as foreground structures. (and/or also hit the "celing" of the next level.)

EDIT: For reference, the Walthers N-Scale ADM Grain Elevator is 9" tall.

[C855B]

>...minimal height staging yard...

There's where you get in trouble. You need enough clearance to be able to reach in to, say, push a recalcitrant switcher past a spot of dirty rail on the third track in without knocking over the two trains in front of it. And why was the track dirty? Not enough clearance to comfortably clean it regularly. I've seen a couple of HO layouts allocating only six or seven inches between levels and they immediately registered in my mind as maintenance and operation nightmares.

While I don't have any multi-level benchwork at this point, I've spent a lot of mental energy engineering the far-future portion of the layout that will be. I'm allowing a foot, minimum, with enough space allocated to the overall layout design for a nolix connecting the two levels.

[CRL]

It depends on what you’re trying to accomplish with the layout and what is going on track-wise on the lower level(s).

The absolute minimum clearance would be the height of an NMRA track gauge above the railhead to the bottom of the bottom of the upper deck for whatever era equipment you want to operate. That’s ok for a short underpass/overpass crossing but you’d never be able to access the lower track for maintenance if it was any longer. Beyond this absolute minimum, allow as much additional clearance as you can so you can reasonably perform any maintenance on the lower level tracks.

[Ed Kapuscinski]

Have you read Tony K's multi-level layout book?

It was actually really good reading before I started my current build. There's nothing earth shattering in it, but it was a good roundup.

There was good content about height and spacing.

Personally, I did testing and prototyping before I started. I highly recommend that approach since we're all different.

[nickelplate759]

Whatever you choose, you'll want to consider maintenance requirements as well.  As an example, I wouldn't want to have a turnout with only 12" clearance above it at the back of a 12" deep shelf.  Too hard to work on, and there's a decent chance I'll eventually need to.

[Ed Kapuscinski]

Whatever you choose, you'll want to consider maintenance requirements as well.  As an example, I wouldn't want to have a turnout with only 12" clearance above it at the back of a 12" deep shelf.  Too hard to work on, and there's a decent chance I'll eventually need to.

This. This. And this.

I am finding myself sore from installing turnout throws because the height I have to be at is perfectly between standing and sitting height.

[C855B]

I am finding myself sore from installing turnout throws because the height I have to be at is perfectly between standing and sitting height.

I have one of those rolling mechanic's stools for that very reason.

[Rivet Miscounter]

Man, really great feedback so far.  Thank you all.

[Rivet Miscounter]

I've spent a lot of mental energy engineering the far-future portion of the layout that will be.

This is practically my model railroading mantra right now.   

I went back and clarified about the minimal clearance...it would 4" for the arm/hand to reach in and then the additional 2"+ for roadbed, track, and rolling stock for N.   So practically speaking 6-7" would be the absolute minimum in my mind.  That would be "turnouts in the front, pure staging".

So the real crux of the question lies in the 5" between that 7" minimum and your (and what I expect to be most) minimum of 12".   And I think the ADM elevator would work as a good compromise solution vs more accurate height structures, if maintaing a minimal height remains my objective.   Probably would have to say 9-1/2" to 10-1/2" is my minimum for now, so now we can shoot holes in that.   That would give me an overall 11-12 inches per level height.

[Ed Kapuscinski]

I have one of those rolling mechanic's stools for that very reason.

Oh yeah. Excellent idea. I bet you might even get a benefit from a Topside Creeper: https://traxionproducts.com/products/topside-creeper
As for me, the whole thing is too awkwardly positioned for me to benefit from anything aside from ibuprofen.

[Scottl]

I'm planning a double deck layout too and this has been on my mind.

I was aiming for 14" between track tops.   What becomes very important in relation to this measurement is how thick the upper deck is.  Like you, I'm contemplating how I can make it as thin as possible while still being strong and functional. 

I have contemplated constructing the upper deck out of some kind of structural panels, with a wood perimeter frame and thin plywood skins.  Instead of sheet foam, I was envisioning filling them with spray foam because that would provide uniform adhesion all around.  I have also thought about running an embedded 1" aluminum U-channel lengthwise relatively close (but not at) to the front.  This would provide further stiffness and eliminate sagging of the panels, while offering an accessible conduit for wiring and LED strip lighting.  The costs would be higher with the aluminum, but I think it is possible to have 1-1.5"-thick base panels.  Further stiffness would come from securing layers of foam board on top for scenery contours.  Finally, where the scenery allows, hidden longitudinal wood pieces would further add strength to individual panels.

I'm still thinking about this, but it is an important decision in terms of my helix size and scoping scenery and access to the lower deck.

[Rivet Miscounter]

we're all different.

I haven't read Tony K's book but I'll likely put in my shopping list.

We're all different no doubt.  I'm tall and wide, not a good combination for a model railroad room but the good news is I can mostly design around me being the worst-case scenario for width, and the extreme limit for height.

Also, I want to design it for ops...likely only 2-3 at a time but I at least want to have that option.  So then you have to design for a more common set of dimensions.

Over the years, I've come up with numbers--some of which I confirm the origin but others not so much--that were used for designing height.
1. For my multi-level layout, I remember coming up with the number of 54" being the max height that would be "normal human" compatible.  And even that might be a little high to comfortably view and operate trains.
2. My Saginaw Transfer layout was on Ikea "Billy" bookshelves at 41-3/4" plus 3" layout thickness for 44-3/4".   That felt like a VERY comfortable height to me.

[C855B]

Oh yeah. Excellent idea. I bet you might even get a benefit from a Topside Creeper: https://traxionproducts.com/products/topside-creeper
As for me, the whole thing is too awkwardly positioned for me to benefit from anything aside from ibuprofen.

Topside Creeper has been on my radar for a while, just haven't pulled the trigger. When I'm gearing up for more layout work at the end of the summer (remote cabin + lawn maintenance at home + new dog park/bar = very little train time) I'll likely invest.