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Quick mental check: Vertical clearances, N scale

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  • Member since
    December 2021
  • 53 posts
Quick mental check: Vertical clearances, N scale
Posted by jkovacs5 on Saturday, January 20, 2024 11:46 AM

Hi all,

As they say in warfare, no plan survives first contact with the enemy, and the same really applies to model railroading too. As such, my layout, which I've spent about 18 months planning and fleshing out, is no exception.

First major issue was a realization that the room first and foremost needed a lot more storage shelves for all the non-railroad stuff, which completely nerfed my 18-month-in-planning plan as I lost 2 feet of available width for my layout space. But a quick redesign/reconfiguation later, I was able to achieve 98% of my goals in the slightly more confined space (now 19' x 7', instead of 19' x 9'; still a pretty generous area for N scale). The bottom of the helix and the staging yard were the biggest areas changed, not in length or height/grade, just in track and benchwork configuration. And here's where I ran into my one (and only) vertical clearance issue...

A reversing loop at this end of the mainline now needed to be routed within and under one end of an oval helix. To avoid supports for the benchwork and such, and to maintain my mainline bare-bones-minimum 15" radius curves, about a 1-ft section of this reversing loop ducks slightly under the helix tracks with a 1.5" clearance space from top of rail to bottom of the helix loop subroadbed.

Now, this is a little tight. 1.5" in N is 20.0 proto feet, pretty sure my NMRA gauge is 22' proto (1 21/32") to allow for Plate H cars. But I'm running late steam/first gen diesel on my railroad, not double-stacks so I'm not really concerned. 20' scale should accomodate everything from Plate F (17' proto) and shorter, right? Even allowing for scale model inaccuracy in scaling, I doubt I'll encounter any real issues with all "normal" cars and loads. This sound about right? 

Can anyone think of any locomotives which might run afoul with only 20' proto headroom above the rail? Again, I'm later steam (but not articulateds, mostly Mikes and Pacifics, a random Hudson, etc.) and early road diesels (RS series, EMD and Alco cab units, etc.)

Obviously, this is in a hidden section of behind the scenes trackage; I don't care in the slightest that it looks a little goofy with such little overhead space. No one will ever see it unless they're sitting inside the helix to do maintenance or cleaning. I just need it to work!

Thanks,

-Jason

-Jason

  • Member since
    August 2011
  • From: A Comfy Cave, New Zealand
  • 6,172 posts
Posted by "JaBear" on Saturday, January 20, 2024 5:37 PM
Gidday Jason, the only observation that I would make is that there is not really any clearance for something like the Bears paw, if for some reason a derailment happened in that spot. That said, you’ve indicated that it is only for one foot, so…
Your clearance issue is just a variation on the compromises that most model railroaders have to make from time to time.
Have Fun.
Cheers, the Bear.Smile

"One difference between pessimists and optimists is that while pessimists are more often right, optimists have far more fun."

  • Member since
    February 2018
  • From: Flyover Country
  • 5,523 posts
Posted by York1 on Saturday, January 20, 2024 5:59 PM

jkovacs5

Now, this is a little tight. 1.5" in N is 20.0 proto feet, pretty sure my NMRA gauge is 22' proto (1 21/32") to allow for Plate H cars. But I'm running late steam/first gen diesel on my railroad, not double-stacks ...

 

Jason, I have an N layout, and I run double stack cars under two bridges that have two inch clearances.  There is still plenty of room.

I can't think of any problem with 1½ inch clearance -- you should be fine.

I'm not sure what your roadbed will be, but if you ran into any issues, you might be able to gain a little by doing something to that part of the roadbed.

Have fun, and let us know how you make progress!

York1 John       

  • Member since
    December 2021
  • 53 posts
Posted by jkovacs5 on Sunday, January 21, 2024 9:23 PM

Thanks Bear and John. John: Yep, no roadbed being used on the reversing loop, so it's already at the maximum separation I can get. And yes, I was pretty certain that aside from double-stacks, which I don't run anyway, I should be good.

Bear: Indeed, 1.5" clearance would normally be a no-go for these greasy meat-hands. Heck, that's the whole reason I'm going with an elongated oval helix instead of a traditional circular one; minimal vertical clearance for the trains in a traditional circular helix with ~2" vertical clearance between helix loops is just not the same as the minimum clearance that this klutz with 10 left thumbs needs to work on/clean the track. (Tried that once with a double-tracked helix on a previous layout, and I hated the inability to really do anything with the trackage once the next loop went up, ended up stalled and dejected for 6 months before I pulled the trigger and 86'ed the helix idea altogether.) Fortunately, this 1-ft section undercutting the helix loop is only about an inch under the edge, and that edge is fully exposed for the whole 1-ft ... derails or even a cleaning rag won't be a problem.

Cool, I thought I was in the clear for 99% of equipment out there. Worst case, if a visitor brings their double-stacks, they'll just have to drop into the staging yard and run-around instead of taking the reversing loop. 

Thanks for the sanity check!

(Edit): John, forgot to mention, but I'm taking pics galore and a few shorter videos now and then as I go. At the very least, I figured I'd start a build thread here, and if I get comfortable enough doing voice-over work, I'd like to start a new Youtube channel to document the build, outline the plan, etc. But first I need to build a backlog of stuff to show. I'm an archaeologist by trade, so I tend to get pulled away from home and the layout for weeks or even months at a time, and I'd like to get a few months of updates ready first, otherwise I'll end up being one of those Youtube channels that go dark for a year at a time.

-Jason

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