Minimum height clearance inches/scale feet -- N scale

[OldEastRR]

USED to know this, but no longer have the memory nor the track=planning books that had it. Is is 1.5" or 1.25? This is from the top of track to the bottom of roadbed crossing over (hidden track).

[Chris333]

Isn't it built into the NMRA gauge?

[dem34]

Isn't it built into the NMRA gauge?

Correct. @OldEastRR its a good tool to have if you don't have it. Though one thing to remember its for clearance from the rail height. You will need to manually add the height of roadbed and rail.

[John]

https://www.nmra.org/sites/default/files/standards/sandrp/pdf/rp-7.1_tangent_track_centers_and_clearance_diagrams_2019.01.pdf

[garethashenden]

Isn’t the NMRA gauge only Plate C? Anything higher you’re on your own.

[nickelplate759]

1.5" is 20 n-scale feet.     1.25" is 16' 8" - no way is that enough.
Modern double-stack trains can exceed 20' tall, but older prototype N-scale equipment, if height is to scale, might fit a 20' clearance.

So - the first question, is what do you need to fit under the bridge?  Go get your tallest models (likely either a loaded double-stack container car or a crane) and see how tall that is.
Personally, I'd recommend trying to maintain at least 2" vertical clearance above the railhead.

[MetroRedLine]

Isn’t the NMRA gauge only Plate C? Anything higher you’re on your own.

My NMRA gauge measures a scale 22', which is higher than Plate H (20' 2"), the tallest AAR clearance plate.

[jagged ben]

I recall 1-7/8" for stacks and racks but that probably included cork and code 55 track, so subtract about 5/16 and you are at 20'-10" in scale.  Which is about right because N scale cars ride high.  So say 1-5/8" if you want to be safe with modern stuff.  For older lower plate prototypes you have more wiggle room. 

[wazzou]

My NMRA gauge measures a scale 22', which is higher than Plate H (20' 2"), the tallest AAR clearance plate.

As is mine.

[OldEastRR]

yeah, I've got the NMRA guage, which is fine for precise measurements, but I'm trying to sneak a track under some elevated sections and am looking for the absolute minimum. I'm running pre-1955 equipment so no hi-cubes or double-stacks (or domeliners, since its the NH). I looked at so many layout plans way back when, and 2" was the usual height, tho some layout designers stuck in bare-minimum heights for some over-under track. 1.25" is way too low, I can see. Right now the under track runs right next to the over track, and I want to shift the over track to go over it. At this point I can run trains on the lower line and eyeball how much clearance I have to the baseboard of the upper track -- at least on part of the run. The lower track eventually goes under the upper afte r that one rises some more and that's a 2.5"+ railhead to railhead clearance.

[peteski]

Since it seems that you are trying to figure out the minimum clearance for the equipment you already own, best thing to do would be to take you your  caliper, and using its depth measurement rod check the height of the tallest car (placed on the existing track) you want to travel in that area.  Oh wait, you don't  have a caliper. 

[wm3798]

Be cautious...  If you're running older equipment, some of the details are a little beefy.  I have an old Arnold tank car that I can't run on the Newport and Rock Falls because the handrails on the dome hang up on one of the tunnel portals.

Lee

[nkalanaga]

1.5 inches should be fine for 1955 equipment.  That's 20 scale feet, and many small electric freight lines back then had wires lower than that.

Even Plate C cars are (barely) under 16 feet, and those didn't become common until the 1960s.  So, even with too-tall models, 20 feet should be fine.

[OldEastRR]

Since it seems that you are trying to figure out the minimum clearance for the equipment you already own, best thing to do would be to take you your  caliper, and using its depth measurement rod check the height of the tallest car (placed on the existing track) you want to travel in that area.  Oh wait, you don't  have a caliper. 

Funny ... hey Peteski, you've got a few, just send me one of your extras.

[OldEastRR]

Since it seems that you are trying to figure out the minimum clearance for the equipment you already own, best thing to do would be to take you your  caliper, and using its depth measurement rod check the height of the tallest car (placed on the existing track) you want to travel in that area.  Oh wait, you don't  have a caliper. 

Funny ... hey Peteski, you've got a few, just send me one of your extras.
 Actually I decided it'd be a pain to shift a double-track main merely to widen a curve. The  tight radius (14") makes long trains slow down while the cars go through, then get back to running speed once out of it. Considering I model an eastern RR, I decided that feature was a realistic part of ops for the real thing. There's a  parallel track only slightly wider, but it's a downhill run so no problem.
But at least other modelers remember 1.5" was used on some layout plans.