Ensuing Shelfie Angled-supports Quest

[MarkInLA]

Hi.
I'm off to a slow start, but off..Made final decision last night while at an HDepot as to what shelve's materials will be for this small L, switchback in HO, which, instead of the usual 1X4 I'm going 1x3s for grid-frame and risers..Top will be their version of Homasote (I believe) paper-mulch type sound deadening board. Took home 1- fir 1x3x8' $2.40
It will have but one cookie-cutter 4"wide up-down ramp/right of way to valley switching scenes from level, bigger main 6"ish above (main= one big 90deg curve in corner/live depiction of daily L&N RS3 freighter turn unhooking from cars & caboose and motorin' on down the ramp to deliver/collect cars).. Local RR.Co. of small steam reside down here too, engine house, wye into corner under main, Or wye lft /Rgt legs will instead be tracks for coal mine at unseen mid leg..
Jury is still out on that.. It is half fictitious Hagans (type) SB....
Any road (as Ringo says), what is the better/wiser/does it matter/way of supporting the shelves ?......
I've decided to skip the triangular plywood shapes deal, and with either 1x3 or 2x2, run angles from front edge-fascia into molding on wall at floor, making approx. 4-5 per wing of bench.
Or, is it the more hairy job of (if each shelf were say, 1' wide) to make 1'x1'x1'-ish 2"x2" triangles (requiring more wall stud intrusion, after rear stringers' ) ?
Shelve will be about shoulder height. lower level sub roadbed's ground zero will be approx 2" above that on risers..

Mulch tanks,
M

[nickelplate759]

Hmm - a few thoughts:

First, don't use unsupported Homasote (or similar) board.  If you really want Homasote for your top surface, support it with at least 1/2" 5-ply plywood.   Otherwise it will sag eventually.

Second, how much bracing you need to hang it just from the will will depend a LOT on how wide the shelf is, as well as how much weight it will need to bear.      I prefer to use steel shelving braces - easily found at hardware stores in widths up to 20", which is more than long enough to support a shelf up to 30" wide.  These aren't the stamped steel angle braces, but the more substantial ones with a piece of steel forming a triangle between the top of the brace and the wall.    A little more expensive than using wood, but also easier and stronger.  Here's a link to a 20" one at Home Depot:   https://www.homedepot.com/p/Onward-20-in-White-Heavy-Duty-Shelf-Bracket-494W20B/202205511?source=shoppingads&locale=en-US&mtc=Shopping-B-F_D25H-G-D25H-25_4_BUILDERS_HARDWARE-Multi-NA-Feed-PLA-NA-NA-BuildersHardware_PLA&cm_mmc=Shopping-B-F_D25H-G-D25H-25_4_BUILDERS_HARDWARE-Multi-NA-Feed-PLA-NA-NA-BuildersHardware_PLA-71700000035978695-58700004046980559-92700060790923492&gclid=Cj0KCQiAvvKBBhCXARIsACTePW8Aj3d9Foe-ONHJF1Z-lisirALjOtk1y0Ren_v1YxBoEcRj-tyIcygaAsb3EALw_wcB&gclsrc=aw.ds

[MarkInLA]

n759
My $ is tight but I will look at the steel angle braces.. Far as sagging (without ply under mulch board), was thinking some sagging here and there would be OK, same as 1:1 scale..
If it got bad enough I could always add another riser/cleat under such a depression. Yet, since I am fully aware the model is less forgiving that way I will give ply sub-sub-roadbed some extra thought, though...
Thanks for the help, M

[nickelplate759]

You don't need that steel brace at every stud.  They can carry a lot of weight.  On my last layout I had one supporting the end of a nearly 8' span (actually, inset from the end about 18").   I'm not arguing for such a long span (it requires engineering of its own not to sag), but just pointing out that you don't need a lot of braces.  One every 2 or 3 studs would be fine with the right structure above it.

[MarkInLA]

Excellent heads up !!! I savvy dat !! I was picturing supports at near 4-5 per wing and adding up the cost for about 10 on the HomeDepot pics.. And speaking of that, I did see one for about $7 that would work out to be more like only 6-7 needed = only $50-ish TTL..
If I instead made solid ply triangles I believe I would have to buy a whole 4 x 8 x.5", to make them..@ about $20 sheet..Yet, if gone at logically maybe it'd kill 2 birds with one stone, bearing the ply sub-sub roadbed talked about..
But I also keep picturing making triangles using 1x3s, same as open grid fame (Yeah, I know. Maybe they'll shrink) .
But I am really glad you brought that up !! Yes ! If frame is fail-safe sturdy lengthwise, less supports needed !! Hey ! We're making a 'bridge' ! And I know many ways tooo dooo dat !!
Also, with, say, 8" Masonite fascia, it's even stronger !! 
I love the smell of carpentry in the night !!!
M