So it seems that everyone agrees that roadbed/ballast should be thicker on mainlines than it is on sidings, spurs and branches which should be thicker than that used in yards. From photos I’ve seen I’ll agree with that, it looks better.
What I think I may do is run 2 layers of cork roadbed under my mainlines, 1 layer under non mainlne and my yards (staging) directly to plywood. I figure I’ll glue/ caulk the cork down and glue/caulk track on top and probably tacking/spiking the staging tracks.
Other than the extra expense of doubling up the cork under the mains does anyone see any problems with this? Would this make the track more likely to shift or heave? Any better things to use for thicker roadbed (other than Homasote)? Do you think this may make staging too noisy or should those be glued too?
Personally,I think it’s overkill. If you’re in HO, use HO roadbed for mains and N for sidings and yards, or just HO for mains. Most sidings are lower than mains anyhow and it’s easier when planting structures and roads down to ground level tracks. See how it’s done in real1:1 railroads.mh
I use Homasote roadbed throughout, even for my narrow gauge, because it allows me to get the track right and keep it right by adding spikes where needed. But 1/2" Homasote is way too high for any 1900 era roadbed. Narrow gauge - especially logging - often used dirt ballast on minimal grading, and stone was only used where the extra drainage was critical.
So the tried and true method is to raise the level of the ground, not worry about lowering the track. Anything from plaster shell to 1/2" thick foam pieces to Homasote and plywood chunks to foamcore fit between my tracks to support the scenery.
And/or use a grid system of benchwork with cleats and risers to support the subroadbed, and you can easily have many subtle variations of track levels - and without abrupt transitions between the levels. You can take an existing flat top layout of plywood or foam and cookie cutter the top with a jigsaw or knife (depending on material). Then add risers and cleats from underneath to position the track at the desired height - this was stan
Yes overkill is an understatement. How about 1/2 inch homabed /homasote for the mains going to cork on sidings and yards?
As an aside. not all sidings are lower than the mains. Some pool service caboose tracks were above grade and caboose would roll by gravity to the departure track. Also topography of an area dictated industries would be above the surrounding area. These areas could be modeled with either a split point derail or flip type derail to protect the main.
I used cork under much of my mainline, but not all of it. Here, the main tracks are on cork, with the sidings lower, directly on the plywood sub-roadbed:
Here, both mainlines and the sidings are placed directly on the plywood, with ballast and groundcover serving to differentiate the two:
Here, the mainline is again atop cork, but the trackside land (patching plaster on screen) drops away, easily done by placing the roadbed on risers, then contouring the ground as desired.
This can also be accomplished using foam scenery - a hot wire cutter allows you to shape ballast, roadbed, subroadbed and fill all in a single pass. There was an excellent article on this topic by Bill Darnaby, in the June 1994 issue of MR.
I agree that idea seems to be a lot of extra work and effort for such a little pay off. Personaly I wouldn’t worry so much about it, many grade differentials at yards were 6-12" in the real world which roughly translates to invisible in HO. Industrial sidings most likely drop to ground level soon after the switch so you can model that by putting the track on the supporting sub roadbed. It really depends on how much work you want to do.
Why worry about noise? Ever been to a real rail yard at work? For a real treat stay at the Quality Inn across the street from the NS Enola hump yard…scrreeeeeeee bang…screeeeee bang…screeeeee bang…screeeeeeeee bang…
The layer under the top cork for your mainline can be anything with consistent thickness. It doesn’t have to be the expensive spread.
Personally, I don’t use cork. It doesn’t fare well where 100+ degree temperature and single-digit humidity are the norm for four months of the year. My choice is fan-fold underlayment, thin extruded foam used under vinyl and metal siding. The basic thickness is about 3/8", which looks good full height for mainline roadbed. I simulate lower ballast height by raising the adjacent ground surface with extra layers of ground goop or similar. If I wanted to lower a siding (to get the appearance of some North American prototypes I have seen) I would shave off about 1/8" of the foam roadbed. You can probably get the same effect with HO cork under the main and N-scale cork under the siding.
Since you asked, I would do as horton suggested, or just use the same HO cork for the mainline and passing sidings and use a slightly darker ballast to define the difference.
On my MRR, my passing sidings are that same height as the main. Industrial complex tracks and yard tracks are on the base top (no roadbed). Ballast colors define the type of track. Light gray for the main, medium gray for passing sidings, dark gray for industry tracks, and cinders mixed with dark gray for the yard. I also have a branch line, and where it takes off from the mainline, I am using Buff colored ballast.
This is how I did my yard and main line. The main is 1/4"cork, and the yard is laid on 1/8" cork sheet from AC Moore. The main ballast is WS med. grey mix. The yard is fine cinders, weathered with dry, black, Tempora paint. The 1/8" difference is about 12 scale inches. DJ.
You can get Homabed roadbed (manufactured from Homasote) in 2 different thicknesses (.240" & .125") including tapered transitions and a variety of accessory pads for turnouts, crossings and yards; also milled for 2 different shoulder slopes (45 & 60 degrees). Check their website and order a sample kit.
N scale roadbed, I forgot all about that trick. But would the N be wide enough for HO track?
Subroadbed is cookie cutter plywood but I’m not sure how fleible it would be for lowering a siding without just creating a dip next to the mainline. I’m not looking for major elevation changes or grades made from cork, just visual separation between track types.
Different color ballast is actually quite convincing. But I’m modeling former NYC and PRR mainline so a large ballast mound under the tracks wouldn’t be a detriment, one reason I’m using code 100 rail on the mains.
I disagree. The height of HO scale roadbed is prototypically accurate, or pretty close. If you doubled up, it would look like your trains are running on a fill, and it wouldn’t look very good in most cases.
As others have pointed out, it’s better to either use a lower roadbed (N-scale – and you can just add a piece in the middle) or use plaster, Sculptamold, or even extra ballast, to raise the height of the surrounding terrain so that the ballast looks lower.
My general observation is that mainlines have the general profile (the beveled edge so to speak) that cork or other material roadbeds provide. Sidings, at least rural sidings, typically do not. I do like the look of sidings that are slightly lower than the main. Like others above, I also use N scale roadbed for sidings but I get the Woodland Scenics material in large sheets so that I can cut it to fit.
Reference your question about the width of the N scale road bed: I use it on my HO sidings and what I use is about the same as the HO tie width. I don’t split it on straight sections. This is not an issue as you can make your own ballast contour. To tell you the truth, the profiled bevel on most model roadbed is too steep to be realistic but it saves space and ballast. Shhhh. Don’t tell everyone that. And don’t tell them that the ties are often too short for even the classic era. Shhhh. And bricks on most model buildings and brick sheet are too big. Shhh… And. … And…
