Where to place cork roadbed?

[doctorwayne]

The main purpose of the cork roadbed is to raise the track atop a profile similar to that used by the prototype.  While it does have some sound-deadening qualities, by the time your track is fixed in place and ballasted, there is virtually no difference in the noise which the trains make as they pass over the different areas. 

In the photo below, the tracks in the foreground are on cork roadbed, while the sidings beyond are sitting directly on the plywood.  The transition between the two areas can be seen at upper right.  It extends about 18" from the end of the turnout off the main line to the start of the turnout at the distant road crossing.  I glued the cork in place almost to the crossing, and when the glue was completely dried, used a sheet of #36 sandpaper wrapped around a block of wood to taper the cork down.  It took perhaps two or three minutes.  This technique won't work on the Woodland Scenics foam roadbed.

Here's a view from track-level, looking in the opposite direction.  The track at left also drops down to tabletop-level for the engine servicing area.  If you look closely at the crossing in the distance, you can see the difference in track elevation between the mainline and the stock pen siding.

I found this shot while looking for the photo at the end of this post.  It's taken with the camera sitting on the layout, looking out towards the aisle.  The camera is sitting roughly where the lumber is piled in the first photo and at an angle looking towards the loco servicing area.  Just beyond the track in the lower left foreground, you can see the transition track sloping down from right to left:

Here's another view looking in the same direction as the first photo.  In the distance, at about where the train is located, the cork roadbed again begins to taper down as it rounds the bend:

Beyond the bend, both main lines and all sidings are laid directly on the plywood.  I used cinders alongside the ballast to give the illusion of a slightly raised roadbed. 

All of this track is directly atop the plywood:

And finally, the straight part of the two main tracks through this small town were layed on plywood roadbed - I had run out of cork and cut some 1/4" plywood to the same profile as the cork roadbed.  The few trains that don't stop here are no noisier than anywhere else on the layout.  All of the sidings on both sides of the main are lower, sitting directly atop the plywood.

Depending on the area and type of track which you're trying to model, cork works well, as does laying track directly on the plywood (or foam).  Having helped a friend lay track using W.S. foam roadbed, I'm not a big fan of it.  

I think that a good combination, at least for mainline trackage, would be to lay cork atop extruded foam, then use a hot-wire cutter to form trackside drainage ditches, although this can also be modelled using plaster-over-screen scenery.

Wayne

 

 

[R. T. POTEET]

Here is a worthless opinion:

As a longtime user of Homasote® I would lay a sheet atop my 3/8" plywood subroadbed and top that off with sheet cork. I would lay out my yard track location and then chisel the cork out from between the track location. I would fill this resulting depression in the yard surface with gravel leaving a few depressions in this gravel surface where I would put some water indicating water still standing after the last rainfall. I would lay regular cork roadbed off the mainline to the yard surface and sand it down for a transition between the heighths.

To detail a yard you need to go out in person to trackside to see just what a yard looks like.

[fwright]

rjake4454

Hi guys, I'm starting a new layout, first task will be building a yard, I have seen many photos where people lay the track directly on the plywood in a yard, with no cork underneath. Why is this?

There are 3 reasons for the use of roadbed under model track.

• it raises the track to simulate the raised roadbed of prototype mainline track.  Prototype yards tend to be fairly level to make it easier for the crew to walk among the cars and track.  Also, the slow speeds in the prototype yard reduce/eliminate the need for the raised bed of gravel (ballast) on the main line.  As a results, prototype yards often don't drain the water away as well as they should.
  
• it reduces the noise of the trains, especially as compared to directly on plywood or foam.  Note that this has nothing to do with the prototype.  At slow yard speeds, track noise is not nearly as much of an issue on our layouts.
  
• the roadbed needs to provide a smooth, flat surface on which to lay track.  Otherwise, derailment-causing dips and peaks occur in the rails.  If rougher grades of plywood are used, it is difficult to get the surface smooth and flat enough for dependable track - you end up depending on the vertical rigidity of the track to save you.

For handlaid track, in addition to the above, the roadbed has to be a suitable material for fastening the rail to the ties and roadbed, and keeping the ties in correct alignment.

In my observations, the third bullet for roadbed is often ignored, to the detriment of the trackwork.  Most cork roadbed, after it is laid, will have some bumps and ridges.  Taking the time to eliminate these with sandpaper will result in better trackwork.

If you use a "squishy" roadbed which passes any irregularities from the subroadbed through to the top surface, then the subroadbed needs to have the flat, smooth surface.  Again, my observation is that the combination of foam with any dents or rough plywood subroadbed and a soft, squishy roadbed will cause problematic track.

just my experiences and observations

Fred W

[Aralai]

I am using the WS foam in sheet form for my yard and the strips for the rest - it is all the same height so no transition worries.

[mobilman44]

Hi!

I'm currently building a layout also (HO, 2 level, 11x15), which is essentially a replacement of one I built in 1993.  The lower level staging area is complete, and I used cork roadbed over the 1/2 inch ply base.

The main level will have cork roadbed for all main and sub-main trackage, while the yard, terminal, and industrial sidings will use sheet cork, which is about 1/2 the height of the standard cork roadbed.  There are a lot of ways to make this transition, and that was a subject on this board a couple months ago (you may be able to retrieve it).  In my case, I will experiment with different methods before I pick one......

May I add a couple of things here.......  I am not criticizing anyone's layout or methods, but I would not lay track directly on plywood.  Cork or homosote or whatever used over the plywood will dampen the sound, look better, and bridge discrepancies in the wood surface (esp. at joints).

You said you were building your yard first.  I guess there is nothing wrong with that but I've always seen the mainlines, sub-mains put in before the yards.  Maybe I'm missing something here, or maybe your situation dictates what you are doing, but it seems odd to me.  Again, I'm not criticizing, just curious.

Hey, all that really matters is that you ENJOY !!!!!!

Mobilman44

(certified train nut since age 10 -1954 - modeling the ATSF circa 1950s with a minor in the IC)

[jrbernier]

  You can use a 'sureform' tool to sand down a nice transition with cork roadbed.  The W/S foam roadbedd does not seem to sand very well(sort of rips apart).  I am not sure I would put your yard on plywood.  You can buy sheet cork.  Attaching it directly to plywood will not allow any space for the throw bar to move smoothly(and trying to cut a slot in plywood will be tough).

  I use 1/4" thick 'Homabed' for my mainline, and 3/16" cork roadbed for my yard/sidings.  I sand a 1/16" transition about 12"-16" long with my 'sureform' tool.

Jim

[rjake4454]

Hi guys, I'm starting a new layout, first task will be building a yard, I have seen many photos where people lay the track directly on the plywood in a yard, with no cork underneath. Why is this?

Secondly, if I were to do this, at what point would I begin laying cork roadbed and how would I transition the two unequal surfaces of flat plywood to the elevated road bed. Wouldn't this just be asking for trouble?

I want to ballast my rail yard, but I can't decide whether I should just lay the tracks on the plywood then ballast them, or to do it the normal way of laying cork bed first, then ballsting the track. Which do you suggest?

Sorry my question is kinda hard to explain, I hope I made myself clear enough.

BTW, should I use regular cork, or the WS road bed (its black I think)?