Finding the grade.

If you use the 2 inch foam on some kind of a firm base it will work.  O scale engines are heavier than HO scale but many O scalers tend to over estimate the weight and overdo bench-work, bridges, etc.

Thanks John, for the info I do plan on running some big steam side by side on those lines.

It appears you have a very decent sized area.  What struck me was/is how will you reach across the layout to install, repair, maintain equipment and structures?  Have you given any thought to a design where you could access all areas of your layout without ducking? 

There is a walk way threw the center in these pic it is hard to see.

That's a good size layout.  Should be a lot of fun.

I built my grades using Woodland Scenic Risers on one end and tapered Styrofoam on the other end.  I have a U shaped, more like a G shaped layout.  I only went up six inches and have plenty of overhead clearance.  I have a double track main with O84 and O72 curves.  The Woodland Scenic riser are four inch and two inch combined to get to the 6" height.  My Grade is about 3% on that end.  I had to put four sets together to make the grade wide enough to fit both tracks.  On the other end I had more room, so I stretched the grade out.  I found a semi local company that makes Styrofoam blocks and I had them cut three tapered pieces 48" long by 24" wide.  One piece is tapered from 6" to 4", another is 4" to 2" and the remaining piece is 2" tapered to about 1/8".  The 24" width allowed me to extend a 4" high section 8' where I added a turnout to run into the staging area at the end.  I put the 4" to 2" at a 90 and ran it into a 2" piece of pink foam and on the end of that I used the 2" tapered piece set at a 90 to finish out the long sweeping curve.  I have test run a MTH Big Boy with no deflection.  The track spreads out the load.

Jmiller that's just what I need for one end, the other end I have to go from 7" down to 3".  I have a double track main with O81 and O72 curves at 4 1/2" center rail the same as the Atlsas double pratt bridge. I had to put four sets together to make the grade wide enough to fit both tracks, could you give me a little more info on why? for the grade or the width to hold the track. And are you happy with Woodland Scenic riser.From  I hope you don't mind all ? but really like what you have going on in the photo's

Charles7777.  I had the Woodland Scenic risers left over from a failed attempt to build a large n-scale layout.  I thought it would be easier to get a nice even grade.  I'm not that steady with a saw.  I went to a large scale train show and had to have it.  I'm using Lionel Fast Track.  I have Kato Unitrack and the Fast Track looked like a over sized version.  Another reason I went with Fast Track is I went to five large train stores with in a couple hours from my house and asked their opinion.  Four of the shops recommended Fast Track.  None mentioned anything about a noise issue.  I don't have a problem with the noise as I 'm a little hard of hearing.

The Woodland  Scenic riser are 2" wide.  The track is about 3 1/2"  That's why I used two sets.  I figured that 6" would allow enough clearance for the train to cross over the track.  On the one end shown in the photo with the bridges I have about 20' of run from under the bridge to the center of the bridge.  Installing the risers is easy.  I connected the track first and slid the risers underneath.  I used the 2" risers and built the ramp up to 4" height and used the 4" risers with 2" riser set on to to reach the 6" required height.  I used pin's to hold everything in place than hot glued to secure it.  The above picture that shows the separation between the tracks is just the way the track geometry worked out.  The outer loop has a short straight track that I needed to add so the bridges would fit with a little space between the bridges.

I work slow on the layout and with my job I might be away for an extended period.  I like to do a little and then analyze what I have done and think about ways to improve it.  I found some 6" X 6" X 12" Styrofoam blocks at a school art supply company and thought that would make a nice bridge abutment.  They were also the right height for my elevated section.  I found a company called Polystyrene Products that was about 30 minutes away and I drove over there during an extended lunch and asked for 12" X 6" X 48" block of foam.  They only charged me about $40.00 for six pieces.  I took them home and removed the temporary supports and slid them under the track.  I had more room on the other end to make the downward ramp since the track didn't cross over the tracks. 

I first used 2" pink foam and slopped it down and stuck shims underneath it.  I wasn't satisfied with the outcome.  I called the foam company(410)804-5274 and asked if they could cut the foam blocks with a taper.  They have big hot wire cutting tables that they just move a wire.  They said they could and not knowing how I was going to make the risers I ordered 24" X 48" blocks.  One tapered 6" to 4", one 4"to 2" and the other 2" to 0". 

The 6 to 4 is in the picture. I had to cut some of it away for clearance on the lower track curve.  It's installed at a 90 degree angle from the back wall.  This connects to a two 2" X 24" X 8' pink foam boards stacked on top of each other.  There is a left hand turn out on the flat section that will lead to my staging yard.  At the end of the 8' pink foam the 4" to 2" piece is pictured above.  this connects to a 2" foam board and the remaining tapered board is on the other end.

I hope this answers your question if you want to know anything else feel free to ask.

Jim

I use plywood "cookie cutter" subroadbed. For grades I attach risers/blocks over large distances, 2-3', with temporary supports in between. I use the Micromark grade meter to adjust the grade and then permanently fasten the widely spaced supports. I then fasten the intermediate supports. It is easy and quick.

Charles7777, I think the polystyrene foam would work for your application.  I intend to cover mine with plaster hard shell at the minimum to fill in the cracks.  I put the phone number for the company I used.  The stuff doesn't weigh anything so shipping might be cheap.  You might find a local company that makes polystyrene products.  The company I found makes insulation panels that fit between the studs. 

Here's the Micromark level I mentioned.  Works very well.

Like the photos.  It's amazing because twenty years ago this hadn't been thought of.

Here's a little gadget I made for doing grades.  This particular one is for 2% grades, that is 2 inches rise for 100 inches in distance.  So the wood piece is 25 inches long with a 1/2 inch block under one end.  Then place the level on it and raise the roadbed riser until it is level, screw into place and move on to the next riser.  Make sure you are also level crosswise as well.  Russ

Smart phones have a free APP for that

Clem

Foam will work just fine, and there's several ways you can create the rise in elevation. There's no such thing as over building the bench work/table

Thanks John.... Backdrop Warehouse