Tony P says:

Questions, do you want to be able to fold it away when you are done? If so you will need to attach it to the wall with hinges at the studs in the wall, piano hinges or something stronger. Is it going to be a permanent set up just hanging off the wall or will it have legs to the floor. However you are going to do it, you will need a strong, (as with any layout), foundation. Purchases Roberts E book and it will give you everything you need to accomplish this. For ex: Plywood with 1 x 2s framing, you may want to put styro foam over the ply or just cork road bed. If just hanging off the wall you will need good bracing and if standing on the floor if fold away you will need fold away legs or if permanent, permanent legs.Also checkout Model RR magazine, they have a lot of ideas for what you are looking for. also you can make the shelf as wide as you want but then it becomes more of a standard free standing layout that you can just push against a wall and move back out when you need to work on the back side of the layout. that is important if you have back problems and or getting older. things always as it seems to go wrong at the unreachable side of the layout. so this could be a problem even for the younger modeler. So you see the possibilities are endless. Let us know how you make out with your project.