Hey fella's, I know that model trains can usually only climb a 2% grade properly without stalling or having wheel spin-out when pulling multiple train cars - Her's the situation - On a room size layout in a small room and using a "wrap-a-round-the-wall" shelf style layout that is short of space but you want to have a continuous run around the whole layout and back to the point of origin again - Now this would be no problem on a single level layout but you add an upper level to represent traveling through mountainous area's - So y

In the Model Railroad Planning 2015 article on Gary Hoover's new N&W layout there are a few photos and a brief description of how he constructed a drop gate to access part of the layout.  It got me to thinking that this type of access might work well on my layout as I have to put a gate across the access door to the layout room.  I have gotten underway with some 3/4" plywood for the roadbed and purchased some hinges etc.

Not being a carpenter, cabinet maker, or structural engineer, I need some help.

The common wisdom for big layouts in recent years has been a top layer of 3/4" five- to seven-ply board, with a supporting structure of 1x4 equivalents.

My question: We're doing HO. For a shelf layout with spans of no more than 8' in length and 16" in depth, how far can I scale back those material sizes? Will a well-designed 1/4" supporting layer be sufficient? How deep does it need to be? Would a 3/8" top layer be rigid?

Local Home Depot has 1/2-inch 4x8 sheets of "Sound Deadening Board" that is not as dense or heavy as Homasote.