Bonus Room Shelf Layout

[faraway]

...the foam isn't conducive to mounting switch machines and such under the layout...

I have seen the foam quite often on US layouts. The base is at least 1" thick, often up to 2". It might be a good solution for my next layout to ban the noise very effective.
How do you do the switch machines? Because you are using that technique so often I expect there is a "US standard" solution?!
I need to mount my engines under the turnout. They are very powerful and need a solid base. As Murphy's law is always applicable free access from underneath the layout for repair and adjustment must be ensured.

ps. Should we move that topic to another sub board? I do not want to hijack the Bonus Room Shelf Layout thread.