The "car cassette" yard is the railroads interchange with the outside world. The interchange doesen't have to be a cassette or the casette necessairly in that location. It could be a fixed part of the layout, or eliminated and a track on the main table designated as a interchange. Alternatively you could eliminate interchange of cars completely. Many isolated railroads hace existed.
A cassette lets you add and remove cars (and engines) without having to physically pick each one up individually.
I tried to sell my two cents worth, but no one would give me a plug nickel for it.
I don't have a leg to stand on.
Hi DSchroeder,
you should try to draw your plans; it might be revealing.
When using Kato snaptrack it is completely impossible to build the Mt C & C in the space you have. Even when using the sharpest turnouts and smallest radius.
You might pay attention to the concept of staging.
Smile
Paul