I don't have ''60 plans'' to hand at the moment....but....our small layout is based [loosely] on one of the first two plans in the book, the simple oval, passing loop and two sidings ...
[turntable is an ''add-on'''not 'unfeasible' even on a small layout, as with clever stage management...ie oval, and kickback siding, disappearing into tunnels, or under bridges......''suggests'' that the turntable is at the 'end ' of a far bigger complex, which is off-stage.......and actually bears no relationship to the original, 'on-view', station........somewhat like a 'preserved' line? Gives son an opportunity to have, on line, many more engines than such a small layout should comfortably accomodate?]
There IS an issue with central operating wells.
A good idea ....especally on paper....BUT...one should take into account the size, and number, of people who will occupy that central space at any one time?
[The NMRA actually tabulate aisle widths, as a guide.]
take into account there may be a need to be sitting...as standing up for long periods places a strain on folk.....
and 'sitting'....for example, bar-stool style.....takes up a remarkable amount of 'space'?
This CAN be mitigated somewhat, if one raises the overall height of the layout?
[layouts do look so much better if being viewed from around eye level, or just below......useful if one has issues about the OO track gauge?
Raising a layout to a more elevated height also has advantages regarding under-layout storage, furniture, workbenches, etc.]
I also have a 'liking' for an oval layout idea I first spotted in Scale Model Trains mag, years ago.........and Railstimulator's idea caused me to remember...the idea was.....if a 'central well' type layout wasn't feasible, then another way of achieving a similar effect is when stuck with a 'solid' table....to partition the baseboard down the centre...[or offset, or diagonal, choice is endless].......basically having two separate [scenically] layouts,each linked by the oval, continous run......I built one years ago, around 4 foot by 2 foot 6" rectangle, oval squeezed in, with a coalmine on a hillside on one side....with loading tracks, etc.....and a totally different scene on the other.....OK,so the sole loco was a small switcher, BUT.......operation was excellent as one had an originator, and a destination.....linked by as many laps of the oval as one wished.......but neither side could be seen from the other, from normal viewing angles.....[Heljan or Pola coal mine kit.....and if I recall, a quayside and tippler thing on the other.]