Minimum aisle/access space vs design

Pat, I think 18" is a little snug for isleways. I am going to try to keep mine 24" minimum. Try this example out....  take two kitchen chairs, with the backs facining each other at 18" and try to walk through it, and try to turn around between them. its tighter than you think or how it looks.  I know myself, I'm not getting any younger or thinner for that matter

Ryan

Very subjective.  From your sketch I do not believe you mean an aisle but rather a pinch point.  I have one pinch point of 16" at a height of 42" that lightly ouches my fabric as I pass.  Your milage may vary.

An access aisle minimum of 24" is good in most cases.  36" is OK for operators to pass.  

However a venturi / pinch point can be made  to just basicly allow movement if that serves the RR design purpose. 

On my old garage layout I had a 15" wide "pinch point" at 48" high (lower left corner), the entrance was on the left side:

Overall it was not a problem, I did very little standing in that area.  I should have moved the door from the left side to the bottom center (just left of the yard), it would have given me more track space on the left (to make the curve bigger) and done away with the pinch point.  At 48" high it was not a problem for me to squeeze thru (I am or was 5'-10" tall).

Have a 24" pinch point on my layout, otherwise 30" minimum for aisles

Bruce

I am in the 30" camp myself, wider is better when you have the real estate to work with.

If you are the only one that uses the train room then just about any of the dimensions listed above will work.  Now if you 'share' the train room with  . . .  then that must be part of the 'pinch point' equation, and it has nothing to do with Oreos!   I have done small layouts with 24 inch pinch points but on larger layouts where there will be multiple operators 30 to 36 inches is the norm.  However all of this is tempered by the available space to accomplish your railroad design.  Additionally part of the problem with narrow pinch points its very, very hard to protect the trains, scenery, etc,. 

OK that's my 2c for this evening, bottomline its your layout, design it to maximize your fun time.  Russ

Knowing that most people advise having aisles of 30"-36", I built my layout with one aisle that has only 24" because 99.5% of the time, I am the only one down there running trains.  When ever I do have a guest, we can take turns to pass each other.

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Dennis

I ran an 18 aisle on my last layout, to conserve layout space. Never again. New layout has 24-inch minimum space around. What I lost I layout space I made up for in ease of use

The a narrow pinch point my be easier to deal with than an narrow asile.

Probably will depend on how often you use it 

Pat, your plan for a 12'x 12' room has potential to be adapted for wider curves and wider aisles. This quicky modification is schematically similar. Take your time to consider more possibilities.

Hey Ace:

That is one nice modification you were kind enough to design. I may incorporate some parts into the "master plan" for my new layout. The key for me is reverse loops and passing sidings. They make it so much more interesting.

My new train room is 11 x 19, I'm thinking the layout will be 7x15 with possible yard expansion (read hole in the wall) into the storage area adjoining this room.

Anyway, cool design.

All the best,

Paul