You could avoid the duckunders (save arthritic knees) and get broader curves if you them, by going around the walls instead of an island layout with acess hatches. build the whole thing 30 inches wide (or however far you can reach) around the outside of the room and maybe a peninsula up the middle if you have enough room. 24 inch aisles are wide enough for one guy operation. 30 or more if multiple operators.