A puzzeltask

[SMcNeill]

Around here, the tracks tend to look like this:

------------------\------------------------/-----------------------
                     -------------------------

Now, with the side rail on an offset, two trains can pass each other, or an engine can detach from one end and attach itself to the other end.  It tends to use less room overall, I think (since the railway has to maintain X feet to either side of a track), so it's this type of junction or switchback that we tend to see around my neck of the woods.