In the more than 30 odd years of my "real world" railway experience, Mark, I have to admit that I have never come across the term "Schoolmistress" (or "Stationmistress" for that matter), used in relation to the 'design' of railway yard ladders ("coming across" stocking ladders, on the other hand, has been common place). Perhaps you could enlighten us all in this regard. Given that which 'RailPilgrim' has provided, a not so quick Google search resulted in the locating of this forum thread, which, although not being a tutorial in the strictest sense of the word, may also shed some light on your requirements...
OMG my so bad, I did indeed mean station mistress, I must have had other things in my mind (wink).
thanx all for the input and thanx railpilgrim for the link.
I like using fixed track turnouts to set up yard ladders, and you later on replace all the fixed track turnouts, one by one, with regular track splines