14-04-2014, 06:24 AM
In my opinion:
Calling 127N would prevent valid parallel moves between the departure and shunting lines;
148R would prevent valid parallel moves in and out of the spur;
Similarly calling 137R prevents moves along the down main to/from platform 3.
Obviously there is a balance required between setting every possible set of points to the most protective lie, and locking up the junction so parallel moves can't take place.
Calling 127N would prevent valid parallel moves between the departure and shunting lines;
148R would prevent valid parallel moves in and out of the spur;
Similarly calling 137R prevents moves along the down main to/from platform 3.
Obviously there is a balance required between setting every possible set of points to the most protective lie, and locking up the junction so parallel moves can't take place.