Better informed heads than mine may be able to tell me the reason...
Having another look ...
(Thank you , Mark Bau)
The next thing that bothered me was the fact that both Cathkin and Alexandra stations were on the aisle (South) side of the layout.I didn't fancy the idea of looking over the top of them. So the decision was made to transfer both stations to the North of the line . In the case of Cathkin, I flipped the whole yard around. putting the goods shed onto the stub track. I also deleted Nr.3 road.
Cathkin diagram source: Mark Bau
Theory is a wonderful thing, but all this would have to be turned into reality.-