I would love the full south western mainline down to Portsmouth Harbour, (maybe even via Southampton) but knowing dovetail and it’s probably too long for TSW. So instead, I’d like to propose a branches type route, with one line going from London Waterloo to Guildford through the mainline and also through Effingham Junction, the line to Hampton Court, and also either a line to Windsor & Eton Riverside or Reading, or either the Hounslow or Kingston loop. (preferably both but we would probably only get one) This route would be based in the present day, with locos such as the Class 159, Class 450, Class 444, and Class 455. I get licensing may be an issue but hopefully now it has fallen under public ownership there could be another chance to get a license.
What about the Chessington South branch? It would be a complete travesty to not include it. Otherwise a good suggestion. A little more detail would be useful for those unfamiliar to the,area. Remember that suggestions are trying to sell themselves to players and developers by listing things like service patterns, history, landmarks, train types, etc, etc.
Chessington south be perfect as there first route its only like 45 or 50 mins long it be perfect starter to bring 455 and 450
