Connecting Shoeburyness to Fenchurch Street via Basildon, Upminster and West Ham with a loop line via Grays. Will include the class 357 Electrostar, which can recycle sounds from the Class 377, The class 720 Aventra could also be used using similar model from the class 710. The class 66 can also be used as freight AI/player from Grays to Barking as this is frequently used for freight trains. This line would be a quieter line into London as not much other traffic comes into Fenchurch Streets platforms, only c2c. The scenery would also be a good range as it runs along side with the Thames Estuary between Leigh-on-Sea and Chalkwell, running along side the District line from East Ham to Upminster (H&C to Barking). AI LO trains from Barking as the GOBLIN will be released soon. The map below shows the whole line, it will be a decent size for the game (ignore the limited services in black to Stratford and Liverpool Street)
Seconded, either as a current route or set in the 1950s bringing Tilbury Riverside station into play. The only addition I feel must be added to the OPs comments are London Gateway port & the Port of Tilbury to be included, utlising the Class 66 on container trains. Class 66 locos have a stabling point within London Gateway port itself, close to the railhead where containers are loaded & discharged. An excellent suggestion for such an interesting line with a lot of operationall possibilities.
I put up my own post about this 1 thought I didn't think of including 66 Freight service, so well done for that. The only thing I would suggest is 1. 720 is not really nesacery as they are simply booster units to lengthen peak services. Also, the freight services could finish up at Dagenham Dock sidings.
I like the idea of the C2C. I enjoyed exploring the other post by Remy Nicholls which was highly detailed
