I knew the line in the 1970s, when it was worked by a pair of 2EPBs. It had its own bay at West Croydon (Plat 2?) and from there I think there was double track as far as sidings near Waddon Marsh for a former gasworks and power station. There was also double track from Mitcham Junction (briefly sharing the main line to Sutton etc through the station), through Mitcham Station, and as far as its goods yard on the Wimbledon side of the station. There was a final double stretch into Wimbledon from Merton Park, where the line from Tooting (by then shortened to the Triang factory for freight) joined in. The two trains in service would pass anywhere between Mitcham Junction and Mitcham. At Wimbledon they usually used Platform 10, then shared with the Tooting-Wimbledon-Sutton down line. Being an ex-LBSC line, Wimbledon was Down despite being north-west of Croydon, closer to London.
Mitcham Junction is more-or less surrounded by Mitcham Common and for me and most people only useful as an interchange with the Sutton Line. There was/is a nearby golf course.
I am not sure where the single line tokens were handled, other than at Mitcham signal box (at the Down end of the Down platform) until the line here was singled back a few hundred yards in the Croydon direction, leaving Mitcham's Up platform disused. This was because a retaining wall just past the station and the road over-bridge, in the Wimbledon direction, had begun to collapse and needed heavy bracing placed in the Up 4ft way - still there today I believe with the tram lines inter-laced past them.
Mitcham was the principal intermediate station with a sizeable goods yard that closed in the 1960s. The passenger station was entered from the road via a tunnel-like passage through the centre of a large Georgian house. I believe it was once a merchant's house and the passage was for carts to access a yard behind. At the time I knew, the railway seemed to own the house but rented it as flats. The station offices and booking window were behind the house in a low building with creaking floorboards, and led out to the upper level of the footbridge with steps down to the two platforms.
The line is in a shallow cutting at Mitcham, passing under London Road. From Croydon to Mitcham the LBSC had mostly built it on the trackbed of the old horse-drawn Surrey Iron Railway. The SIR crossed London Road Mitcham with a level crossing but the LBSC seem to have raised the road and lowered the railway here to make the bridge - and the problematic retaining wall. The SIR turned away northwards to Wandsworth about where the retaining wall ends.
Merton Park seemed to attract a fair amount of passengers, being near a school, and in a residential and minor shopping area. Its buildings and a platform were on the once double-track curving line to Tooting, and a triangular platform was between that and the straight single Croydon-Wimbledon line. Passengers for the latter (which was all of them by long before 1970) walked down the platform end-ramps and across the Tooting line on a board crossing. H&S would have a fit these days; I believe the Tooting line only had one freight train per week by then. After the Triang freight ceased, part of the Tooting line between the platforms was filled in with rubble and earth, and a path made over it.
The other stations on the line were virtually or actually halts.
Two pictures showing Mitcham Station around 1970. One is a view from across London Road, showing the entrance passageway through the centre of a Georgian house, and the other is of the ticket office exterior viewed from the footbridge and also showing the rear of the Georgian house.
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