"mmellor" wrote

Coulsdon North was always off the fast (Quarry) line - the 1980s
changes didn't alter tracks in that area. What they did do was
rationalise the arrangements between S. Croydon & Windmill
Bridge/Gloucester Rd.

I'm not sure that's quite right. IIRC the local lines ran on the west side
of the formation from Windmill Bridge Junction right through to Coulsdon
North. The Quarry Lines took off from the Through Lines at Stoats Nest (just
north of Coulsdon), but it was possible for trains to run into and out of
Coulsdon North on the Local Lines without conflicting with trains running
between the Through Lines and the Quarry Lines.

I thought Coulsdon N closed because Smitham (next door) could perform
its functions very adequately.

When the track rationalisation was carried out, it was much easier for local
trains on the Slow Lines on the east of the formation to reach Smitham than
it would have been for them to get to Coulsdon North.

Peter