The Rail Accident Investigation Branch (RAIB) has published it's report into a near miss at Chalfont & Latimer station which occurred on 21st June last year and it makes interesting, if not a little scary, reading.
Chalfont & Latimer station is a London Underground station, which is shared by Metropolitan Line (underground) & Chiltern Railways (overground) services.
The incident involved a Chiltern Railways train heading towards London Marylebone which passed a signal at danger (SPAD) which protected the junction for the Chesham Branch, triggering an automatic emergency brake application. The driver had missed the red signal and, thinking that the emergency brake application was "spurious", he reset the tripcock to release the brakes and carried on towards Chalfont & Latimer station, passing through (and damaging) the junction points, only realising that there was a problem when the train lurched to the right, taking the crossover at 10mph over the permitted speed. At this point he made a full emergency brake application, coming to a stand around 23 metres in front of a Chesham-bound Metropolitan Line train which was stationary in the platform.
https://assets.publishing.service.go...___Latimer.pdf
Tony