All the London railway stations :
Chafford Hundred is a station on the C2C Fenchurch Street line, and is deemed to be accessible. See pictures and further accessible transport in London detail from links below.
National Rail lines : The Station is on the C2C line from Fenchurch Street and runs via Barking, and Upminster.
Accessibility friendly : Yes, allegedly.
General description : See wiki
More comment : National Rail Map & Guide, the station has 5 disabled parking spaces.