Complex sentence: In the 1950s there was a'camping coach' at the station; an early form of self-catering accommodation which used converted redundant railway carriages for occupation by holiday makers who could arrive and depart by train.
Split into simpler sentences: In the 1950s there was a'camping coach' at the station. These were an early form of self-catering accommodation being converted redundant railway carriages converted for occupation by holiday makers who could arrive (and depart) by train.