Task: Sentence Expansion
Input (English): The South Eastern and Chatham Railway ( SECR ) , was a working union of two neighbouring railways , the South Eastern Railway ( SER ) and London , Chatham and Dover Railway ( LCDR ) , which operated between London and south east England .
Output (English): The South Eastern and Chatham Railway Companies Joint Management Committee ( SE & CRCJMC ) , known as the South Eastern and Chatham Railway ( SE & CR ) , was a working union of two neighbouring rival railways , the South Eastern Railway ( SER ) and London , Chatham and Dover Railway ( LC & DR ) , which operated between London and south-east England .