Instructions: In this task, we ask you to elaborate the sentence without changing its general meaning. You can do so by explaining further the input sentence, using more precise wording, adding qualifiers and auxiliary information etc.
Input: 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:
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 .