The line diverges from the Southeastern Main Line at Lewisham Vale junction at the country end of St John 's station at the edge of Inner London .
The line runs as far as Rochester Bridge junction beside the River Medway by the north coast of historic mid-Kent .
The line diverges from the Southeastern Main Line at Lewisham Vale junction at the country end of St John 's station at the edge of Inner London , and runs as far as Rochester Bridge junction beside the River Medway by the north coast of historic mid-Kent .