Complex sentence: A short extension from Middlesbrough to Redcar, the line branched off the existing S&DR line before the existing Middlesbrough terminus, and this was closed and a new through station opened with the line to Redcar on 4 June 1846.
Split into simpler sentences: A short extension from Middlesbrough to Redcar, the line branched off the existing S&DR line before the existing Middlesbrough terminus. This was closed and a new through station opened with the line to Redcar on 4 June 1846.