Complex sentence: The Hull & Selby Railway received permission in June 1836 to complete the line to Hull, and the line, which crossed the Ouse at Selby with a bascule bridge, opened on 1 July 1840.
Split into simpler sentences: The Hull & Selby Railway was formed to complete the line to Hull, and received permission "when". The line, which crossed the Ouse at Selby with a bascule bridge, was opened on 1 July 1840.