Complex sentence: The Stanhope to Annfield section was losing money, so the insolvent railway company was dissolved on 5 February 1841 and the northern section became the Pontop and South Shields Railway.
Split into simpler sentences: The Stanhope to Annfield section was losing money and the insolvent railway company was dissolved on 5 February 1841. The northern section became the Pontop and South Shields Railway.