Complex sentence: The line was opened temporarily in 1860, under the South Wales Railway; and was fully opened the following year, operated by the Carmarthen and Cardigan Railway, operating between Carmarthen and Cynwyl Elfed.
Split into simpler sentences: The line was opened temporarily in 1860, under the South Wales Railway and was fully opened the following year. It was operated by the Carmarthen and Cardigan Railway between Carmarthen and Cynwyl Elfed.