Complex sentence: In addition to the ferries, the Mersey Railway tunnel in 1886 and the Queensway road tunnel in 1934 gave rapid access to Liverpool, so opened up the Wirral Peninsula for development, and prompted further growth of Birkenhead as an industrial centre.
Split into simpler sentences: In addition to the ferries, the Mersey Railway tunnel in 1886 and the Queensway road tunnel in 1934 gave rapid access to Liverpool. This opened up the Wirral peninsula for development, and prompted further growth of Birkenhead as an industrial centre.