Complex sentence: Recently the railway has pushed for a main line connection to the Bittern Line, a crossing to the line would mean 12 crossing or so a year, bringing in Tours and visiting engines to the railway that can't be brought in by road.
Split into simpler sentences: Recently the railway has pushed for a main line connection to the Bittern Line. A crossing to the line would mean twelve crossings or so a year, bringing in tours and visiting engines to the railway that cannot be brought in by road.