Complex sentence: A difficult hillside climb out of Dunedin was encountered with construction taking a significant length of time, and for this reason, the line from Dunedin met that advancing south from Oamaru at Goodwood, some 310 kilometres south of Christchurch but only 57 kilometres north of Dunedin.
Split into simpler sentences: A difficult hillside climb out of Dunedin was encountered, with construction taking a significant length of time. For this reason, the line from Dunedin met that advancing south from Oamaru at Goodwood, some 310 kilometres south of Christchurch but only 57 kilometres north of Dunedin.