Complex sentence: The southbound service departed Auckland at 8:20am and reached Tauranga 3 hours 31 minutes later at 11:51am, northbound from Tauranga at 1:05pm to Auckland at 4:34pm, 3 hours 29 minutes later.
Split into simpler sentences: The southbound service departed Auckland at 8:20am and reached Tauranga 3 hours 31 minutes later at 11:51am. The northbound service left Tauranga at 1:05pm and reached Auckland at 4:34pm, 3 hours 29 minutes later.