the line was started in 1951, but in march 1953 it was decided to build the mill at kawerau not murupara, because kawerau had cheap geothermal steam for energy and also as the climate of murupara had winter mist and fog so was less suitable for a large town. so the branch ran via kawerau to murupara rather than directly from hawkens junction near edgecombe. the kawerau to murupara section required major earthworks to limit the ruling grade against loaded log trains to 1 in 60. however the easy grades between kawerau and the port of mt maunganui allow very long trains of over 2,000 tonnes.