Ahh no! they've replaced the character-laden rickety old wooden bridge across the Cass River with this clean and functional item. DCs 4513 + 4761 head west with a decent off-season train of seven cars and two vans - the middle one is an open-air observation car with HEP in the middle, the rear is primarily for luggage with a small viewing platform at the train-end. As the weather can be great or miserable all year round (and often all of that several times a day) I'd pass on the longer summer days and see some snow on the mountains if I were you.
Trains on 3' 6" (1.067m) track from Whangarei to Bluff with virtually heritage rebuilt EMD and GE locomotives still the mainstay power. The network was privatized in 1990's and operated by Toll until 2008 when state owned KiwiRail was established.