NZR G Class Garratt Pack

The NZR G class was the only type of Garratt to be used by New Zealand Railways (NZR), and were used to deal with traffic and banker locos on the steep grades of the NIMT (North Island Main Trunk). They were built in 1928 and got used up until 1931. The G Class were mostly based at Ohakune and operated between Taihape and Ohakune on the NIMT. Trainloads were reduced and this defeated the purpose for which the Garratts were purchased. Due to the troubles faced with the Garratts in their original form, a proposal was put forward in late 1935 for the three Garratts to be dismantled and the engine units used to build six new 4-6-2 tender locomotives. The three locomotives were dismantled at Hutt Workshops in 1936 and the engine units shipped to Hillside Workshops in Dunedin for eventual rebuilding. The engines as rebuilt were fitted with a new third cylinder, a modified AB class boiler, a new cab and trailing truck based on those used on the Baldwin AA class. The First rebuilt G class was outshopped in 1937, with the last one being outshopped in 1938.