some old local articles

it was built at the hutt workshops in 1935. chances are some designs would have been mimicked from overseas, though scaled down quite a bit. im guessing we imported some engines very early on, otherwise how would the guys have learned how to build them?

https://en.wikipedia.org/wiki/NZR_K_class_(1932)

Well don't forget at one point you were a colony or overseas territory so I would almost put money on it that the initial railways were imported by us and built there like they were in most commonwealth (i.e. ex empire) nations