Members of the Pahiatua Railcar Society were hard at work on Friday replacing an engine in the RM31 railcar.
Built in 1938 in the Hutt Railway Workshops, the RM31 was one of six of its type made, and is the only one of the surviving four still certified to run on the main line.
The Pahiatua Railcar Society preserved the railcar and it is housed in their purpose-built storage shed and workshop located at the railway station at Mangamutu.
On Friday, two cranes lifted the railcar and four society members fitted it with a reconditioned engine.
Steve Jones, society member and project manager, said it was the biggest job ever done on a standard railcar outside of a major railway workshop in New Zealand.