New Zealand Railways RM 6

The RM 6 of the New Zealand Railways was a single battery-powered railcar built in 1926 by Boon & Stevens. It was designed to speed up passenger traffic on lines where mixed trains with passenger and freight cars were in operation, which were very slow due to the constant loading and unloading of goods. The idea came from former NZR employee Ambrose Reeves Harris, who was now working for the Edison company. In the previous years, battery locomotives of the classes E and E^B had already been built.

The car was around 55 feet in length and seated 60 passengers. Each of the four axles had a 30 hp traction motor and the batteries supplied by Edison were good for a range of about 100 miles. When completely empty, they could be recharged in seven hours. The car was used in the Christchurch area on the Lyttelton Line that had a 1.6-mile tunnel. When this line was electrified, it came to another line in the same area. After only eight years of service, it was destroyed in a depot fire in Christchurch in 1934. No additional cars were built since the cost was more than three times that of a Sentinel-Cammell steam railcar.