NZR RM class

The RM class is the classification used by the New Zealand Railways Department (NZR) and its successors given to most railcars and railbuses that have operated on New Zealand's national rail network. As NZR and its successors has operated many diverse types of railcars, alternate names have been given to individual railcar classes. 'RM' stands for Rail Motor.

Experimental and early railcars

In the early 20th century, NZR began investigating railcar technology to provide profitable and efficient passenger services on regional routes and rural branch lines where carriage trains were not economic and "mixed" trains (passenger carriage/s attached to freight trains) were undesirably slow. However, due to New Zealand's rugged terrain and the 3 ft 6 in (1,067 mm) narrow gauge of the railway network, overseas technology could not simply be directly introduced. A number of experimental railcars and railbuses were developed.

NZR RM class (Standard)

The NZR RM class Standard railcars were a class of railcar operated by the New Zealand Railways Department in the North Island of New Zealand. Officially classified as RM like all other railcar classes in New Zealand, they acquired the designation of 'Standard' to differentiate them from others. They were introduced in 1938.

Background

Since the 1912 experiments with a MacEwan-Pratt petrol railcar, the New Zealand Railways Department had been seeking an effective and successful railcar design. Many routes simply did not have the demand to economically justify locomotive-hauled passenger express trains, so railcars were seen as a viable alternative. New Zealand's difficult terrain posed problems to railcar design, but in 1936, the Wairarapa railcars were introduced and proved to be a great success on the Wairarapa Line from Wellington over the Rimutaka Incline to the Wairarapa, and following from this, the Standard railcars were designed to provide regional services in on regular lines in the North Island.

NZR RM class (88 seater)

The NZR RM class 88-seaters were a class of railcar used in New Zealand, known unofficially as 'articulateds', 'twinsets', 'Drewrys' and 'Fiats'. They were purchased to replace steam-hauled provincial passenger trains and mixed trains. New Zealand Government Railways (NZR) classed them RM (Rail Motor), the notation used for all railcars, numbering the 35 sets from RM100 to RM134.

History

NZR RM class (Edison battery-electric)

The NZR RM class Edison battery-electric railcar was a popular and successful railcar that ran in Canterbury, New Zealand for eight years. The prototype, RM 6, was arguably the first successful railcar in New Zealand, but the type was not developed into a class.

The railcar had a wheel arrangement of Bo-Bo under the UIC classification system, weighed 32 tonnes (31 long tons; 35 short tons), had driving controls at each end, and with an engine output of 90 kW (120 hp), it travelled comfortably at 60 km/h (37 mph). In appearance, it looked like a cross between a regular railway passenger carriage and a tram; side-on, it looked like a passenger carriage, but each end resembled the front of a tram from that era. The body was built by Boon & Stevens, the noted tram-car builders of Christchurch, in 1926, and equipped with Edison battery-electric equipment.

Capable of carrying about 70 passengers, with 60 seated, and a separate smoking compartment, the railcar had a range of about 100 miles (160 km) on one battery (charge). Apparently a layover of about 4 hours was needed to recharge the battery. When introduced the railcar was billed as capable of being used on the Christchurch-Little River and Christchurch-Rangiora runs as well as being available for charters to other North Canterbury destinations. Being electrically powered and running on a storage battery, the railcar was very quiet, with the only wheel noise being noticeable when in motion.