NZR A class (1873)

NZR A class (1873)
A67 at Ocean Beach Railway
Power type	Steam
Builder	Dübs & Co. (12), Yorkshire Engine Company (2)
Build date	1873 (12), 1875 (2)
Configuration	0-4-0T
Gauge	3 ft 6 in (1,067 mm)
Driver diameter	30 in (762 mm)
Wheelbase	5 ft 7 in (1.70 m)
Length	18 ft 0 in (5.49 m)
Locomotive weight	11 long tons (11 t)
Fuel type	Coal
Fuel capacity	0.4 long tons (0.41 t)
Water capacity	330 imperial gallons (1,500 l; 400 US gal)
Boiler pressure	120 psi (0.83 MPa)
Firegrate area	4.2 sq ft (0.39 m2)
Heating surface: Total	269 sq ft (25.0 m2)
Cylinders	Two, outside
Cylinder size	8 × 15 in (203 × 381 mm)
Tractive effort	3,072 lbf (13.7 kN)
Career	Public Works Department, NZGR
Number in class	14
Locale	New Zealand
Preserved	Four (62, 64, 66, 67)
Disposition	Four preserved, ten scrapped

The A class was the second class of steam locomotive (after 1872's F class) ordered to work on New Zealand's national railways. It should not be confused with the more numerous A class 4-6-2 tender locomotives of 1906. Initially ordered by the Public Works Department for use in the construction of lines, the A class was a small tank locomotive with a wheel arrangement of 0-4-0T. An initial twelve were constructed by Dübs & Co. in 1873 and two more were built in 1875 by the Yorkshire Engine Company. They were not just used by the Public Works Department; the New Zealand Government Railways also utilised the class to operate revenue services on smaller branch lines. None existed in government service by 1905, but their small size made them perfect for use on bush tramways and small private industrial sidings. Many members of the class survived for years in private use, and although all are now retired from commercial service, four have survived to be preserved by railway enthusiasts and two of the four are currently in full operational condition. One of these preserved locomotives, A 67, was the first in a cavalcade of locomotives at the celebration of the hundredth birthday of the Dunedin Railway Station.

A batch of A class engines, with differing external details was built at Wellington's Lion Foundry, by E.W. Mills Ltd in 1873, for use on the Foxton Section.

The term "Dido", as applying to New Zealand shunting locomotives, can be traced back to the small A class. Crew members from the ship Dido, moored at Bluff Harbour, in May, 1875 were looking for a night on the town, while in port. They took a small 4-wheeled rail trolley, and taking turns, both rode and pushed the trolley into Invercargill. When the southern enginemen saw the first A class locomotive arrive for use as a shunter, the name "Dido" was given as a nickname because of its diminutive size. Today, the term "Dido" is used to describe any small shunter on the NZR network.

Preservation

Dubs A class
A62 Anawhata Museum Trust, Whangarei
A64 Plains Vintage Railway, Tinwald
A66 Waimea Plains Railway, Mandeville, Southland
A67 Ocean Beach Railway, Dunedin

Mills A class
"Opossum" Shantytown Museum, Rutherglen
A 65 - Chassis Shantytown Museum, Rutherglen

External links

• Photo of an A Class loco at the opening of the Waimate Branch, 1877

References

• Heath, Eric, and Stott, Bob; Classic Steam Locomotives Of New Zealand, Grantham House, 1993
• "A class 0-4-0T". New Zealand Railways Steam Locomotives. http://www.trainweb.org/nzsteam/a_class.html. Retrieved 2008-05-29.