NZR OA class : Wikipedia, the free encyclopedia

NZR OA class

NZR O^A class

Oa class 2-8-0 steam locomotive NZR number 457

Type and origin
Power type	Steam
Builder	Baldwin Locomotive Works
Serial number	13908
Build date	1894

Specifications
Configuration:
• Whyte	2-8-0
Gauge	3 ft 6 in (1,067 mm)
Driver dia.	43 in (1.092 m)
Length	51 ft 8 in (15.75 m)
Adhesive weight	33.7 long tons (34.2 t; 37.7 short tons)
Total weight	57.4 long tons (58.3 t; 64.3 short tons)
Fuel type	Coal
Firebox:
• Grate area	16.7 sq ft (1.55 m²)
Boiler pressure	180 psi (1,241 kPa)
Heating surface	1,050 sq ft (98 m²)
Cylinders	four, Vauclain
High-pressure cylinder	11 in × 20 in (279 mm × 508 mm)
Low-pressure cylinder	18 in × 20 in (457 mm × 508 mm)

Performance figures
Tractive effort	13,175 lbf (58.61 kN)

Career
Operators	Wellington and Manawatu Railway, New Zealand Government Railways
Number in class	1
Numbers	WMR 13 NZR 457
Locale	Wellington - Longburn section
Disposition	Withdrawn

The O^A class is a solitary steam locomotive built by the Baldwin Locomotive Works for the Wellington and Manawatu Railway (WMR) in New Zealand. Ordered in 1894, it entered service in August of that year as No. 13 and was the first narrow gauge Vauclain compound in the world. In 1908, the WMR and its locomotive fleet were purchased by New Zealand Railways Department (NZR) and incorporated into the national rail network, and, although No. 13 bore a likeness to members of the O class, it was sufficiently different that it warranted separate classification. The designation of O^A was created and it was numbered O^A 457. It operated for another two decades until it was withdrawn in December 1929 in Auckland. The locomotive was known to WMR staff as "The Lady".^[1]

In 1896, a locomotive similar in appearance was ordered by the WMR, No. 16. Its technical specifications were such that when it was acquired by NZR it was classified separately and became the sole member of the O^C class.

References

^ Palmer & Stewart 1965, p. 92.

Bibliography

Palmer, A. N.; Stewart, W. W. (1965). Cavalcade of New Zealand Locomotives. Wellington: A H. & A W. Reed. ISBN 978-0-207-94500-7.
Stewart, W. W. (1974). When Steam was King. Wellington: A. H. & A. W. Reed Ltd. ISBN 978-0-589-00382-1.

External links

Drawing of an O^A/O^C class locomotive from Derek Brown

Rail vehicles of New Zealand

Diesel locomotives

Mainline	DA (inc. DAA, DAR) DB (inc. DBR) DC (inc. DCP) DF (English Electric) DF (General Motors) inc. DFT, DFB, DFM DG (inc. DH of 1956) DI DJ DL DM (on order) DQ and QR DX (inc. DXB, DXC, DXR)
Shunt	DE DH of 1978 DS DSA DSB DSC DSG DSJ TR

Electric locomotives

1500 V DC	E^A (later EO of 1968) E^C E^D E^O of 1923 E^W
25 kV AC	EF
Battery	E E^B

Diesel multiple units

Electric multiple units

1500 V DC (Wellington)	"English Electric" D^M (inc. D trailers) "Ganz Mavag" EM (inc. ET trailers) "Matangi" FP (inc. FT trailers)
25 kV AC (Auckland)	AM (inc. AMP, AMT, AMA)

Railcars

RM class	88 seater (also known as Fiats or twinsets) Clayton steam railcar Edison battery-electric railcar Red Terror railcar Midland railcar Leyland experimental petrol railcar McEwan Pratt petrol railcar Model T Ford railcar Sentinel-Cammell steam railcar Silver Fern railcar Standard railcar Thomas Transmission railcar Vulcan railcar Wairarapa railcar Westinghouse railcar
Others	A 88 Buckhurst petrol carriage