| NZR OA class | |
|---|---|
| Power type | Steam |
| Builder | Baldwin Locomotive Works |
| Serial number | 13908 |
| Build date | 1894 |
| Configuration | 2-8-0 |
| Gauge | 3 ft 6 in (1,067 mm) |
| Length | 51 ft 8 in (15.75 m) |
| Locomotive & tender combined weight |
57.4 long tons (58.3 t) |
| Fuel type | Coal |
| Boiler pressure | 180 psi (1.2 MPa) |
| Tractive effort | 15,177 lbf (67.51 kN) |
| Career | Wellington and Manawatu Railway, New Zealand Government Railways |
| Number in class | 1 |
| Number | WMR 13 NZR 457 |
| Locale | Wellington - Longburn section |
| Disposition | Withdrawn |
The OA class, built by the Baldwin Locomotive Works for the Wellington and Manawatu Railway (WMR) in New Zealand, consisted of a solitary steam locomotive. 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 to warrant separate classification. Accordingly, the designation of OA was created and it was numbered OA 457. It operated for another two decades until it was withdrawn in December 1929 in Auckland. The locomotive was known to Manawatu men as The Lady.
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 OC class.
