NZR OC class

{{Short description|New Zealand steam locomotive}}

{{Use New Zealand English|date=July 2024}}

{{Use dmy dates|date=July 2019}}

{{DISPLAYTITLE:NZR O^C class}}

{{Infobox locomotive

|name = NZR O^C class

|powertype = Steam

|image = Oc Class steam locomotive NZR 458, 2-8-0 type. ATLIB 276930.png

|caption = O^C class 2-8-0 steam locomotive NZR number 458

|builddate = 1896

|builder = Baldwin Locomotive Works

|serialnumber = 15055

|whytetype = 2-8-0

|uicclass = 1'D

|gauge = {{Track gauge|42in|lk=on}}

|locotenderweight = {{convert|62.8|LT|t ST|abbr=on}}

| weightondrivers = {{convert|36.7|LT|t ST|abbr=on}}

|length = {{convert|51|ft|8|in|2|abbr=on}}

|boilerpressure = {{convert|200|psi|kPa|0|abbr=on}}

|tractiveeffort = {{convert|15110|lbf|kN|2|abbr=on}}

| firearea = {{convert|16.7|sqft|m2|abbr=on}}

| totalsurface = {{convert|1050|sqft|m2|abbr=on}}

| hpcylindersize = {{convert|11|x|20|in|mm|0|abbr=on}}

| lpcylindersize = {{convert|18|x|20|in|mm|0|abbr=on}}

|operator = Wellington and Manawatu Railway
New Zealand Railways Department

|fleetnumbers = WMR 16
NZR 458

|numinclass = 1

|retiredate = July 1930

}}

The O^C class, built by the Baldwin Locomotive Works for the Wellington and Manawatu Railway (WMR) in New Zealand, consists of a solitary steam locomotive. Ordered in 1896 as an externally similar but more powerful version of the O^A class locomotive ordered in 1894, it entered service in June 1897 as No. 16. It was a Vauclain compound locomotive.{{sfn|Palmer|Stewart|1965|p=94}}

In 1908, the WMR and its locomotive fleet was purchased by the New Zealand Railways Department (NZR) and incorporated into the national rail network, and although No. 16 bore a likeness to members of the O class, it was sufficiently different that it warranted separate classification. Technical differences were sufficient that it was not classified with the visually similar WMR No. 13/NZR O^A 457, and it became O^C 458. It is known to have operated on the line from the Hutt Valley through the Rimutaka Range to the western end of the Rimutaka Incline, and its final depot was at Cross Creek at the eastern end of the Rimutaka Incline in the Wairarapa. It was withdrawn from service in July 1930.