Commonwealth Railways CN class

{{Short description|Class of former CN H-6-c locomotives}}

{{one source|date=July 2016}}

{{Use Australian English|date=May 2014}}

{{Use dmy dates|date=May 2014}}

{{Infobox locomotive

|name = Commonwealth Railways CN class

|powertype = Steam

|image = CN76, Port Pirie, 1951(1).jpg

|alt =

|caption = CN76 at Port Pirie Junction station in 1951

|designer =

|builder = Montreal Locomotive Works

|ordernumber =

|serialnumber =

|buildmodel =

|builddate = 1907-1908

|totalproduction = 8

|rebuilder =

|rebuilddate =

|numberrebuilt =

|whytetype = {{whyte|4-6-0}}

|uicclass =

|gauge = {{RailGauge|1435 mm|allk=on}}

|leadingdiameter =

|driverdiameter =

|trailingdiameter =

|minimumcurve =

|wheelbase =

|length =

|width =

|height =

|axleload =

|weightondrivers =

|locoweight =

|tenderweight =

|locotenderweight =

|tendertype =

|fueltype = Coal

|fuelcap =

|watercap =

|tendercap =

|sandcap =

|boiler =

|boilerpressure =

|feedwaterheater =

|firearea =

|tubearea =

|fluearea =

|tubesandflues =

|fireboxarea =

|totalsurface =

|superheatertype =

|superheaterarea =

|cylindercount =

|cylindersize =

|frontcylindersize=

|rearcylindersize =

|hpcylindersize =

|lpcylindersize =

|valvegear =

|valvetype =

|valvetravel =

|valvelap =

|valvelead =

|transmission =

|maxspeed =

|poweroutput =

|tractiveeffort =

|factorofadhesion =

|trainheating =

|locobrakes =

|locobrakeforce =

|trainbrakes =

|safety =

|operator = Commonwealth Railways

|operatorclass =

|powerclass =

|numinclass =

|fleetnumbers = CN70-CN77

|officialname =

|nicknames =

|axleloadclass =

|locale =

|deliverydate =

|firstrundate = November 1942

|lastrundate =

|retiredate =

|withdrawndate = April 1952

|preservedunits =

|restoredate =

|scrapdate =

|currentowner =

|disposition = All scrapped

}}

The Commonwealth Railways CN class was a class of {{whyte|4-6-0}} steam locomotives purchased by the Commonwealth Railways, Australia, from the Canadian National Railway (CN) during World War II, for use on the Trans-Australian Railway.

The eight locomotives in the class had been built in 1907-1908 by Montreal Locomotive Works, Montreal, Quebec, for the Canadian Northern Railway. After passing into CN ownership in 1918, they became part of CN's H6c class.{{FluMarWil-LocRailCR|pages=42–43}}