The Canadian High-Pressure Locomotive.
Left: The CPR 2-10-4 compound locomotive of 1931. No 8000.
The Schmidt High-pressure System used a closed-circuit of steam and distilled water working at 1,350 psi, transferring heat to an HP boiler working at 850 psi pressure to supply the center cylinder. The exhaust steam from this was mixed with 250 psi pressure steam from the LP boiler to feed the two outside cylinders.
The locomotive was built by Angus Shops in 1931 and was the Canadian Pacific's heaviest steam locomotive. It operated on the Mountain Subdivision of the CPR from 1931 to 1936, but was scrapped in 1940.
In the USA the 2-10-4 wheel configuration was called the "Texas" type, but the CPR used the term "Selkirks" after the range of the Rockie mountains that the Railway crossed.