CPR Hudsons
Chugalug - re your 5701, it's the immediate forerunner of the CPR Royal Hudson class and is numbered in the same series commencing 2800; mechanically very similar to its successor, which aside from a semi-streamlined appearance differed only in some minor details such as a slightly increased boiler pressure.
The CPR today maintains one of these earlier specimens in running order, and it occasionally ventures out on to the main line. They seem to have noticed how Union Pacific gains much from its policy of always having had (from Day 1, no less) at least one working steamer on its roster, and UP is now restoring a 'Big Boy' (arguably the world's largest ever steam loco) to operating condition; now that will indeed be something to see - and hear!