Canadian National Railways
'U4' class 4-8-4

Built by the Montreal Locomotive Works and the Canadian Locomotive Works 1927-1944

CYLINDERS (2) 24 ins x 30 ins (610mm x 762 mm)
COUPLED WHEEL DIAMETER 77 ins (1,956mm)
TOTAL HEATING SURFACE
(including superheater) 5,391 square feet (500.8m2)
GRATE AREA 73.7 square feet (6.8m2)
BOILER PRESSURE 275 PSI (1,896 kpa)
TRACTIVE EFFORT 52,457 lbs (23,794kg)
TOTAL WEIGHT 300 tons (304.8 tonnes)
LENGTH OVERALL 95 feet 1 in (28,981mm)

In the period between the Great Wars the 4-8-4 'Northern' as it was commonly known became the definitive front-line passenger locomotive on the North American Continent.

Canadian National Railways certainly was at the forefront of this trend. First introduced in 1927 as the 'U2' 'Confederation' type improved and updated 'U3' and 'U4' classes followed until the last batch was completed in 1944. By this time over two hundred of these majestic machines had been delivered to Canadian National and its subsidiary companies. 'U4' class number 6400 was one of eleven semi-streamlined versions that entered service between 1936 and 1938; they differed from the other class members by having slightly smaller cylinders and larger 77 ins (1,956mm) as compared to 73 ins (1,854mm) driving wheels.

In keeping with common CN practice Vanderbilt cylindrical tenders were employed and up until 1936 another distinctive feature was a transverse feed water heater placed immediately in front of the stack. By 1960 all of the locos were retired but a couple were retained for posterity. Number 6400 is one of these and proudly resides at the Ottawa Museum of Science and Technology. This grand locomotive is a worthy example of a breed that transversed vast distances and conquered the formidable grades of the continental divide hauling the nations lifeblood.