Canadian National / Grand Trunk Western 4-8-2 Locomotives in Canada

Class U-1-f (Locobase 197)

Data from tables in 1947 Locomotive Cyclopedia, substantially supplemented by CN to 1953 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange. (Many thanks to Chris Hohl for his 22 September 2017 email reporting unlikely boiler pressure values for 177 entries. A Locobase macro caused the error .) Works numbers were 72757-72776 in 1944.

Last in a series of U-1 4-8-2s. The earlier series were:

U-1a 16 Canadian Loco 1923 6000-6015 (Locobase 7333)

U-1b 21 same 1924 6016-6036 (Locobase 7333, Locobase 7334)

U-1c 5 Baldwin 1925 6037-6041 (had 26-in diameter pistons, 210-lb BP, 9,600-lb TE, combustion chamber 36 1/2 in long, 22.75 between tube sheets.)

U-1d 5 Canadian 1929 6042-6046

U-1e 12 Montreal 1930 6047-6058

The U-1fs were updates of this design delivered 14 years later. The biggest improvement was the cast steel frame; almost as useful was the exhaust steam injector. The boiler layout took on a Superpower look as well, with the small tubes reduced to a handful and the larger flues dominating the vessel. The website for the 6060, a restored U-1-f -- [], accessed 16 September 2007 -- gives a detailed description of the development considerations for this class:

"Dimensionally similar,the U-1-f class was a far cry from the U-1-a in mechanical and cosmetic details. The new locomotives were built on and around a one piece cast frame, made by General Steel Castings, which included the pilot, cylinder and valve block and hefty mounting brackets for the air compressor and exhaust steam injector."

Diagram details include the 12" (305 mm) piston valves and the use of thermic syphons to supplement the firebox heating surface area.

The 6060 website peeks under the boiler lagging as well:

"Considerable design work had gone into the 'internal' streamlining of the 6060's. Tests, experiments and the experience of other railways had proven conclusively that if the steam flow from boiler to cylinders to smokestack was along a smooth and gently curved and totally unrestricted passage, then the engineer could anticipate reduced back pressure, swifter throttle response and reduced fuel consumption."

There was more innovation, according to the account. To reduce stress on the rail and on the frame, the class used a "complex" suspension setup that virtually eliminated nosing and allowed reduced counterbalancing. Although equipped with relatively small 73" drivers, which incidentally suited the class well for fast-freight duties, the engines were able hit very high speeds as passenger haulers. One account gives a 125-mph top speed, although one suspects that wasn't officially timed.

The engine was colorfully trimmed and graceful in appearance, with a blunted cap covering the smokebox door. This feature inspired the nickname "Bullet-Nosed Betty".

Tender capacities are shown for the oil-burning group, which consisted of 6060-6062, 6066-6067, 6073-6075. The coal burners trailed tenders carrying 18 tons of coal and 11,700 gallons of water. These were 6063-6064, 6068-6071, 6076-6079.

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Class U-1a/U-1b - Robinson (Locobase 7333)

Data from CN to 1953 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange. "Mountain Type Locomotives--Canadian National Railways", Volume 29, No 8 (August 1923), pp. 20-22. Works numbers were 1696-1711 (1923) and 1764-1769 (1924).

The CLC supplied 37 Mountains to the CN in two years. A majority was fitted with the Robinson superheater while others, shown in Locobase 7334, had Schmidt Type A superheaters. The Robinson engines that appear in this entry held steam in the superheater at all times during operation (many earlier engines using the Schmidt design used dampers to close the flues in certain conditions). The difference was "calculated to lengthen the life of the units."

All had the 14" (356 mm) piston valves that would be standard on these 4-8-2s, but unlike later sub-classes, U-1a and U-1b engines did not have thermic syphons. A later CN diagram shows that the Robinson superheaters were replaced by the Schmidt design - the diagram's superheater surface area difference did not change, however.

With a few exceptions, the entire class remained on the CN roster until the late 1950s-early 1960s before

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Class U-1b - Schmidt (Locobase 7334)

Data from CN to 1953 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange. Works numbers were 1744-1758 in 1924

The CLC supplied 37 Mountains to the CN in two years. A majority was fitted with the Robinson superheater; these are shown in Locobase 7333. This clutch of 15 supplied by the CLC in 1924 used Schmidt Type A superheaters that added more surface area.

All had the 14" (356 mm) piston valves that would be standard on these 4-8-2s, but unlike later sub-classes, U-1a and U-1b engines did not have thermic syphons. One oddity in the diagrams is that the firebox is shown with the 4-ft-long (1,219 mm) combustion chamber, but the longer tubes and flues.

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Class U-1c (Locobase 5303)

Data from Steamtown's Special History Study of 6039 -- [] (visited 4 Jan 2003) and DeGolyer, Volume 76, pp.334+. Works numbers were 58436-58437, 58463-58465.

Firebox heating surface area included 27 sq ft (2.5 sq m) in four arch tubes and 74 sq ft (6.85 sq m) in the combustion chamber. The latter was a foot shorter than those in the CLC U-1a and1bs (Locobases 7333-7334). Piston valves measured 14" (356 mm) in diameter.

Much of boiler information comes from the reproduced original specification card, which also contains test strengths, thread pitches for the staybolts and all the other information that validates the boiler as being properly constructed.

Steamtown's history notes that these engines were delivered with feedwater heaters (Elesco K-39), power reverse gear, and automatic or mechanical stokers. They were the first GTW locomotives to offer both the all-weather cab and the Vanderbilt tender. They were also Grand Trunk's only Baldwin-built Mountains; the railroad soon added a trailing axle to the design, creating some relatively light 4-8-4s.

Originally put in service on heavy passenger runs, the U-1c proved equally capable of hauling fast freights.

In the 30s, the friction bearings on all engine and tender axles were replaced by roller bearings. Later most were refitted with vanadium steel frames and Boxpok drivers.

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Class U-1d/e (Locobase 7332)

Data from CN to 1953 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange. (Thanks to Larry Bingham for his 7 July 2023 email correcting the railroad that owned these engines.)

These followed the U-1c (Locobase 5030) three years later and came from different builders. Canadian Locomotive Works delivered the first five (works numbers 1853-1857) in 1929; these had Walschaert valve gear. Montreal Locomotive Works followed in 1929-1930 with 12 more (works numbers 68343-68354) fitted with Baker gear.

Although the grate was essentially the same, tubes and flues were 7" (177 mm) shorter and the combustion chamber was a foot longer. The firebox also had thermic syphons. As with all the 4-8-2s in this series, piston valves measured 14" (356 mm) in diameter.

Some were oil-fired (4,000-gal tender capacity) and most had smoke deflectors (6047-6049, 6051-6056).