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

Canadian National

The Canadian National Railways was formed in 1923 to rescue several financially troubled rail lines. At the time of the merger new motive power was badly needed and the CNR's first order for new locomotives was given to the Canadian Locomotive Company to build sixteen "Mountain" type locomotives.

This batch of sixteen 4-8-2s were delivered in 1923 and was designated as Class U-1-a and assigned road numbers 6000 through 6015. These locomotives had 26 x 30 cylinders, 73" drivers, a 210 psi boiler pressure and exerted 49,588 lbs of tractive effort. They weighed 354,110 lbs and were used on express passenger trains between Montreal and Toronto.

Twenty-one more "Mountains" were delivered from the Canadian Locomotive Company during 1924 and 1925. These locomotives were designated as Class U-1-b and given road numbers 6016 through 6036. They were similar to the Class U-1-a "Mountains" and were added to the passenger motive power roster.

Five more 4-8-2s (Class U-1-d, road numbers 6042 through 6046) from the Canadian Locomotive Company and twelve more 4-8-2s (Class U-1-e, road numbers 6047 through 6058) from the Montreal Locomotive Works were delivered in 1929 and 1930. These last two groups had minor improvements but were essentially the same as the sixteen delivered in 1923.

A final batch of twenty "Mountains" were delivered by the Montreal Locomotive Works in 1944. This group was designated as Class U-1-f and assigned road numbers 6060 through 6079. These very heavy (416,500 lbs) locomotives were semi-streamlined and intended to be used primarily for fast passenger service. Some were also used in a dual freight and passenger capacity. They were capable of reaching speeds up to 100 miles per hour.

The U-1-f class locomotives had a distinguishing conical nose which housed the headlight and the number lamps. The stack was flaired after the British style. They were normally painted in CNR's passenger colors of black with green board skirts, cab and tender. Some of them were eventually converted to burn oil.

There are five surviving CNR "Mountains".

Central Vermont

The Central Vermont Railroad purchased four Class U-1-a "Mountains" from the American Locomotive Company in 1927. These locomotives were assigned road numbers 600 through 603 and had 26 x 28 cylinders, 73" drivers, a boiler pressure of 200 psi, a total weight of 325,000 lbs and a tractive effort of 44,000 pounds. Later,the boiler pressure was raised to 200 psi and the tractive effort increased to 46,300 pounds.

On the Central Vermont, the "Mountains" were used on through trains and regularly led the "The Ambassador", "The Montrealer", "The New Englander" and "The Washingtonian". Occasionally, they were used in freight service. Number 602 was the last steam locomotive to pull a freight train on the Central Vermont Railroad.

Numbers 600, 601 and 603 were retired on 7/31/56 and number 602 on 6/1/57. There are no surviving Central Vermont "Mountains".

Grand Trunk Western

The Grand Trunk Western Railway's passenger traffic had increased on its Chicago Division to the point that it had to double-head its "Pacifics" to keep to its scheduled running times. Taking the lead from its parent, the Canadian National Railway, the GTW ordered five "Mountains" from the Baldwin Locomotive Works and took delivery of them in 1925. These locomotives were designated as Class U-1-c and assigned road numbers 6037 through 6041.

By 1929, the Grand Trunk Western Railroad (as it was known by then) was using these five 4-8-2s for fast freight as well as for the passenger trains that they originally bought them to lead.

There is one surviving GTW "Mountain", number 6039, at Steamtown National Historic Site in Scranton, PA.


ClassQuantityRoad NumbersYear BuiltBuilder
U-1-a166000 - 60151923CLC
U-1-b216016 - 60361924-1925CLC
U-1-d56042 - 60461929-1930CLC
U-1-e126047 - 60581929-1930MLW
U-1-f206060 - 60791944MLW

Class Details by Steve Llanso of Sweat House Media

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.

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.

The CLC supplied 37 Mountains to the CN in two years. A majority was fitted with the Robinson superheater while the others, shown in Locobase 7334, had Schmidt Type A superheaters. The Robinson engines showed in this entry had works #1696-1711 (1923) and 1764-1769 (1924).

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 says that the Robinson superheaters were replaced by the Schmidt design - the diagram's superheater surface area difference was not changed, however.

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.

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.

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.

These followed the U-1c (Locobase 5030) by 3 years and came from different builder. Canadian Locomotive Works delivered the first five (works #1853-1857) in 1929; these had Walschaert valve gear. Montreal Locomotive Works followed in 1929-1930 with 12 more (works #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).

Principal Dimensions by Steve Llanso of Sweat House Media
ClassU-1-fU-1a/U-1b - RobinsonU-1b - SchmidtU-1cU-1d/e
Locobase ID197 7333 7334 5303 7332
RailroadCanadian National (CNR)Canadian National (CNR)Canadian National (CNR)Grand Trunk Western (CNR)Grand Trunk Western (CNR)
Number in Class202115517
Road Numbers6060-60796000-6015, 6031-60366016-60306037-60416042-6058
Number Built202115517
BuilderMontreal LWCanadian Locomotive CoCanadian Locomotive CoBaldwinseveral
Valve GearWalschaertWalschaertWalschaertWalschaertBaker or Walschaert
Locomotive Length and Weight
Driver Wheelbase (ft / m)19 / 5.7919.50 / 5.9419.50 / 5.9419.50 / 5.9419.50 / 5.94
Engine Wheelbase (ft / m)41.75 / 12.7341.75 / 12.7341.75 / 12.7341.82 / 12.75
Ratio of driving wheelbase to overall engine wheebase 0.47 0.47 0.47 0.47
Overall Wheelbase (engine & tender) (ft / m)80.90 / 24.6679.15 / 24.1279.15 / 24.1280.31 / 24.4874.58 / 22.73
Axle Loading (Maximum Weight per Axle) (lbs / kg)
Weight on Drivers (lbs / kg)236,950 / 107,479235,390 / 106,771233,790 / 106,045231,370 / 104,948232,800 / 105,596
Engine Weight (lbs / kg)365,700 / 165,879354,300 / 160,708355,570 / 161,284354,110 / 160,622352,720 / 159,991
Tender Loaded Weight (lbs / kg)281,840 / 127,841240,750 / 109,202248,300 / 112,627250,000 / 113,398221,300 / 100,380
Total Engine and Tender Weight (lbs / kg)647,540 / 293,720595,050 / 269,910603,870 / 273,911604,110 / 274,020574,020 / 260,371
Tender Water Capacity (gals / ML)11,000 / 41.6710,000 / 37.8810,000 / 37.8813,575 / 51.429500 / 35.98
Tender Fuel Capacity (oil/coal) (gals/tons / ML/MT)5000 / 18.9017 / 15.5017 / 15.5018 / 16.4015 / 13.60
Minimum weight of rail (calculated) (lb/yd / kg/m)99 / 49.5098 / 4997 / 48.5096 / 4897 / 48.50
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)73 / 185473 / 185473 / 185473 / 185473 / 1854
Boiler Pressure (psi / kPa)260 / 17.90210 / 14.50210 / 14.50210 / 14.50250 / 17.20
High Pressure Cylinders (dia x stroke) (in / mm)24" x 30" / 610x76226" x 30" / 660x76226" x 30" / 660x76226" x 30" / 660x76224" x 30" / 610x762
Tractive Effort (lbs / kg)52,313 / 23728.8149,589 / 22493.2249,589 / 22493.2249,589 / 22493.2250,301 / 22816.18
Factor of Adhesion (Weight on Drivers/Tractive Effort) 4.53 4.75 4.71 4.67 4.63
Heating Ability
Firebox Area (sq ft / m2)386 / 35.86319 / 29.65319 / 29.65307 / 28.52319 / 29.65
Grate Area (sq ft / m2)70.20 / 6.5266.77 / 6.2166.77 / 6.2166.70 / 6.2066.70 / 6.20
Evaporative Heating Surface (sq ft / m2)3584 / 332.964049 / 376.304049 / 376.304038 / 375.143900 / 362.45
Superheating Surface (sq ft / m2)1570 / 145.86810 / 75.281057 / 98.231048 / 97.361040 / 96.65
Combined Heating Surface (sq ft / m2)5154 / 478.824859 / 451.585106 / 474.535086 / 472.504940 / 459.10
Evaporative Heating Surface/Cylinder Volume228.16219.64219.64219.04248.28
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation18,25214,02214,02214,00716,675
Same as above plus superheater percentage23,72816,40516,96616,94820,177
Same as above but substitute firebox area for grate area130,46878,37881,05878,00996,498
Power L139,56017,92621,00720,79628,765
Power MT1472.29671.57792.38792.621089.62

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Wes Barris