Canadian Pacific 4-6-4 "Hudson" Type Locomotives


The Canadian Pacific Railway ordered 20 of the 4-6-4 Hudsons from the Montreal Locomotive Works (which was part of the American Locomotive Company) in the late 1920s. The design goal for these new locomotives was to improve on the Class G3 4-6-2s that were the top motive power for the CPR. A 23% larger fire grate and a boiler with a large superheater and combustion chamber were made possible because of the 4-6-4 wheel arrangement. The CPR bought these locomotives in two orders. The first order for 10, Class H-1a, (road numbers 2800 through 2809), was delivered in 1929, and the second order for 10, Class H-1b (road numbers 2810 through 2819), was delivered in 1930. The introduction of the Hudsons improved running times and reduced the number of locomotive changes needed to cross Canada from fourteen to nine.

In the late 1930s the CPR, having concluded that streamlined shrouds were not cost effective, decided that there was value in an aestheticly pleasing locomotive and ordered more Hudsons designed to have softer lines and styled with an outstanding color livery. The first 30, Class H-1c (road numbers 2820 through 2849), arrived in 1937 and in 1938 another 10, Class H-1d (road numbers 2850 through 2859) were delivered.

The fifth and final order for five Class H-1e (road number 2860 through 2864), were similar in appearance but, because they were destined for operation in the far west, were built to burn oil and were delivered in 1940.

These Hudsons were highly successful and versatile on the CPR. There were 65 built in total, the vast majority for passenger service. These machines were very reliable and regularly ran an average of 180,000 kilometers a year, a very respectable figure for a steam locomotive. They could attain speeds up to 145 km/h while hauling 15 passenger cars. When they were replaced by diesel-electric ones in the mid 50's the 2858 survived hauling freight service for CPR.

In 1939, King George VI and Queen Elizabeth toured Canada by train from Quebec to Vancouver. They used a CPR train pulled by one the very new Hudsons, number 2850. This locomotive, as well as number 2851 which led a pilot train that proceeded the "Royal" train by one hour, were specifically painted for this assignment. The special livery included Royal blue and silver paint, stainless steel boiler cladding and the royal arms painted on the tender. Also a crown was painted on the skirt just ahead of the cylinders.

After the tour, both of the locomotives used were returned to the standard livery. Later the CPR was granted special permission to use the crown on the running boards of its newer Hudsons (road numbers 2820 through 2864) and to designate them as "Royal" Hudsons.

5 CPR Hudsons survive today.

Roster by Richard Duley

ClassQtyRoad NumbersYear BuiltBuilder

Class Details by Steve Llanso

Class H1a/H1b (Locobase 5874)

These locos -- designed by Chief of Motive Power & Rolling Stock Henry Blane Bowen -- were considered to be the cream of CPR passenger engines. The first set of 10 was delivered by MLW in 1929 with another 10 following in 1930.

This next set of 10 locomotives continued the Bowen Hudson design with slight differences. In one test reported by Railway Age in 1931, reported on a 130-mile run in which an H1 pulling a 19-car, 1,652-ton train. It's a summary of contemporary steam worked to its limit: Average steam pressure 274 psi, feedwater temperature 222 deg F, and average superheat temperatuture of 675 deg F.

One detail of the design were baffle walls under the grate and over the ashpan that diverted incoming air downward toward the center. Working in combination with 38.5 sq ft of arch tubes spaced to offer a wide brick span in the center and narrow ones at the side, the baffles kept cool air away from the sides, which reduced temperature differences and cracking. Much attention was paid during running to maintain an even temperature in the firebox.

Class H1c/H1d (Locobase 5875)

After a 7-year pause, Henry Bowen ordered another 30 Hudsons with the principal difference being the streamlining. Consisting mostly of rounded corners, the treatment was quite handsome when combined with the CP livery of black and red. Ten more came in 1938. As in the earlier engines, the firebox heating surface included 38.5 sq ft of arch tubes.

Runs of 811 miles (Toronto to Fort William) and 832 miles (Winnipeg-Calgary) made full use of the larger tenders.

The class earned British royal permission to call themselves the "Royal Hudsons" and to bear the Royal coat of arms after several of the class pulled the royal visitors around Canada in 1939.

Some of these engines ran into the mid-1960s.

Class H1e (Locobase 178)

These were the last five of Bowen's Hudsons. Like the others, the firebox heating surface included 38 sq ft of arch tubes. They were not very different from the 1937-1938 locomotives and were bought to flesh out express passenger rosters by taking on the British Columbian run between Revelstoke and Vancouver.

Class T-1 (Locobase 10798)

Data from American Engineering and Railroad Journal (November 1910), p. 435-439. See also Wright (Ed.), 1912 Locomotive Cyclopedia (3rd Edition) (New York Simmons-Boardman, 1912), pp. , 231.

The report explains that this pair was turned out to pull six coaches and a baggage car over the 47 miles between the Windsor Street Station and Point Fortune. In that distance, there were 7 regular stops and 13 flag stops westbound on a 120-minute schedule and 4 regular and 12 flag stops eastbound (105 minutes overall). Coal and water were taken on at Rigaud, which was 40 miles from Montreal.

Much attention was paid to both free steaming and weight control, the former being aided by 12" (305 mm) piston valves. The latter involved careful design of most of the structural members to maintain strength while minimizing materials use. One mark of its success was claimed to be coal consumption figures of 79 lb/train mile and 345 lb/thousand ton-miles. "

Specifications by Steve Llanso
Locobase ID5874 5875 178 10798
RailroadCanadian PacificCanadian PacificCanadian PacificCanadian Pacific
Road Numbers2800-28192820-28592860-28641992
BuilderMontreal LWMontreal LWMontreal LWAngus Works
Valve GearWalschaertWalschaertWalschaertWalschaert
Locomotive Length and Weight
Driver Wheelbase13.17'13.17'13.17'14.83'
Engine Wheelbase39.50'39.50'39.50'38.83'
Ratio of driving wheelbase to overall engine wheebase 0.33 0.33 0.33 0.38
Overall Wheelbase (engine & tender)80.52'80.52'80.88'38.83'
Axle Loading (Maximum Weight per Axle)
Weight on Drivers183800 lbs186800 lbs185800 lbs135000 lbs
Engine Weight351200 lbs354000 lbs365400 lbs236000 lbs
Tender Light Weight291900 lbs288650 lbs229600 lbs
Total Engine and Tender Weight643100 lbs642650 lbs595000 lbs236000 lbs
Tender Water Capacity14400 gals14400 gals14400 gals3000 gals
Tender Fuel Capacity (oil/coal)20 tons21 tons5400 gals4 tons
Minimum weight of rail (calculated) on which locomotive could run102 lb/yard104 lb/yard103 lb/yard75 lb/yard
Geometry Relating to Tractive Effort
Driver Diameter75"75"75"62"
Boiler Pressure275 psi275 psi275 psi200 psi
Cylinders (dia x stroke)22" x 30"22" x 30"22" x 30"20" x 26"
Tractive Effort45254 lbs45254 lbs45254 lbs28516 lbs
Factor of Adhesion (Weight on Drivers/Tractive Effort) 4.06 4.13 4.11 4.73
Heating Ability
Firebox Area326 sq. ft326 sq. ft326 sq. ft156 sq. ft
Grate Area80.80 sq. ft80.80 sq. ft80.80 sq. ft33.10 sq. ft
Evaporative Heating Surface3834 sq. ft3791 sq. ft3791 sq. ft1801 sq. ft
Superheating Surface1640 sq. ft1640 sq. ft1542 sq. ft266 sq. ft
Combined Heating Surface5474 sq. ft5431 sq. ft5333 sq. ft2067 sq. ft
Evaporative Heating Surface/Cylinder Volume290.48287.22287.22190.50
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation2222022220222206620
Same as above plus superheater percentage2888628886286647481
Same as above but substitute firebox area for grate area11654511654511564935256
Power L152670525585026110876
Power MT1895.281860.871789.12532.83




Introduction and roster provided by Richard Duley. Class details and specifications provided by Steve Llanso of Sweat House Media.