Great Northern 2-8-8-2 "Chesapeake" Type Locomotives

Class Details by Steve Llanso

Class R-1 - Baldwin (Locobase 14966)

Data from DeGolyer, Vol 76, pp. 316+, and from GN 1 - 1929 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive collection. Works numbers were 58480-58481 in June 1925 and 58528, 58542 in July.

As designed by Baldwin, the Belpaire firebox on these oil-burning behemoths had no arch tubes and a combustion chamber that contributed 160 sq ft (14.85 sq m) to direct heating surface. However, the specs note that the firebox was to make provisions for a brick arch and tubes and that the engine and tender "be arranged for future application of Duplex or Standard Stokers. Indeed, the railway soon installed arch tubes that added another 64 sq ft (5.95 sq m).

The boiler had exhaust steam injectors, and steam was distributed through 14" (356 mm) diameter piston valves. Baldwin calculated the tractive effort using the GN's preferred coefficient of .765 instead of the standard 0.85 and came up with 127,500 lb (57,833 kg)..

The driving wheelbase of all sixteen drivers measured 43 feet 7 inches (13.28 metres).

The cylindrical Vanderbilt tender had a flat top and two 6-wheel Commonwealth trucks equalized to give "equal distribution of weight on each axle."

For the last ten R-1s built by Great Northern to modified specs at the Hillyard Shops, see Locobase 14966.

By 1952, the first three Baldwins had been retired to serve as stationary boilers in ore steaming service.

Class R-1s (Locobase 320)

Data from tables in 1930 Locomotive Cyclopedia and from GN 1 - 1929 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive collection. Produced at the Great Northern's Hillyard Shops in 1927 (2) and 1928 (8).

Baldwin's 2030 may have seemed big enough to most railways, but the Great Northern wanted more power without a drop in the engine's factor of adhesion. So two years later, it rolled out very similar locomotives with more direct heating surface area, more weight on the drivers, and a boiler set 15 psi (1.03 bar) higher. Calculating the tractive effort using a coefficient of 0.765 instead of the standard 0.85 yielded 136,600 lb (61,961 kg).

At first, the Belpaire firebox had only the combustion chamber that contributed 155 sq ft (14.4 sq m). Soon, however, the railway had installed arch tubes that added another 64 sq ft (5.95 sq m) to direct heating surface, the boiler had exhaust steam injectors, and steam was distributed through 14" (356 mm) diameter piston valves.

Tube count later reduced on 2039 and 2042 to 294.

By 1952, the first three Baldwins had been retired to serve as stationary boilers in ore steaming service.

Class R-2 (Locobase 321)

Data from tables from 1930 Locomotive Cyclopedia and GN 4 - 1946 Locomotive Diagram supplied in May 2005 by Allen Stanley from his extensive collection. See also Charles R. Wood, Lines West (New York: Bonanza Books, 1967), p. 88. Produced in 1929-1930.

The Great Northern's essay in simple articulateds produced this immense specimen that reflected the influence of the superpower revolution of the late 1920s. Note the size of the boiler and the Type E superheater surface area. Compared to the R-1s by Baldwin, these engines had 10% more EHS, 85.4% more SHS, and a 8.8% lower BDF. The GN calculated tractive effort after applying a coefficient of .765 instead of the .85 usually used. The result was a still impressive 146,000 lb (66,225 kg).

The boiler was fitted with exhaust steam injector. The Belpaire firebox's heating surface included 178 sq ft (16.5 sq m) from the combustion chamber and a surprisingly high 78 sq ft (7.25 sq m) in arch tubes.

Notice too that these engines grossed out at just over 501 tons(455 metric tons) with loaded tender. They were the biggest locomotives built west of the Mississippi.

"As prime movers of tonnage on the GN," wrote Charles Wood,"they were unexcelled and reflected the continual search for bigger and better motive power that dated back to the days of James J Hill."

The class operated from Minot, ND through all of Montana to Spokane, WA, reaching Great Falls, Mont from Shelby. Late in their careers, all were converted to a mixed cylinder diameter of 26" in front, 28" in the rear. See Locobase 14965 for the result.

Class R-2 - 1946 (Locobase 14965)

Data from GN 3 - 1952 Locomotive Diagram supplied in May 2005 by Allen Stanley from his extensive collection.

Locobase 320 describes the original configuration of these immense articulateds as they were delivered by the GN's own shops in 1930. Within 16 years, the GN had substantially modified the design. It appears the railway thought the design was either over-cylindered for its boiler or under-weight for the power they wanted to develop. So the shops took the very unusual step of reducing the cylinder diameter in the front engine set while retaining the original dimension in the rear. All four piston valves measured 14" (356 mm) in diameter.

Boiler was fitted with exhaust steam injector. The Belpaire firebox's heating surface included 178 sq ft (16.5 sq m) from the combustion chamber and a surprisingly high 142 sq ft (13.2 sq m) in circulators. Heating surface area as a percentage of total EHS increased, but still was smaller than a large number of American articulateds. The boiler's 2 1/4" tube count dropped by 15.

Weight on the drivers jumped by a telling 24 short tons (21.8 metric tons) and overall weight grew by almost 28 short tons (25.5 metric tons). Tractive effort as calculated by the GN (which used a coefficient of 76.5% rather than the more usual .85) dropped slightly to 142,055 lb (64,435 kg). Dividing that value into the higher adhesive weight yielded a healthy 4.14 factor of adhesion.

By 1946, only the 2047 and the 2054 retained the original cylinder volume.


Specifications by Steve Llanso
ClassR-1 - BaldwinR-1sR-2R-2 - 1946
Locobase ID14966 320 321 14965
RailroadGreat Northern (GN)Great Northern (GN)Great Northern (GN)Great Northern (GN)
CountryUSAUSAUSAUSA
Whyte2-8-8-22-8-8-22-8-8-22-8-8-2
Road Numbers2030-20332034-20432044-20592044-2059
GaugeStdStdStdStd
BuilderBaldwinGNRGNRGNR
Year1925192719291929
Valve GearWalschaertWalschaertWalschaertWalschaert
Locomotive Length and Weight
Driver Wheelbase16.50'16.50'16.50'16.50'
Engine Wheelbase58.17'58.17'70.60'70.60'
Ratio of driving wheelbase to overall engine wheebase 0.28 0.28 0.23 0.23
Overall Wheelbase (engine & tender)96.29'96.29'106.02'107.03'
Axle Loading (Maximum Weight per Axle)67500 lbs68000 lbs74000 lbs
Weight on Drivers510000 lbs532800 lbs544000 lbs592000 lbs
Engine Weight578000 lbs594940 lbs630750 lbs686440 lbs
Tender Light Weight321560 lbs321560 lbs372780 lbs372780 lbs
Total Engine and Tender Weight899560 lbs916500 lbs1003530 lbs1059220 lbs
Tender Water Capacity16800 gals16000 gals22000 gals22000 gals
Tender Fuel Capacity (oil/coal)5800 gals5800 gals5800 gals5800 gals
Minimum weight of rail (calculated) on which locomotive could run106 lb/yard111 lb/yard113 lb/yard123 lb/yard
Geometry Relating to Tractive Effort
Driver Diameter63"63"63"63"
Boiler Pressure210 psi225 psi240 psi240 psi
High Pressure Cylinders (dia x stroke)28" x 32" (4)28" x 32" (4)28" x 32" (4)26" x 32" (2)
Low Pressure Cylinders (dia x stroke)28" x 32" (2)
Tractive Effort142165 lbs152320 lbs162475 lbs151283 lbs
Factor of Adhesion (Weight on Drivers/Tractive Effort) 3.59 3.50 3.35 3.91
Heating Ability
Firebox Area432 sq. ft485 sq. ft559 sq. ft623 sq. ft
Grate Area108 sq. ft108 sq. ft126 sq. ft126 sq. ft
Evaporative Heating Surface7142 sq. ft7161 sq. ft7947 sq. ft7834 sq. ft
Superheating Surface1896 sq. ft1920 sq. ft3515 sq. ft3515 sq. ft
Combined Heating Surface9038 sq. ft9081 sq. ft11462 sq. ft11349 sq. ft
Evaporative Heating Surface/Cylinder Volume156.58157.00174.23398.39
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation22680243003024030240
Same as above plus superheater percentage27443294033961439614
Same as above but substitute firebox area for grate area109771132041175750195871
Power L112746139162341325268
Power MT440.79460.65759.07752.79

Photos

Reference

Credits

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