Chicago, Rock Island & Pacific 2-10-2 "Santa Fe" Locomotives in the USA

The Chicago, Rock Island & Pacific Railroad took delivery of ten "Santa Fe" type locomotives in 1918. These locomotives were built by the American Locomotive Company and were designated as Class N-78 and assigned road numbers 3001 through 3010. Fifteen more ALCO-built 2-10-2s were added to the roster in 1920. This group was also designate as Class N-78 and carried road numbers 3011 through 3025.

All twenty-five of these Class N-78s were coal fired and had 63" diameter drivers, 30" x 32" cylinders, a 200 psi boiler pressure, they exerted 77,715 pounds of tractive effort and each weighed 385,400 pounds. Their firebox had 116.7 square feet of thermic syphons.

In 1925, another group of ALCO-built "Santa Fes" was added to the roster. These locomotives were oil-fired and were also classified as Class N-78. They had 63" diameter drivers, 30" x 32" cylinders, a 200 psi boiler pressure, they exerted 77,715 pounds of tractive effort and each weighed 405,000 pounds. The firebox had 121 sq ft of thermic syphons and some of the boilers had feedwater heater,

All thirty-five of the CRIP's "Santa Fes" as delivered had counterbalancing problems and were limited to 30 mph. Refitting them with disk drivers reduced the problem and reducing the pounding.

There are no surviving CRIP 2-10-2 "Santa Fe" type locomotives.


Roster

ClassQty.Road NumbersYear BuiltBuilderNotes
N-78103001-30101918ALCONumbers 3001-3010 scrapped between 1939 and 1952.
N-78153011-30251920ALCONumbers 3011-3025 scrapped between 1939 and 1952.
N-78103026-30351925ALCONumbers 3026-3035 scrapped between 1939 and 1952.

Class Details by Steve Llanso of Sweat House Media

Class MP-90 class (N-83 road class) (Locobase 77)

Data from 1930 Locomotive Cyclopedia, supplemented by RI to 1951 Combined Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange; and "Class 2-10-2 S-405"representing Order No. S-1505 (July 1925), American Locomotrve Company builder's card.. (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; Chris's 7 May 2023 email supplied the builder's card and comments on the boiler pressure and superheater area as delivered..) Works numbers were 6633066339 in July 1925.

These were the last ten of the 35 Santa Fes delivered to the Rock Island, which were delivered as coal burners trailing tenders carrying 18 tons 16.4 metric tons) fed to the grate by Elvin stokers. Installing trailing-truck booster engines added 3,300 lb (1,497 kg) to adhesive weight; an additional 1,700 lb (771 kg) came from the trailing truck. After deducting 200 lb (90.7 kg) from the front truck, engine weight increased by 4,800 lb (2,177 kg) .

The class offered an increase in superheater area; and tubes and flues were 1 ft 10" (559 mm) longer than those of the first group described in Locobases 16315 and 7234. Chris Hohl noted that the boiler pressure was set to 200 psi (12.90 bar); by 1930, the setting had been adjusted to the 215 psi shown in the specs. A similar change applied to the superheater area, which Alco calculated as 1,424 sq ft (132.29 sq m). Later Rock Island diagrams show the 1,375 sq ft given in Locobase's specs.

The firebox had 121 sq ft (11.24 sq m) of thermic syphons and some of the boilers had feedwater heaters (3026-3029 used Worthington BLs and 3030-3032 had Elescos). Elesco exhaust steam injectors served the 3033-3035. Fourteen-inch (381 mm) piston valves supplied steam to the cylinders.

By 1937, the Rock Island had converted the entire class to oil burning. The Rock could choose from several different tenders. In addition to the heaviest and most capacious tenders shown in the specs, any given N-83 might trail:

Weight Water capacity Oil capacity

217,600 lb ( 98,702 kg) 12,000 US gallons (45,420 litres) 3,400 (12,870 litres)

224,600 (101,877) 12,000 (45,420) 4,100 (15,519)

241,450 (109,520) 15,000 (56,775) 3,400 (12,870)

3029 later reverted to coal burning, feeding its fuel with a Standard BK stoker.

Later refitting with disk drivers ameliorated the pounding endemic to all North American 2-10-2s and allowed a speed rating increase from 30 mph (48 kph) to 50 mph (80.5 kph)

3028 was sold for scrap in March 1949. Seven of the class followed in 1950, 3032 went in November 1951, and 3031 closed out the class in January 1951.


Class N-72 (Locobase 16315)

Data from "Rock Island 2-10-2 Locomotive", Railway Mechanical Engineer, Volume 93, No 1 (January 1919), pp. 41-43; and "Mikado, Santa Fe, and Mountain Type Locomotives for the Chicago, Rock Island and Pacific Railway", Railway and Locomotive Engineering, Volume 34, No 2 (February 1921), pp. 33-35. (Thanks to Chris Hohl for his 6 October 2017 email noting the original specifications and pointing Locobase to the 1919 journal report that supllied the correct data.) Brooks produced the locomotives in two batches -- 3001-3010 (works numbers were 58305-58314 in May 1918

1918 locomotives were delivered with combustion chambers and arch tubes, the latter contributed 36 sq ft (3.35 sq m) to the direct heating surface area. The 1920 locomotives incorporated 141 sq ft () of Nicholson thermic syphons; see Locobase 7234. Fourteen-inch (381 mm) piston valves actuated by outside radial valve gear admitted steam to the cylinders.

Drury's (1993) assessment: "Even with 63" drivers, [they] had counterbalancing problems and were limited to 30 mph." Not long after they entered service, the class's boiler pressure was increased to 200 psi (13.8 bar). Later refitting with disk drivers ameliorated the pounding and more direct heating surface and a stil higher boiler pressure increased power even more.


Class N-83 (Locobase 7234)

Data from RI1 -1942 and RI to 1951 Combined Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange. See also "Mikado, Santa Fe, and Mountain Type Locomotives for the Chicago, Rock Island and Pacific Railway", Railway and Locomotive Engineering, Volume 34, No 2 (February 1921), pp. 33-35. (Thanks to Chris Hohl for his 28 October 2019 email noting the original boiler pressure, as well as tender weight and capacity.) Works numbers were 62162-62176 in October 1920.

Locobase 16315 shows the original set of ten Santa Fes as they arrived on the Rock Island in 1918. That batch's supplemental firebox heating surface amounted to the combustion chamber and arch tubes. The 1920 locomotives arrived fitted with 141 sq ft (10.85 sq m) of thermic syphons in place of the original arch tubes. One of the syphons was later removed, reducing syphon area to 116.7 sq ft (10.84 sq m) and firebox heating surface area to 458.2 sq ft (42.57 sq m). This batch retained the 14" (356 mm) piston valves and 185 psi operating pressure.

Drury's (1993) assessment that "Even with 63" drivers, [they] had counterbalancing problems and were limited to 30 mph." led to refitting with disk drivers that ameliorated the pounding and allowed a permissible speed of 50 mph (81 kph). By 1942, the Rock Island had raised boiler pressure to 215 psi (14.8 bar), increasing tractive effort to 83,453 lb (37,895 kg or 371.6 kN) while reducing minimum factor of adhesion to 3.69.

Chris Hohl pointed out that when these were delivered as coal burners, their loaded tenders weighted 192,500 lb and carried 16 tons of coal (14.55 metric tons). When converted to oil burning, tender water capacity remained the same; the largest-capacity oil tender used by the Rock Island's 2-10-2s is shown in the Locobase specs. Those retained as coal burners eventually trailed the heaviest tenders, which weighed 241,000 lb (109,316 kg) when carrying 14,000 US gallons (52,990 litres) of water and 18 tons (16.4 metric tons) of coal and brought the full power system weight of engine and tender to 632,000 lb (286,670 kg).

Principal Dimensions by Steve Llanso of Sweat House Media

ClassMP-90 class (N-83 road class)N-72N-83
Locobase ID77 16315 7234
RailroadChicago, Rock Island & Pacific (CRI&P)Chicago, Rock Island & Pacific (CRI&P)Chicago, Rock Island & Pacific (CRI&P)
CountryUSAUSAUSA
Whyte2-10-22-10-22-10-2
Number in Class101015
Road Numbers3026-30353001-30103011-3025
GaugeStdStdStd
Number Built101015
BuilderAlco-SchenectadyAlco-BrooksAlco-Brooks
Year192519181920
Valve GearBakerBakerBaker
Locomotive Length and Weight
Driver Wheelbase (ft / m)22.50 / 6.8622.50 / 6.8622.50 / 6.86
Engine Wheelbase (ft / m)42.58 / 12.9841.25 / 12.5741.25 / 12.57
Ratio of driving wheelbase to overall engine wheelbase 0.53 0.55 0.55
Overall Wheelbase (engine & tender) (ft / m)82.67 / 25.2080.23 / 24.4580.23 / 24.45
Axle Loading (Maximum Weight per Axle) (lbs / kg)
Weight on Drivers (lbs / kg)317,500 / 144,016302,500 / 137,212308,500 / 139,933
Engine Weight (lbs / kg)405,000 / 183,705383,000 / 173,726391,000 / 177,355
Tender Loaded Weight (lbs / kg)249,150 / 113,013189,900 / 86,137207,100 / 93,939
Total Engine and Tender Weight (lbs / kg)654,150 / 296,718572,900 / 259,863598,100 / 271,294
Tender Water Capacity (gals / ML)15,000 / 56.8210,000 / 37.8810,000 / 37.88
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT)4100 / 372716 / 154550 / 17,222
Minimum weight of rail (calculated) (lb/yd / kg/m)106 / 53101 / 50.50103 / 51.50
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)63 / 160063 / 160063 / 1600
Boiler Pressure (psi / kPa)215 / 14.80185 / 12.80215 / 14.80
High Pressure Cylinders (dia x stroke) (in / mm)30" x 32" / 762x81330" x 32" / 762x81330" x 32" / 762x813
Tractive Effort (lbs / kg)83,543 / 37894.5171,886 / 32606.9883,543 / 37894.51
Booster (lbs)13,075
Factor of Adhesion (Weight on Drivers/Tractive Effort) 3.80 4.21 3.69
Heating Ability
Tubes (number - dia) (in / mm)210 - 2.25" / 57226 - 2.25" / 57226 - 2.25" / 57
Flues (number - dia) (in / mm)50 - 5.5" / 14046 - 5.5" / 14046 - 5.5" / 140
Flue/Tube length (ft / m)23.08 / 7.0321.25 / 6.4821.25 / 6.48
Firebox Area (sq ft / m2)445 / 41.34391 / 36.32532 / 49.42
Grate Area (sq ft / m2)80.30 / 7.4680.20 / 7.4580.20 / 7.45
Evaporative Heating Surface (sq ft / m2)4940 / 458.944608 / 428.094692 / 436.06
Superheating Surface (sq ft / m2)1375 / 127.741180 / 109.621197 / 111.25
Combined Heating Surface (sq ft / m2)6315 / 586.685788 / 537.715889 / 547.31
Evaporative Heating Surface/Cylinder Volume188.69176.01179.22
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation17,26514,83717,243
Same as above plus superheater percentage21,06317,80420,692
Same as above but substitute firebox area for grate area116,72486,802137,256
Power L116,84912,74915,629
Power MT584.97464.57558.44

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