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.
|Class||Qty.||Road Numbers||Year Built||Builder||Notes|
|N-78||10||3001-3010||1918||ALCO||Numbers 3001-3010 scrapped between 1939 and 1952.|
|N-78||15||3011-3025||1920||ALCO||Numbers 3011-3025 scrapped between 1939 and 1952.|
|N-78||10||3026-3035||1925||ALCO||Numbers 3026-3035 scrapped between 1939 and 1952.|
As delivered, firebox heating surface area included 36 sq ft (3.35 sq m) of arch tubes. 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; See Locobase 7234.
These were the last ten of the 35 Santa Fes delivered to the Rock Island and manifested an increase in superheater area; the first 25 are described in Locobase 20278. The firebox had 121 sq ft of thermic syphons and some of the boilers had feedwater heater (Four had Worthington BLs and three had Elescos). Three more had exhaust steam injectors. The diagrams show a superheater area of 1,350 sq ft vs the number from the Locomotive Cyclopedia. In any case, the tubes and flues were 1 ft 10" (559 mm) longer than those of the first group.
Drury's (1993) assessment: "Even with 63" drivers, [they] had counterbalancing problems and were limited to 30 mph." Later refitting with disk drivers ameliorated the pounding.
Locobase 16315shows the original set of 25 Santa Fes as they arrived on the Rock Island in 1918. The later addition of 116.7 sq ft (10.85 sq m) of thermic syphons in place of the original 36 sq ft (3.35 sq m) of arch tubes in these Santa Fes brought the firebox heating surface up to 448.2 sq ft (41.65 sq m). 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.
The largest-capacity oil tender 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|
|Railroad||Rock Island (CRI & P)||Rock Island (CRI & P)||Rock Island (CRI & P)|
|Number in Class||25||10||25|
|Locomotive Length and Weight|
|Driver Wheelbase (ft / m)||22.50 / 6.86||22.50 / 6.86||22.50 / 6.86|
|Engine Wheelbase (ft / m)||41.25 / 12.57||42.60 / 12.98||41.25 / 12.57|
|Ratio of driving wheelbase to overall engine wheebase||0.55||0.53||0.55|
|Overall Wheelbase (engine & tender) (ft / m)||80.23 / 24.45||82.67 / 25.20||80.23 / 24.45|
|Axle Loading (Maximum Weight per Axle) (lbs / kg)|
|Weight on Drivers (lbs / kg)||302,500 / 137,212||317,500 / 144,016||304,300 / 138,028|
|Engine Weight (lbs / kg)||383,000 / 173,726||405,000 / 183,705||385,400 / 174,815|
|Tender Loaded Weight (lbs / kg)||189,900 / 86,137||223,600 / 101,423||207,100 / 93,939|
|Total Engine and Tender Weight (lbs / kg)||572,900 / 259,863||628,600 / 285,128||592,500 / 268,754|
|Tender Water Capacity (gals / ML)||10,000 / 37.88||12,000 / 45.45||10,000 / 37.88|
|Tender Fuel Capacity (oil/coal) (gals/tons / ML/MT)||16 / 14.50||18 / 16.40||4550 / 17.20|
|Minimum weight of rail (calculated) (lb/yd / kg/m)||101 / 50.50||106 / 53||101 / 50.50|
|Geometry Relating to Tractive Effort|
|Driver Diameter (in / mm)||63 / 1600||63 / 1600||63 / 1600|
|Boiler Pressure (psi / kPa)||185 / 12.80||215 / 14.80||215 / 14.80|
|High Pressure Cylinders (dia x stroke) (in / mm)||30" x 32" / 762x813||30" x 32" / 762x813||30" x 32" / 762x813|
|Tractive Effort (lbs / kg)||71,886 / 32606.98||83,543 / 37894.51||83,543 / 37894.51|
|Factor of Adhesion (Weight on Drivers/Tractive Effort)||4.21||3.80||3.64|
|Firebox Area (sq ft / m2)||391 / 36.32||445 / 41.34||458.20 / 41.66|
|Grate Area (sq ft / m2)||80.20 / 7.45||80.30 / 7.46||80.30 / 7.46|
|Evaporative Heating Surface (sq ft / m2)||4608 / 428.09||4940 / 459.11||4741 / 440.45|
|Superheating Surface (sq ft / m2)||1180 / 109.62||1424 / 132.34||1150 / 106.84|
|Combined Heating Surface (sq ft / m2)||5788 / 537.71||6364 / 591.45||5891 / 547.29|
|Evaporative Heating Surface/Cylinder Volume||176.01||188.69||181.09|
|Computations Relating to Power Output (More Information)|
|Robert LeMassena's Power Computation||14,837||17,265||17,265|
|Same as above plus superheater percentage||17,804||21,063||20,717|
|Same as above but substitute firebox area for grate area||86,802||116,724||118,216|