Atchison, Topeka & Santa Fe 2-8-8-2 "Chesapeake" Locomotives in the USA

Class Details by Steve Llanso of Sweat House Media

Class 1700 (Locobase 3559)

Data from Record of Recent Construction #68 (Baldwin Locomotive Works, 1910), p.34-35. See also complete specs at Baldwin Locomotive Works Specification for Engines as digitized by the DeGolyer Library of Southern Methodist University, Volume 33, pp.190-197; and "Record Breaking Freight and Passenger Locomotives for the Santa Fe", American Engineer and Railroad Journal, Volume 83, No 12 (December 1909), pp. 476-482. (Thanks to Chris Hohl for his 20 January 2018 email giving the correct LP cylinder and pointing the absence of any information on the reheater.) diameter. Works numbers were 33868-33869 in October 1909.

These were, says Drury (1993), the best "(or least unsuccessful)" of the small roster of articulateds on the Santa Fe. Although they had the "preheater" that was in brief vogue among US articulated builders, they avoided the jointed boilers of the later 2-6-6-2s. Still, deploying a boiler, 10 ft 9 in (3.28 m) long "intermediate combustion chamber" containing both a Jacobs superheater and Santa Fe reheater, and a front boiler housing the big bundle of feedwater heater tubes made for a long locomotive.

Baldwin and the Santa Fe calculated evaporative heating surface area using the firebox, tube heating surface area, and the feed water heater's 417 tubes of 2 1/4" diameter and 6 ft 8 (2.03 m) in length, which contributed 1,617 sq ft (150.22 sq m). The 1,201 sq ft (111.58 sq m) of the reheater, which added heat to the exhaust coming from the HP cylinders before it entered the LP cylinders, didn't figure in the overall calculation.

HP piston valves measured 13" (330 mm) in diameter and were set up for inside . LP valves were 2" (50.8 mm) bigger and were set up for outside admission.

The pair also deployed the stayless Jacobs-Shupert firebox; see Locobase 463 for a description of this unusual firebox design. A Booth oil burner was mounted in the front of the firebox.

In 1924, the engine units were removed and placed under separate boilers, creating two Mikados each.

Principal Dimensions by Steve Llanso of Sweat House Media

Locobase ID3559
RailroadAtchison, Topeka & Santa Fe (ATSF)
Number in Class2
Road Numbers1700-1701
Number Built2
Valve GearWalschaert
Locomotive Length and Weight
Driver Wheelbase (ft / m)33 / 10.06
Engine Wheelbase (ft / m)59.83 / 18.24
Ratio of driving wheelbase to overall engine wheelbase 0.55
Overall Wheelbase (engine & tender) (ft / m)98.44 / 30
Axle Loading (Maximum Weight per Axle) (lbs / kg)54,900 / 24,902
Weight on Drivers (lbs / kg)412,384 / 187,054
Engine Weight (lbs / kg)462,448 / 209,763
Tender Loaded Weight (lbs / kg)233,520 / 105,923
Total Engine and Tender Weight (lbs / kg)695,968 / 315,686
Tender Water Capacity (gals / ML)12,000 / 45.45
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT)4000 / 15,140
Minimum weight of rail (calculated) (lb/yd / kg/m)86 / 43
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)63 / 1600
Boiler Pressure (psi / kPa)220 / 15.20
High Pressure Cylinders (dia x stroke) (in / mm)26" x 34" / 660x864
Low Pressure Cylinders (dia x stroke) (in / mm)38" x 34" / 965x864
Tractive Effort (lbs / kg)92,937 / 42155.56
Factor of Adhesion (Weight on Drivers/Tractive Effort) 4.44
Heating Ability
Tubes (number - dia) (in / mm)387 - 2.25" / 57
Flues (number - dia) (in / mm) - 2.25" / 57
Flue/Tube length (ft / m)21.52 / 6.56
Firebox Area (sq ft / m2)236 / 21.93
Grate Area (sq ft / m2)68.50 / 6.37
Evaporative Heating Surface (sq ft / m2)6621 / 615.33
Superheating Surface (sq ft / m2)544 / 50.56
Combined Heating Surface (sq ft / m2)7165 / 665.89
Evaporative Heating Surface/Cylinder Volume316.94
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation15,070
Same as above plus superheater percentage16,276
Same as above but substitute firebox area for grate area56,074
Power L16572
Power MT281.07

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Wes Barris