The latter 20 (numbered 1570-1589 from the start) came from Baldwin in 1926 (works numbers 58922, 58950, 58964-58966 in January, 59052-59058 in March, 59110-59113 in April, 59174-59177 in May).
Known as "Simple Simons" or "Simons" (according to C&O Power) because they operated as simple-expansion articulateds, unlike the earlier compound Mallets. Firebox had combustion chamber that added 145 sq ft (13.45 sq m) to direct heating surface area and the boiler had an Elesco K-54 feed water heater. When delivered, boilers were pressed at 205 psi. All four cylinders were supplied through 12" (305 mm) piston valves.
The Baldwin H-7as were credited with slightly higher weight on drivers, larger heating surface (6,580 sq ft). Cylinder horsepower for all was 4,092 hp.
By 1935, all of the H-7s were fitted with several thermic syphons that contributed a total of 165 sq ft (15.3 sq m) to the direct heating surface area. The result is shown in the specifications.
Alexander (American Locomotives, 1950) notes that H7 pulled 9,500-ton trains over 113-mile run from Russell, Kentucky to Columbus, Ohio in 5 hours. Averaged 4,400 miles per month until displaced by the 2-10-4s in Ohio and the 2-6-6-6 Alleghenies in the rest of the territory. 30 of the fifty were later leased to the Union Pacific. By then the fireboxes had been fitted with 167 sq ft of thermic syphon as shown in the specs.
|Principal Dimensions by Steve Llanso of Sweat House Media|
|Railroad||Chesapeake & Ohio (C&O)|
|Number in Class||45|
|Road Numbers||1100-1124/1540-1564, 1570-1589|
|Locomotive Length and Weight|
|Driver Wheelbase (ft / m)||15.75 / 4.80|
|Engine Wheelbase (ft / m)||58.08 / 17.70|
|Ratio of driving wheelbase to overall engine wheebase||0.27|
|Overall Wheelbase (engine & tender) (ft / m)||104.70 / 31.91|
|Axle Loading (Maximum Weight per Axle) (lbs / kg)||65,200 / 29,574|
|Weight on Drivers (lbs / kg)||493,070 / 223,653|
|Engine Weight (lbs / kg)||567,500 / 257,414|
|Tender Loaded Weight (lbs / kg)||376,340 / 170,705|
|Total Engine and Tender Weight (lbs / kg)||943,840 / 428,119|
|Tender Water Capacity (gals / ML)||21,000 / 79.55|
|Tender Fuel Capacity (oil/coal) (gals/tons / ML/MT)||25 / 22.70|
|Minimum weight of rail (calculated) (lb/yd / kg/m)||103 / 51.50|
|Geometry Relating to Tractive Effort|
|Driver Diameter (in / mm)||57 / 1448|
|Boiler Pressure (psi / kPa)||215 / 14.80|
|High Pressure Cylinders (dia x stroke) (in / mm)||23" x 32" / 584x813 (4)|
|Tractive Effort (lbs / kg)||108,547 / 49236.15|
|Factor of Adhesion (Weight on Drivers/Tractive Effort)||4.54|
|Firebox Area (sq ft / m2)||632 / 58.71|
|Grate Area (sq ft / m2)||112.20 / 10.42|
|Evaporative Heating Surface (sq ft / m2)||6580 / 611.30|
|Superheating Surface (sq ft / m2)||1849 / 171.78|
|Combined Heating Surface (sq ft / m2)||8429 / 783.08|
|Evaporative Heating Surface/Cylinder Volume||213.80|
|Computations Relating to Power Output (More Information)|
|Robert LeMassena's Power Computation||24,123|
|Same as above plus superheater percentage||29,430|
|Same as above but substitute firebox area for grate area||165,774|