Data from C&IM 4 -1954 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange. See also DeGolyer, Volume 77, pp. 726+, 732+; and George Drury, Guide to North American Steam Locomotives (Waukesha, WI: Kalmbach Books, 1993, rev. ed. 2015), p. 117. (Thanks to Chris Hohl for his 6 May 2020 email reporting the original tender coal capacity and loaded weight and the driver diameter.) Works numbers were 60064-60065 in June 1927 and 60590 in August 1928.
The Baldwin specs addressed a service that ran on 90 lb/yard (45 kg/metre) rail, met 16 deg curves, and scaled 2% grades. Originally delivered with 63" (1,600 mm) drivers and tenders weighing 95,500 lb (43,318 kg) when carrying 8 tons of coal (7.3 metric tons), the engines acquired thicker tires and larger tenders.
George Drury wrote that these were the last three Americans built for any railroad in North America. Yet, as Drury notes, this purchase wasn't a fluke. The railroad still ran a Springfield-Peoria passenger service daily and even upgraded its passenger car fleet by buying six steel passenger cars. The three "light, modern, efficient" locomotives "were all that was necessary for C&IM's two- and three- car trains" on the schedule, according to Drury, and could even be double-headed in a pinch.
By the late 1940s, passenger traffic had withered and 501 was sold for scrap. The last passenger train ran in 1953 and the surviving pair of 4-4-0s went to the scrapyard as well.
| Principal Dimensions by Steve Llanso of Middle Run Media | |
|---|---|
| Class | A-1 |
| Locobase ID | 7651 |
| Railroad | Chicago & Illinois Midland (C&IM) |
| Country | USA |
| Whyte | 4-4-0 |
| Number in Class | 3 |
| Road Numbers | 500-502 |
| Gauge | Std |
| Number Built | 3 |
| Builder | Baldwin |
| Year | 1927 |
| Valve Gear | Walschaert |
| Locomotive Length and Weight | |
| Driver Wheelbase (ft / m) | 7 / 2.13 |
| Engine Wheelbase (ft / m) | 21.33 / 6.50 |
| Ratio of driving wheelbase to overall engine wheelbase | 0.33 |
| Overall Wheelbase (engine & tender) (ft / m) | 47.92 / 14.61 |
| Axle Loading (Maximum Weight per Axle) (lbs / kg) | |
| Weight on Drivers (lbs / kg) | 77,400 / 35,108 |
| Engine Weight (lbs / kg) | 118,400 / 53,705 |
| Tender Loaded Weight (lbs / kg) | 109,960 / 49,877 |
| Total Engine and Tender Weight (lbs / kg) | 228,360 / 103,582 |
| Tender Water Capacity (gals / ML) | 4500 / 17.05 |
| Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT) | 10 / 9 |
| Minimum weight of rail (calculated) (lb/yd / kg/m) | 65 / 32.50 |
| Geometry Relating to Tractive Effort | |
| Driver Diameter (in / mm) | 64 / 1626 |
| Boiler Pressure (psi / kPa) | 180 / 1240 |
| High Pressure Cylinders (dia x stroke) (in / mm) | 18" x 24" / 457x610 |
| Tractive Effort (lbs / kg) | 18,590 / 8432.29 |
| Factor of Adhesion (Weight on Drivers/Tractive Effort) | 4.16 |
| Heating Ability | |
| Tubes (number - dia) (in / mm) | 121 - 2" / 51 |
| Flues (number - dia) (in / mm) | 18 - 5.375" / 137 |
| Flue/Tube length (ft / m) | 12 / 3.66 |
| Firebox Area (sq ft / m2) | 113 / 10.50 |
| Grate Area (sq ft / m2) | 21.70 / 2.02 |
| Evaporative Heating Surface (sq ft / m2) | 1170 / 108.70 |
| Superheating Surface (sq ft / m2) | 242 / 22.48 |
| Combined Heating Surface (sq ft / m2) | 1412 / 131.18 |
| Evaporative Heating Surface/Cylinder Volume | 165.49 |
| Computations Relating to Power Output (More Information) | |
| Robert LeMassena's Power Computation | 3906 |
| Same as above plus superheater percentage | 4570 |
| Same as above but substitute firebox area for grate area | 23,798 |
| Power L1 | 10,627 |
| Power MT | 605.39 |