Firebox heating surface included 140 sq ft of thermic syphons and arch tubes. Developed for the Chicago-Minneapolis run (400 miles in 400 minutes) in competition with the Milwaukee Road's Hiawatha, which was pulled by either the A-class 4-4-2s or the F-7 class 4-6-4s. The C & NW locomotives were streamlined and painted green and yellow.
Their "physical attributes" were very similar to the Milwaukee's F-7s, which were also built by Alco in the same year. One striking internal difference: The E-4 had only eight 2-inch tubes, which together with the 196 3 3/4" flues, made up much of her heating surface. This ratio of tube to flue is almost as far away from the usual balance as a standard boiler could get. By comparison, the F-7s had 220 more square feet, divided among 60 2 1/4" tubes and 164 3 1/2" flues, a more typical arrangement.
Despite the difference, however, there appears to have been little difference in how these engines steamed, which underscores the custom-build tendency of steam locomotive manufacturers that ill-fitted them to compete with the standardized diesels. In fact, the E-4s were soon displaced by diesels and ran the transcontinental route from Chicago to Omaha.
| Specifications | |
|---|---|
| Class | E-4 |
| Locobase ID | 180 |
| Railroad | Chicago & North Western (C&NW) |
| Whyte | 4-6-4 |
| Road Numbers | 4001-4009 |
| Gauge | Std |
| Builder | Alco-Schenectady |
| Year | 1938 |
| Valve Gear | |
| Locomotive Length and Weight | |
| Driver Wheelbase | 14.67' |
| Engine Wheelbase | 42.33' |
| Ratio of driving wheelbase to overall engine wheebase | 0.35 |
| Overall Wheelbase (engine & tender) | 88.98' |
| Axle Loading (Maximum Weight per Axle) | |
| Weight on Drivers | 216000 lbs |
| Engine Weight | 412000 lbs |
| Tender Light Weight | 360000 lbs |
| Total Engine and Tender Weight | 772000 lbs |
| Tender Water Capacity | 20000 gals |
| Tender Fuel Capacity (oil/coal) | 25 tons |
| Minimum weight per yard of rail on which locomotive could run | 120 lb rail |
| Geometry Relating to Tractive Effort | |
| Driver Diameter | 84" |
| Boiler Pressure | 300 psi |
| Cylinders (dia x stroke) | 25" x 29" |
| Tractive Effort | 55022 lbs |
| Factor of Adhesion (Weight on Drivers/Tractive Effort) | 3.93 |
| Heating Ability | |
| Firebox Area | 507 sq. ft |
| Grate Area | 90.70 sq. ft |
| Evaporative Heating Surface | 3958 |
| Superheating Surface | 1884 |
| Combined Heating Surface | 5842 |
| Evaporative Heating Surface/Cylinder Volume | 240.23 |
| Computations Relating to Power Output (More Information) | |
| Robert LeMassena's Power Computation | 27210 |
| Same as above plus superheater percentage | 35985.02 |
| Same as above but substitute firebox area for grate area | 201151.08 |
| Power L1 | 59774.98 |
| Power MT | 1830.29 |
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