Verde Tunnel & Smelter 2-6-6-2 "Mallet Mogul" Locomotives in the USA
Class Details by Steve Llanso of Sweat House Media
Class MM-3 (Locobase 6766)
Data from SP 7 - 1951 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange. works numbers were 61536-61537 in February 1920.
[
] (visited 19 August 2005) notes that these Mallet Moguls originally operated on the Arizonan mining road headquartered in Jerome (which lies 100 miles north of Phoenix) and working the copper mines at Cleopatra Hill.
After 23 years, the Espee obtained the pair in 1943 to operate on Beaumont Hill near Los Angeles. Still running as compounds, they added eight years (3931) and eleven years (3930) to their service records before retirement.
The Espee diagram notes that the firebox was fitted with five thermic syphons. A Stan Kistler photograph hosted on [
] (19 August 2005) shows counterbalancing that filled half the driver disk on the third axle.
| Principal Dimensions by Steve Llanso of Middle Run Media | |
|---|---|
| Class | MM-3 |
| Locobase ID | 6766 |
| Railroad | Verde Tunnel & Smelter |
| Country | USA |
| Whyte | 2-6-6-2 |
| Number in Class | 2 |
| Road Numbers | 3930-3931 |
| Gauge | Std |
| Number Built | 2 |
| Builder | Alco-Schenectady |
| Year | 1920 |
| Valve Gear | Walschaert |
| Locomotive Length and Weight | |
| Driver Wheelbase (ft / m) | 20.67 / 6.30 |
| Engine Wheelbase (ft / m) | 48.83 / 14.88 |
| Ratio of driving wheelbase to overall engine wheelbase | 0.42 |
| Overall Wheelbase (engine & tender) (ft / m) | |
| Axle Loading (Maximum Weight per Axle) (lbs / kg) | 62,700 / 28,440 |
| Weight on Drivers (lbs / kg) | 376,000 / 170,551 |
| Engine Weight (lbs / kg) | 447,000 / 202,756 |
| Tender Loaded Weight (lbs / kg) | |
| Total Engine and Tender Weight (lbs / kg) | 447,000 |
| Tender Water Capacity (gals / ML) | |
| Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT) | |
| Minimum weight of rail (calculated) (lb/yd / kg/m) | 104 / 52 |
| Geometry Relating to Tractive Effort | |
| Driver Diameter (in / mm) | 57 / 1448 |
| Boiler Pressure (psi / kPa) | 220 / 1520 |
| High Pressure Cylinders (dia x stroke) (in / mm) | 23.5" x 32" / 597x813 |
| Low Pressure Cylinders (dia x stroke) (in / mm) | 37" x 32" / 940x813 |
| Tractive Effort (lbs / kg) | 82,623 / 37477.21 |
| Factor of Adhesion (Weight on Drivers/Tractive Effort) | 4.55 |
| Heating Ability | |
| Tubes (number - dia) (in / mm) | 225 - 2.25" / 57 |
| Flues (number - dia) (in / mm) | 40 - 5.5" / 140 |
| Flue/Tube length (ft / m) | 24 / 7.32 |
| Firebox Area (sq ft / m2) | 360 / 33.45 |
| Grate Area (sq ft / m2) | 72 / 6.69 |
| Evaporative Heating Surface (sq ft / m2) | 4907 / 456.04 |
| Superheating Surface (sq ft / m2) | 1139 / 105.86 |
| Combined Heating Surface (sq ft / m2) | 6046 / 561.90 |
| Evaporative Heating Surface/Cylinder Volume | 305.40 |
| Computations Relating to Power Output (More Information) | |
| Robert LeMassena's Power Computation | 15,840 |
| Same as above plus superheater percentage | 18,850 |
| Same as above but substitute firebox area for grate area | 94,248 |
| Power L1 | 8900 |
| Power MT | 313.10 |
Photos
- 500 (unknown photographer, photo courtesy Alexander Mitchell)
