Fremont, Elkhorn & Missouri Valley 4-8-0 "Mastodon" Locomotives of the USA

Class Details by Steve Llanso of Sweat House Media

Class G (Locobase 5431)

Data from "A Twelve-wheel Narrow-Gauge Locomotive," Railroad and Engineering Journal, Vol 65, No 6 (June 1891), p. 247. See also the thread begun by "Joes Lines" on 16 December 2009 at the BigBlueTrains forum,, last accessed 9 February 2009. Works numbers were 3421-3422 in 1891, 3703 in 1892, 26610 in May 1902, and 27601 in October.

This twelve-wheeler was described as the first of its wheel arrangement for the narrow gauge. In the R&EJ report, the adhesive weight is given as 66,000 lb (29,337 kg), which delivered a low factor of adhesion.The FE & MV ran from Fremont, Nebraska to Norfolk, on to Fort Robinson, then into the Black Hills. Although the prognosis for success of this design was quite positive, as it always was in these journals, very few if any 4-8-0s actually ran in US narrow-gauge service. Still, in addition to the 1891 pair, the FE&MV ordered another a year later, and two more a decade later in 1902.

In this particular instance, the locomotives wound up on the Chicago & North Western Railway when that enterprise formally took over the FE&MV in 1903. They were numbered 1298-1303. Locobase isn't clear on what the C&NW did to limit tractive effort to 18,200 lb (8,255 kg), possibly resorting to early cutoff. Given the adhesion weight shown in the C&NW diagram books,however, the factor of adhesion still calculated as less than 3.

Specifications by Steve Llanso of Sweat House Media
Locobase ID5431
RailroadFremont, Elkhorn & Missouri Valley (C&NW)
Number in Class2
Road Numbers208-212/1298-1302
Number Built2
Valve GearStephenson
Locomotive Length and Weight
Driver Wheelbase10.17'
Engine Wheelbase18'
Ratio of driving wheelbase to overall engine wheebase 0.56
Overall Wheelbase (engine & tender)
Axle Loading (Maximum Weight per Axle)
Weight on Drivers54000 lbs
Engine Weight66000 lbs
Tender Light Weight47000 lbs
Total Engine and Tender Weight113000 lbs
Tender Water Capacity2100 gals
Tender Fuel Capacity (oil/coal)3.5 tons
Minimum weight of rail (calculated)23 lb/yard
Geometry Relating to Tractive Effort
Driver Diameter37"
Boiler Pressure160 psi
Cylinders (dia x stroke)16" x 24"
Tractive Effort22583 lbs
Factor of Adhesion (Weight on Drivers/Tractive Effort) 2.39
Heating Ability
Firebox Area90 sq. ft
Grate Area14.40 sq. ft
Evaporative Heating Surface963 sq. ft
Superheating Surface
Combined Heating Surface963 sq. ft
Evaporative Heating Surface/Cylinder Volume172.42
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation2304
Same as above plus superheater percentage2304
Same as above but substitute firebox area for grate area14400
Power L12496
Power MT407.61


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