Alaska Railroad 2-8-2 "Mikado" Locomotives in the USA

The U. S. Government bought the Alaska Northern Railroad in 1914 and extended the road Northward to Fairbanks. In the same year the name was changed to Alaska Railroad. The Alaska Railroad ran from Seward and Whittier, in the south of Alaska to Fairbanks, and beyond to Eielson Air Force Base and Fort Wainwright in the interior of that state. It carries freight and passengers between those three cities and to many destinations between them, including Anchorage and Denali National Park. The railroad has a mainline of 470 miles.

The railroad is connected to the lower 48 via three rail barges that sail between the Port of Whittier and Harbor Island in Seattle but does not currently have a fixed land connection with any other railroad lines on the North American network.

In 1933, the Alaska began running seasonal passenger trains two times a week between Seward and Anchorage, 114 miles, and between Anchorage and Fairbanks, 356 miles. The State of Alaska bought the railroad from the US government in 1985 and continued running its seasonal passenger trains.

The Alaska Railroad bought three "Mikado" type locomotives from the Baldwin Locomotive Works during 1927 and 1928. These locomotives were assigned road numbers 701 through 703. Numbers 701 and 702, delivered in 1927, had 54" diameter drivers, 22" x 28" cylinders, a 200 psi boiler pressure, they exerted 42,600 pounds of tractive effort and each weighed 244,400 pounds. Number 703, delivered in 1928, was very similar to numbers 701 and 702 but had a 210 psi boiler pressure, which meant it exerted 44,800 pounds of tractive effort. Number 703 weighed 244,120 pounds.

All three locomotives had a firebox area of 246 square feet. The evaporative surface was 2,718 square feet and with the superheater had a combined heating surface of 3,339 square feet.

Two other "Mikado" Type locomotives were added to the roster during 1942-1943. The Alaska Railroad bought two second hand locomotives from the Northern Pacific. They were former NP numbers 1676 and 1692.

There are no surviving Alaska Railroad 2-8-2 "Mikado" type locomotives.


Qty.Road NumbersYear BuiltFrom Other RRYear AcquiredBuilderNotes
17511910Northern Pacific1942ALCO3
1 7521910Northern Pacific1943ALCO4
  1. Numbers 701 and 702 retired in 1954 and then sold to Forrocarrilles Langreo, Spain in 1958
  2. Number 703 retired in 1954 and then sold to Forrocarrilles Langreo, Spain in 1958
  3. Number 751 purchased second hand from the Northern Pacific in 1942. Former NP number 1676. Number 751scrapped in 1947.
  4. Number 752 purchased second hand from the Northern Pacific in 1943. Former NP number 1692. Number 752 scrapped in 1947.

Class Details by Steve Llanso of Sweat House Media

Class 700 (Locobase 6427)

Data from [] (visited 22 December 2004). See also DeGolyer, Vol 77, pp. 800+. (Thanks to Chris Hohl for his 8 August 2016 reporting the original boiler pressure on 701-702 and booster TE.) Works numbers were 59605-59606 in October 1926, 60689 in December 1928.

This trio of Mikados faced "extreme cold and heavy snow" and would be cresting at aptly named Summit, Alaska's high point of 2,350 feet (716 metres).

The 700s used 13" (330 mm) piston valves and had fireboxes fitted wth four American Security arch tubes contributing 25 sq ft (2.3 sq m) to the direct heating surface area in addition to 37 sq ft (3.45 sq m) of combustion chamber area. According to the Baldwin specs, any extra heating help would be welcome because the "low grade soft coal" yielded a modest 10,500 to 12,000 BTU per pound.

Chris Hohl notes that the first two locomotives were delivered with their boilers set to 200 psi. The Alaska Railroad diagram and the Baldwin specs beginning at p. 806 shows that the setting on the 703 was 210 psi (13.8 bar), which translated to a starting tractive effort of 44,800 lb (20,321 kg). Booster tractive effort for all three was 11,800 lb (5,352 kg).

These were among the first locomotives to be purchased new by the ARR and they served in steam into the 1950s. In 1954, all three were sold to Spain's FC Langreo. Apparently none of these ever actually went into service and were scrapped soon after their arrival.

Principal Dimensions by Steve Llanso of Sweat House Media
Locobase ID6427
RailroadAlaska Railroad
Number in Class3
Road Numbers701-703
Number Built3
Valve GearBaker
Locomotive Length and Weight
Driver Wheelbase (ft / m)14.50 / 4.42
Engine Wheelbase (ft / m)33.17 / 10.11
Ratio of driving wheelbase to overall engine wheebase 0.44
Overall Wheelbase (engine & tender) (ft / m)68.08 / 20.75
Axle Loading (Maximum Weight per Axle) (lbs / kg)46,500 / 21,092
Weight on Drivers (lbs / kg)175,680 / 79,687
Engine Weight (lbs / kg)244,120 / 110,731
Tender Loaded Weight (lbs / kg)197,280 / 89,485
Total Engine and Tender Weight (lbs / kg)441,400 / 200,216
Tender Water Capacity (gals / ML)10,000 / 37.88
Tender Fuel Capacity (oil/coal) (gals/tons / ML/MT)14 / 12.70
Minimum weight of rail (calculated) (lb/yd / kg/m)73 / 36.50
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)54 / 1372
Boiler Pressure (psi / kPa)200 / 13.80
High Pressure Cylinders (dia x stroke) (in / mm)22" x 28" / 559x711
Tractive Effort (lbs / kg)42,664 / 19352.09
Factor of Adhesion (Weight on Drivers/Tractive Effort) 4.12
Heating Ability
Firebox Area (sq ft / m2)246 / 22.85
Grate Area (sq ft / m2)57.70 / 5.36
Evaporative Heating Surface (sq ft / m2)2718 / 252.51
Superheating Surface (sq ft / m2)621 / 57.69
Combined Heating Surface (sq ft / m2)3339 / 310.20
Evaporative Heating Surface/Cylinder Volume220.63
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation11,540
Same as above plus superheater percentage13,733
Same as above but substitute firebox area for grate area58,548
Power L113,935
Power MT699.48

  • 701 (James Sava Photo)
  • 702 (Unknown photographer)
  • 751 (Unknown photographer)
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Wes Barris