USRA Designs

USRA Mikado Steam Engine

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The Mikados

 

The USRA Mikado engine designs came in both a light and heavy version. The Light Mikado was the standard light freight locomotive of the USRA. They were considered well designed and modern, with an additional 641 copies built after the end of the USRA's control.

 

Specifications for the USRA Light Mikado and the USRA Heavy Mikado are as follows:


 

Light

Heavy

Builders

Lima, Baldwin, ALCO

same

Years Delivered

1918-1920

same

Length of Locomotive

48 ft - 7 in.

Same

Wheel Base of Locomotive

36 ft. - 1 in

Same

Wheel Base of Locomotive and Tender

71 ft. - 4-1/2 in.

71 ft. 9-1/2"

Wheel Base of Drivers

16 ft. - 9 in.

Same

Driver diameter

63 in.

Same

Leading Truck Wheels

33 in. dia.

Same

Trailing Truck Wheels

43 in dia.

Same

Locomotive Weight

290,800 lbs.

325,000 lbs

Weight on Leading Truck

20,200 lbs.

28,000 lbs

Weight on Trailing Truck

49,100 lbs.

57,100 lbs.

Weight on drivers

221,500 lbs

240,000

Factor of adhesion

4.02

3.98

Cylinders

26 x 30 in

27 x 32 in

Valve gears

Walschaert

same

Boiler pressure

200 psi

190 psi

Tubes and Flues (length)

19 ft.

same

Heating Surface, Tubes and Flues

3,497 sq. ft

3,978 sq. ft.

Heating Surface, Firebox w/ Arch Tubes

286 sq. ft

319 sq. ft

Superheater, Heating Surface

882 sq. ft

993 sq. ft.

Firebox (length x width)

114-1/8" x 84-1/4"

120-1/8" x 84-1/4"

Grate Area

66.7 sq. ft.

70.3 sq. ft.

Tractive Power (maximum)

54,700 lbs.

60,000 lbs.

Tender - water capacity

10,000 gal

same

Tender - coal capacity

16 ton.

same

(Standardized Locomotives built for the U. S. Railroad Administration by the American Locomotive Company, pamphlet No. 1004p)

 

 

The USRA Light Mikado

 

The first Light Mikado was build by Baldwin for the Baltimore and Ohio Railroad. It was completed in July 1918 and given #4500. This engine is one of few remaining Light Mikado that have survived and is currently living out its days at the Baltimore and Ohio Railroad Museum, Baltimore, MA

 

B&O Light Mikado #4500

Builder's Photograph of B&O #4500. (A 4,256 x 1,212 pixel version of this picture is here)

 

Elevation and Sections

(click on picture for a larger view)

Mikado USRA Steam Locomotive USRA Mikado Stema Locomotive

Source: 1922 Locomotive Cyclopedia of American Practice

6,037 × 2,244 image here

Source: 1922 Locomotive Cyclopedia of American Practice

 

 

 

 

 

August 23, 2015