The reference for locomotives and railcars


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Nickel Plate Road class H-6
United States | 1918 | 86 produced
H-6d No. 627 on a works photo
H-6d No. 627 on a works photo
Ron Ziel, „American Locomotives 1858 to 1949”

After the Nickel Plate Road class H-5 of 1917, the next ten H-6a were USRA Light Mikados, delivered by ALCO. In the years 1920 to 1924, Lima delivered the classes H-6b to H-6f, which were virtually identical to each other and totaled 61 units. 15 more, which were again USRA Light Mikados, came to the NKP in 1923 via the acquisition of the Lake Erie & Western and became the class H-6o.

Over time, individual Mikados were equipped with mechanical stokers and larger tenders. The fireboxes were also changed. For most of them, the service life ended in the forties. Today 587, 624 and 639 are preserved, with the 587 having been operational for a longer period since 1988.

VariantH-6aH-6b to fH-6o
Axle config2-8-2 (Mikado) 
Gauge4 ft 8 1/2 in (Standard gauge)
Dimensions and Weights
Wheelbase36 ft 1 in
Fixed wheelbase16 ft 9 in
Total wheelbase71 ft 4 1/2 in
Service weight282,000 lbs305,400 lbs282,000 lbs
Adhesive weight220,000 lbs227,600 lbs220,000 lbs
Total weight462,400 lbs660,400 lbs462,400 lbs
Axle load55,000 lbs58,500 lbs55,000 lbs
Water capacity10,000 us gal22,000 us gal10,000 us gal
Fuel capacity32,000 lbs (coal)40,000 lbs (coal)32,000 lbs (coal)
Power sourcesteam
Estimated power2,940 hp (2,192 kW)2,950 hp (2,200 kW)
Optimal speed34 mph
Starting effort54,724 lbf
Power Plant
Driver diameter63 in
Boiler pressure200 psi
Expansion typesimple
Cylinderstwo, 26 x 30 in
Grate area66.7 sq ft
Firebox area280 sq ft
Tube heating area3,464 sq ft3,497 sq ft
Evaporative heating area3,744 sq ft3,777 sq ft
Superheater area882 sq ft
Total heating area4,626 sq ft4,659 sq ft
Calculated Values
steam locomotive
last changed: 02/2024

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