The reference for locomotives and railcars
Philadelphia & Reading “Pennsylvania”
United States | 1863 | only one produced

The “Pennsylvania” of the Philadelphia & Reading wasn't only the biggest of the camelbacks designed by James Milholland, but also the biggest locomotive in the world when it was completed in 1863. It was a 0-12-0 that was used as pusher on the steep Falls Grade near Philadelphia, Pennsylvania.

A special feature of this locomotive was that it didn't have a tender, but wasn't a real tank locomotive either. This meant that it had no coal bunker and no water tank, but was stoked before each of the short climbs. Since it was found out that the freight cars of the time couldn't handle the forces of this massive locomotive, it was rebuilt in 1870. It now had only five axles, a tender and a new cab.

Axle config0-12-0T (Twelve-coupled) 
Gauge4 ft 8 1/2 in (Standard gauge)
Dimensions and Weights
Wheelbase19 ft 7 in
Fixed wheelbase19 ft 7 in
Service weight110,250 lbs
Adhesive weight110,250 lbs
Axle load18,375 lbs
Fuel capacitycoal
Power sourcesteam
Estimated power500 hp (373 kW)
Optimal speed16 mph
Starting effort20,558 lbf
Power Plant
Driver diameter43 in
Boiler pressure100 psi
Expansion typesimple
Cylinderstwo, 20 x 26 in
Grate area31.5 sq ft
Firebox area198 sq ft
Tube heating area1,230 sq ft
Evaporative heating area1,428 sq ft
Total heating area1,428 sq ft
Calculated Values
steam locomotive
tank locomotive
James Milholland
last changed: 04/2024

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