| Pennsylvania Railroad J1 | 
|---|
|  | 
| | Type and origin | 
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 | Power type | Steam | 
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 | Builder | PRR Altoona Works | 
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 | Build date | 1942–1944 | 
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 | Total produced | 125 | 
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 | 
| | Specifications | 
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 | Configuration: 
 |  | 
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 | • Whyte | 2-10-4 | 
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 | • UIC | 1′E2′ h | 
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 | Gauge | 4 ft 8+1⁄2 in (1,435 mm) | 
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 | Driver dia. | 69 in (1.753 m), later 70 in (1.778 m) | 
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 | Length | 117 ft 8 in (35.86 m) | 
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 | Width | 11 ft 3 in (3.43 m) | 
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 | Height | 16 ft 5.5 in (5.02 m) | 
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 | Adhesive weight | 377,800 lb (171.4 t) | 
|---|
 | Loco weight | J-1 class: 589,975 lb (267.6 t) J-1a class: 579,975 lb (263.1 t)
 | 
|---|
 | Tender weight | 411,500 lb (186.7 t) | 
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 | Total weight | J-1 class: 1,001,475 lb (454.3 t) J-1a class: 991,475 lb (449.7 t)
 | 
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 | Tender type | Coast-to-Coast | 
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 | Fuel type | Coal | 
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 | Fuel capacity | 60,000 lb (27.2 t) | 
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 | Water cap. | 21,000 US gal (79,000 L; 17,000 imp gal) | 
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 | Firebox: |  | 
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 | • Grate area | 122 sq ft (11.3 m2) | 
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 | Boiler | 106 in (2,692 mm) | 
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 | Boiler pressure | 270 psi (1.86 MPa) | 
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 | Cylinders | Two | 
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 | Cylinder size | 29 in × 34 in (737 mm × 864 mm) | 
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 | Valve gear | Baker | 
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 | 
| | Performance figures | 
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 | Maximum speed | 50 mph | 
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 | Power output | 5,644 hp (4,209 kW) | 
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 | Tractive effort | 95,100 lbf (423.0 kN) Booster: 15,000 lb (6.8 t)
 Loco w/Booster: 110,100 lb (49.9 t)
 | 
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 | 
| | Career | 
|---|
 | Numbers | 6150–6174, 6401–6500 | 
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 | Nicknames | War Babies | 
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 | Locale | Pennsylvania Railroad | 
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 | Retired | 1958-1959 | 
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 | Scrapped | 1958-1959 | 
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 | Disposition | All scrapped Number 6435 rumored to be buried
 | 
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 | 
The PRR J1 was a class of 2-10-4 "Texas" type steam locomotives built between 1942 and 1944. The J1 had over 95,000 pounds-force (422.6 kN) of tractive effort, plus an additional 15,000 lbf (66.7 kN) if the booster engine was used.