PRR Q2
Pennsylvania Railroad class Q2
PRR Q2 prototype #6131 [1] |
Type and origin |
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Power type |
Steam |
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Builder |
PRR Altoona shops |
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Build date |
1944–45[1] |
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Total produced |
26[1] |
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Specifications |
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Configuration |
4-4-6-4[1] |
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UIC class |
2'BC2' |
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Gauge |
4 ft 8 1⁄2 in (1,435 mm) standard gauge[1] |
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Leading dia |
36 in (0.914 m)[1] |
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Driver diameter |
69 in (1.753 m)[1] |
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Wheelbase |
26 ft 4.5 in (8.039 m) (driving) 20 ft 4 in (6.20 m) (rigid) 53 ft 5.5 in (16.294 m) (locomotive) 107 ft 7.5 in (32.804 m) (locomotive and tender)[1] |
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Length |
124 ft 7.125 in (37.976 m) (locomotive and tender)[1] |
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Width |
11 ft 4 in (3.45 m) (storm windows open)[1] |
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Height |
16 ft 5.5 in (5.017 m)[1] |
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Adhesive weight |
393,000 lb (178,000 kg)[1] |
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Loco weight |
619,100 lb (280,800 kg)[1] |
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Tender weight |
430,000 lb (195,000 kg)[1] |
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Loco & tender weight |
1,049,100 lb (475,900 kg)[1] |
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Tender type |
PRR class 180F84, 8 axles, with conductor "doghouse" |
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Fuel type |
Soft coal |
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Fuel capacity |
39.86 short tons (36.16 t; 35.59 long tons)[1] |
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Water cap |
19,020 US gal (72,000 l; 15,840 imp gal)[1] |
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Boiler pressure |
300 psi (2.1 MPa) |
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Front cylinder |
19 3⁄4 in × 28 in (502 mm × 711 mm) |
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Rear cylinder |
23 3⁄4 in × 29 in (603 mm × 737 mm) |
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Performance figures |
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Power output |
7,987 hp (5,956 kW)[1] |
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Front angle view of a Q2.
The Pennsylvania Railroad's class Q2 comprised one prototype and twenty-five production duplex steam locomotives of 4-4-6-4 wheel arrangement.[1][2][3]
They were the largest non-articulated locomotives ever built and the most powerful locomotives ever static tested, producing 7,987 cylinder horsepower (5,956 kW) on the PRR's static test plant. They were by far the most successful duplex type. The duplex propensity to slip was combated by an automatic slip control mechanism that reduced power to the slipping unit.
The Q2 locomotive was 78% more powerful than the locomotives that PRR had in service at the time, and the company claimed the Q2 could pull 125 freight cars at a speed of 50 mph (80 km/h). [4]
Despite overall success, the Q2s were all out of service by 1951. With dieselization, they were the obvious first targets to be withdrawn since they were only a little more capable than the conventional J1 class 2-10-4s but with far higher operating and maintenance costs.
References
- 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 Harley, E.T. (1982). Classic Power 5: Pennsy Q Class. Hicksville, New York: N.J. International. ISBN 0-934088-09-8.
- ↑ Staufer, Alvin (1962). Pennsy Power. Staufer. pp. 216–225. LOC 62-20872.
- ↑ Brian Reed (June 1972). Loco Profile 24: Pennsylvania Duplexii. Windsor, Berkshire, UK: Profile Publications.
- ↑ "4-Cylinder Engine Has 78% More Power." Popular Mechanics, December 1944, p. 13.