Pennsylvania Railroad class D7

Specifications
Specifications
Configuration:;
• Whyte	4-4-0
• UIC	2′B
Gauge	4 ft 8+1⁄2 in (1,435 mm)
Leading dia.	30 in (762 mm) (D7); 33 in (838 mm) (D7a)
Driver dia.	68 in (1,727 mm) (D7); 62 in (1,575 mm) (D7a)
Wheelbase	22 ft 7+1⁄2 in (6.90 m)
Length	58 ft 0.6 in (17.69 m)
Height	14 ft 4 in (4.37 m)
Axle load	32,650 lb (14.8 tonnes)
Adhesive weight	56,700 lb (25.7 tonnes) (D7) ; 58,700 lb (26.6 tonnes)
Loco weight	93,500 lb (42.4 tonnes) (D7); 96,330 lb (43.7 tonnes) (D7a)
Total weight	160,880 lb (73.0 tonnes)
Fuel type	Anthracite coal
Fuel capacity	12,000 lb (5.4 tonnes)
Water cap.	2,400 US gal (9,100 L; 2,000 imp gal)
Firebox:
• Grate area	34.75 sq ft (3.23 m2)
Boiler pressure	140 lbf/in2 (970 kPa)
Heating surface:
• Firebox	155 sq ft (14.40 m2)
• Tubes	1,134 sq ft (105.35 m2)
• Total surface	1,289 sq ft (119.75 m2)
Cylinders	2
Cylinder size	17 in × 24 in (432 mm × 610 mm)
Valve gear	Stephenson
Valve type	Slide valves

Type and origin
Type and origin
Power type	Steam
Builder	PRR Altoona Works
Build date	1882–1891
Total produced	58 D7, 61 D7a

Pennsylvania Railroad D7
Pennsylvania Railroad D7
	PRR D7a #953 in its builders' portrait
Power type
Type and origin
Power type	Steam
Builder	PRR Altoona Works
Build date	1882–1891
Total produced	58 D7, 61 D7a
Configuration:;
Specifications
Configuration:;
• Whyte	4-4-0
• UIC	2′B
Gauge	4 ft 8+1⁄2 in (1,435 mm)
Leading dia.	30 in (762 mm) (D7); 33 in (838 mm) (D7a)
Driver dia.	68 in (1,727 mm) (D7); 62 in (1,575 mm) (D7a)
Wheelbase	22 ft 7+1⁄2 in (6.90 m)
Length	58 ft 0.6 in (17.69 m)
Height	14 ft 4 in (4.37 m)
Axle load	32,650 lb (14.8 tonnes)
Adhesive weight	56,700 lb (25.7 tonnes) (D7) ; 58,700 lb (26.6 tonnes)
Loco weight	93,500 lb (42.4 tonnes) (D7); 96,330 lb (43.7 tonnes) (D7a)
Total weight	160,880 lb (73.0 tonnes)
Fuel type	Anthracite coal
Fuel capacity	12,000 lb (5.4 tonnes)
Water cap.	2,400 US gal (9,100 L; 2,000 imp gal)
Firebox:
• Grate area	34.75 sq ft (3.23 m2)
Boiler pressure	140 lbf/in2 (970 kPa)
Heating surface:
• Firebox	155 sq ft (14.40 m2)
• Tubes	1,134 sq ft (105.35 m2)
• Total surface	1,289 sq ft (119.75 m2)
Cylinders	2
Cylinder size	17 in × 24 in (432 mm × 610 mm)
Valve gear	Stephenson
Valve type	Slide valves
Tractive effort
Performance figures
Tractive effort	12,138 lbf (53.99 kN) (D7); 13,313 lbf (59.22 kN) (D6a)
Factor of adh.	4.7 (D7) 4.4 (D7a)

Class D7 (formerly Class A (anthracite), pre-1895) on the Pennsylvania Railroad was a class of 4-4-0 steam locomotive.^[4] Fifty-eight were built by the PRR's Altoona Works (now owned by Norfolk Southern) between 1882–1891 with 68 in (1.73 m) drivers, while sixty-one of class D7a were constructed with 62 in (1.57 m) drivers.^[1]

The D7 was fundamentally an anthracite-burning version of the PRR D6, with a larger fire-grate in order to burn the slower-burning, harder coal.^[5]

References

^ ^a ^b ^c ^d ^e "PRR Steam Roster". Northeast Rails. Retrieved 2007-12-31.
^ ^a ^b ^c ^d ^e Pennsylvania Railroad. "D7 Diagram". PRR.Railfan.net. Retrieved 2008-08-17.
^ ^a ^b ^c ^d ^e ^f ^g ^h ⁱ ^j ^k ^l ^m ⁿ ^o ^p ^q ^r Pennsylvania Railroad. "D7a Diagram". PRR.Railfan.net. Retrieved 2008-08-17.
^ Staufer, Alvin F. & Pennypacker, Bert (1962). Pennsy Power: Steam and Electric Locomotives of the Pennsylvania Railroad, 1900–1957. Staufer. LCCN 62020878.
^ Warner, Paul T. (1924). Motive Power Development on the Pennsylvania railroad System. Philadelphia: Baldwin.

[prr-roster-1] "PRR Steam Roster". Northeast Rails. Retrieved 2007-12-31.

[d7diagram-2] Pennsylvania Railroad. "D7 Diagram". PRR.Railfan.net. Retrieved 2008-08-17.

[d7adiagram-3] ^ ^a ^b ^c ^d ^e ^f ^g ^h ⁱ ^j ^k ^l ^m ⁿ ^o ^p ^q ^r Pennsylvania Railroad. "D7a Diagram". PRR.Railfan.net. Retrieved 2008-08-17.

[pennsypower-4] Staufer, Alvin F. & Pennypacker, Bert (1962). Pennsy Power: Steam and Electric Locomotives of the Pennsylvania Railroad, 1900–1957. Staufer. LCCN 62020878.

[warner-5] Warner, Paul T. (1924). Motive Power Development on the Pennsylvania railroad System. Philadelphia: Baldwin.

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