PRR D2

PRR D2 & D2a
Class B A #138 (later class D2a)
Power type Steam
Builder PRR Altoona Works
Build date 1868–1872 (D2);
1881–1882 (D2a)
Total produced 20 (D2); 45 (D2a)
Configuration 4-4-0
UIC classification 2′B
Gauge 4 ft 8 1⁄2 in (1,435 mm)
Leading wheel
diameter		 28 in (711 mm) (D2)[1]
30 in (762 mm) (D2a)[2]
Driver diameter 62 in (1,575 mm) (D2)[1]
68 in (1,727 mm) (D2a)[2]
Wheelbase 22 ft 5 5⁄8 in (6.85 m)[2][3]
Length 54 ft 5.44 in (16.60 m)[2][3]
Width 9 ft 0.94 in (2.77 m)[2][3]
Height 14 ft 8 in (4.47 m) (D2)[3]
14 ft 11 in (4.55 m) (D2a)[2]
Weight on drivers 52,500 lb (23.8 tonnes) (D2)[3]
53,750 lb (24.4 tonnes) (D2a)[2]
Locomotive weight 80,500 lb (36.5 tonnes) (D2)[3]
82,200 lb (37.3 tonnes) (D2a)[2]
Tender weight 51,400 lb (23.3 tonnes) (D2 & D2a)[2][3]
Locomotive & tender
combined weight		 131,900 lb (59.8 tonnes) (D2)[3]
133,600 lb (60.6 tonnes)[2]
Tender type Eight-wheel with water scoop
Fuel type Soft coal
Fuel capacity 8,000 lb (3.6 tonnes)[3]
Water capacity 2,400 US gal (9,100 l; 2,000 imp gal)[3]

The Pennsylvania Railroad's steam locomotive class D2 (formerly Class B, pre-1895) comprised twenty 4-4-0 locomotives intended for mountain passenger helper service, constructed at the railroad's own Altoona Works during 1869–1880. [4] They were the second standardized class of locomotives on the railroad and shared many parts with other standard classes.[1]

This design differed from the Class A (later D1) mainly in its smaller drivers for greater tractive effort in mountainous terrain. Like all the early standardized 4-4-0s on the PRR, the Class B had a wagon-top boiler with steam dome and a firebox between the two driving axles.

In 1881, the PRR took the Class B design and modified it to produce more locomotives for express passenger service, with 68-inch (1,727 mm) drivers like the earlier Class A. These new locomotives were designated Class B A, and were classified as B2a in the post-1895 scheme; forty-five of them were constructed.[4][5]

References

  1. ^ a b c Dredge, James (1879). The Pennsylvania Railroad. London: Engineering magazine. 
  2. ^ a b c d e f g h i j Pennsylvania Railroad. "Class D2 diagram". PRR.Railfan.net. http://prr.railfan.net/diagrams/PRRdiagrams.html?diag=d2a_oldba.gif&sel=ste&sz=sm&fr=. Retrieved 2008-08-19. 
  3. ^ a b c d e f g h i j Pennsylvania Railroad. "Class D2a diagram". PRR.Railfan.net. http://prr.railfan.net/diagrams/PRRdiagrams.html?diag=d2.gif&sel=ste&sz=sm&fr=. Retrieved 2008-08-19. 
  4. ^ a b "PRR Steam Roster". Northeast Rails. http://www.northeast.railfan.net/prr_steam2.html. Retrieved 2007-12-31. 
  5. ^ Warner, Paul T. (1924). Motive Power Development on the Pennsylvania Railroad System. Philadelphia: Baldwin Locomotive Works. 
A (0-4-0): A1 · A2 · A3 · A4 · A5s B (0-6-0): B1 (s) · B2 · B3 · B4 · B5 · B6 · B7 · B8 · B1 (e) C (0-8-0): C1 · C29 · C30 · C31
D (4-4-0): D1 · D2 · D3 · D4 · D5 · D6 · D7 · D8 · D9 · D10 · D11 · D12 · D13 · D14 · D15 · D16 · D21 · D22 · D23 · D24 · D25 · D26 · D30 · D31 · D32 · D33 · D34 · D35 · D36 · D37 · D38 · D39 · D61 · "Odd D" #10003
E (4-4-2): E1 · E2 · E3 · E4 · E5 · E6 · E7 · E21 · E22 · E23 · E28
F (2-6-0): F1 · F2 · F3 · F21 · F22 · F23 · F24 · F25 · F26 · F27 · F30 · F31 · F61
G (4-6-0): G1 · G2 · G3 · G4 · G5 · G53 H (2-8-0): H1 · H2 · H3 · H4 · H5 · H6 · H8 · H9 · H10 I (2-10-0): I1s
J (2-6-2 and 2-10-4): J1 · J28 K (4-6-2): K1 · K2 · K3s · K4s · K5 L (2-8-2): L1s · L2s · L5 · L6
M (4-8-2): M1 N (2-10-2): N1s · N2s O (4-4-4): O1
P (4-6-4): P5 Q (4-6-4-4 and 4-4-6-4): Q1 · Q2 R (4-8-4): R1
S (6-4-4-6 and 6-8-6): S1 · S2 T (4-4-4-4): T1
Articulated steam locomotives: CC1s · CC2s · HC1s · HH1s · HH2s Articulated electric locomotives: AA1 · BB1 · BB2 · BB3 · DD1 · DD2 · FF1 · FF2 · GG1 Non-standard: E2b · E2c · E3b · E44