Victorian Railways Dd class

This article is about the 1902 D^D class and the 1908 ${\displaystyle \mathrm {D_{E}^{D}} }$ steam locomotives. For the 1876 D class steam locomotive ("Rodgers"), see Victorian Railways D class (1876). For the 1887 D class steam locomotive, see Victorian Railways D class (1887).

This article has multiple issues. Please help improve it or discuss these issues on the talk page. (Learn how and when to remove these messages) This article may contain an excessive amount of intricate detail that may interest only a particular audience. Please help by spinning off or relocating any relevant information, and removing excessive detail that may be against Wikipedia's inclusion policy. (August 2019) (Learn how and when to remove this message) This article possibly contains original research. Please improve it by verifying the claims made and adding inline citations. Statements consisting only of original research should be removed. (August 2019) (Learn how and when to remove this message) (Learn how and when to remove this message)

Victorian Railways DD class
VR photo of DD 590 as built, 1902
Type and origin Power type Steam Builder Newport Workshops (138) Ballarat North Workshops (8) Bendigo Workshops (8) Baldwin Locomotive Works (20) Beyer, Peacock & Company (20) Walkers (20) Thompsons Ltd, Castlemaine (40) Phoenix Foundry, Ballarat (7) Serial number Phoenix: 350-356 Beyer, Peacock & Company: 5535-5554 Walkers: 197-216, Thompsons: 1-40
Specifications Configuration: ​  • Whyte 4-6-0 Gauge 5 ft 3 in (1,600 mm) Driver dia. 61 in (1.549 m) Length 57 ft 4+3⁄4 in (17.49 m) Axle load 13 long tons 0 cwt (29,100 lb or 13.2 t) Adhesive weight 38 long tons 6 cwt (85,800 lb or 38.9 t) Loco weight 53 long tons 0 cwt (118,700 lb or 53.9 t) Tender weight 41 long tons 16 cwt (93,600 lb or 42.5 t) Total weight 94 long tons 16 cwt (212,400 lb or 96.3 t) Fuel type Coal Fuel capacity 5 long tons 0 cwt (11,200 lb or 5.1 t) Water cap. 4,220 imp gal (19,200 L; 5,070 US gal) Firebox: ​  • Grate area 21.2 sq ft (1.97 m2) Boiler pressure 175 lbf/in2 (1.21 MPa) Heating surface 1,375 sq ft (127.7 m2) Cylinders Two, outside Cylinder size 18 in × 26 in (457 mm × 660 mm)
Performance figures Tractive effort 20,530 lbf (91.3 kN) at 85% boiler pressure
Career Number in class 261

The D^D class (later reclassified into D¹, D² and D³ subclasses) was a passenger and mixed traffic steam locomotive that ran on Victorian Railways from 1902 to 1974. Originally introduced on mainline express passenger services, they were quickly superseded by the much larger A² class and were relegated to secondary and branch line passenger and goods service, where they gave excellent service for the next fifty years. The D^D design was adapted into a 4-6-2T tank locomotive for suburban passenger use, the D^DE (later D⁴) class. They were the most numerous locomotive class on the VR, with a total of 261 D^D and 58 ${\displaystyle \mathrm {D_{E}^{D}} }$ locomotives built.