Pennsylvania Railroad class D5

4 ft 8+1⁄2 in (1,435 mm)Leading dia.26 in (660 mm)^[1]Driver dia.56 in (1,422 mm)^[1]Wheelbase19 ft 9.6 in (6.04 m) (locomotive);
40 ft 6.1 in (12.35 m) (with tender)^[1]Length49 ft 6.2 in (15.09 m) (locomotive and tender)^[1]Width8 ft 10+1⁄2 in (2.71 m) (cab roof)^[1]Height14 ft 8 in (4.47 m) (rail to top of stack)^[1]Adhesive weight40,800 lb (18.5 tonnes)^[1]Loco weight65,200 lb (29.6 tonnes)^[1]Tender weight40,800 lb (18.5 tonnes)^[1]Total weight106,000 lb (48.1 tonnes)^[1]Fuel capacity6,500 lb (2.9 tonnes)^[1]Water cap.1,600 US gal (6,100 L; 1,300 imp gal)^[1]

The Pennsylvania Railroad's steam locomotive class D5 (formerly Class G, pre-1895) comprised eighteen lightweight 4-4-0 locomotives for light duty, maintenance-of-way and branch-line service, constructed at the railroad's own Altoona Works (now owned by Norfolk Southern) during 1870–1873.^[2]

They shared many parts with other standard classes, although less so with the heavy 4-4-0s on account of their lighter build; instead, they shared some components with 0-6-0 switcher classes F and H (later B1 and B2).^[3] The Class G locomotives had a straight-topped boiler, unlike the wagon-top of the other 4-4-0 classes.