Baltimore and Ohio 4500

Baltimore and Ohio 4500
B&O 4500 as it was built in 1918
Type and origin Power type Steam Builder Baldwin Locomotive Works Serial number 49153 Build date July 4, 1918
Specifications Configuration: ​  • Whyte 2-8-2  • UIC 1′D2′ h1 Gauge 4 ft 8+1⁄2 in (1,435 mm) standard gauge Leading dia. 33 in (838 mm) Driver dia. 63 in (1,600 mm) Trailing dia. 43 in (1,092 mm) Wheelbase Loco & tender: 41.98 ft (12.80 m) Axle load 55,200 lb (25,000 kilograms; 25.0 metric tons) Adhesive weight 220,000 lb (100,000 kilograms; 100 metric tons) Loco weight 292,000 lb (132,000 kilograms; 132 metric tons) Tender weight 185,400 lb (84,100 kilograms; 84.1 metric tons) Total weight 477,400 lb (216,500 kilograms; 216.5 metric tons) Fuel type Coal Fuel capacity 16 t (16 long tons; 18 short tons) Water cap. 10,000 US gal (38,000 L; 8,300 imp gal) Firebox: ​  • Grate area 66.70 sq ft (6.197 m2) Boiler pressure 200 lbf/in2 (1.38 MPa) Heating surface: ​  • Firebox 286 sq ft (26.6 m2) Superheater: ​  • Heating area 882 sq ft (81.9 m2) Cylinders Two Cylinder size 26 in × 30 in (660 mm × 762 mm) Valve gear Walschaert
Performance figures Tractive effort 53,800 lbf (239.31 kN) Factor of adh. 4.08
Career Operators Baltimore and Ohio Class Q-3 Number in class 1st of 100 Numbers B&O 4500 B&O 300 (from 1957-1964) Retired August 1957 Preserved 1960 Current owner B&O Railroad Museum Disposition On static display

Baltimore and Ohio 4500 is a 2-8-2 "USRA Light Mikado" steam locomotive built by the Baldwin Locomotive Works in Philadelphia, Pennsylvania in July 1918 for the Baltimore and Ohio Railroad (B&O) as a member of the Q-3 class.

The locomotive hauled freight for the B&O until retirement in August 1957 and was donated for display at the B&O Railroad Museum in Baltimore, Maryland. It is the sole surviving Baltimore and Ohio Mikado type steam locomotive.