Berlin Mills Railway 7

Berlin Mills Railway 7 is a 2-4-2ST steam locomotive at Steamtown National Historic Site in Scranton, Pennsylvania. It was built in 1911 by the Vulcan Iron Works for the Berlin Mills Railway, an industrial line in Berlin, New Hampshire. Number 7 worked there as a switcher until November 1944, when it was sold to the Groveton Papers Company of Groveton, New Hampshire. In 1956, it was finally replaced by a diesel locomotive, ending 45 years of use. After a few years of idleness, though, the locomotive was leased to the Woodsville, Blackmount and Haverhill Steam Railroad, a new tourist railroad near Haverhill. It operated as the only locomotive for this company until it folded after 1963. It was ultimately donated to Steamtown by the Groveton Paper Company in 1969.

Berlin Mills Railway 7
No. 7 on static display at Steamtown National Historic Site, on April 6, 2024
Type and origin Power type Steam Builder Vulcan Iron Works Serial number 1679 Model I-15-S Build date January 1911
Specifications Configuration: ​  • Whyte 2-4-2ST  • UIC 1′B1′ n2tG Gauge 4 ft 8+1⁄2 in (1,435 mm) Leading dia. 26 in (660 mm) Driver dia. 44 in (1,118 mm) Trailing dia. 26 in (660 mm) Length 30 ft 9 in (9.37 m) Width 9 ft 10 in (3.00 m) Adhesive weight 85,000 lb (38.6 tonnes) Loco weight 115,000 lb (52.2 tonnes) Fuel type Coal Fuel capacity 2 short tons (1.8 tonnes) Water cap. 1,500 US gal (5,700 L; 1,200 imp gal) Boiler pressure 140 psi (0.97 MPa) Cylinders Two, outside Cylinder size 17 in × 24 in (432 mm × 610 mm) Valve type Slide valves
Performance figures Tractive effort 18,759 lbf (83.44 kN)
Career Operators Berlin Mills Railway, Groveton Papers Company, Woodsville, Blackmount and Haverhill Railroad Numbers 7 Locale White Mountains Region Last run 1963 Retired January 25, 1956 (revenue service) 1963 (excursion service) Preserved 1969 Restored 1962 Current owner Steamtown National Historic Site Disposition On static display