Pennsylvania Railroad 6755

Pennsylvania Railroad 6755 is a preserved M1b class 4-8-2 "Mountain" type steam locomotive built in June 1930 for the Pennsylvania Railroad by the railroad's own Altoona Works as a member of the M1b locomotive class for mainline freight service. Retired from commercial service in 1957, the locomotive was preserved by the Pennsylvania Railroad and was placed on display at the Railroad Museum of Pennsylvania in Strasburg, Pennsylvania. The No. 6755 is the only M1 class locomotive to have survived into preservation.

Pennsylvania Railroad 6755
No. 6755 on display at the Railroad Museum of Pennsylvania in 2010
Type and origin Power type Steam Builder Altoona Works Serial number 4255 Build date June 1930
Specifications Configuration: ​  • Whyte 4-8-2 Gauge 4 ft 8+1⁄2 in (1,435 mm) Driver dia. 72 in (1.829 m) Axle load 67,750 lb (30,700 kg; 30.7 t) Adhesive weight 271,000 lb (122.9 t) Loco weight 385,000 lb (174.6 t) Tender weight 378,360 lb (172,000 kg; 172 t) Total weight 768,360 lb (349,000 kg; 349 t) Tender type 210F75A "Long-haul" Fuel type Coal Fuel capacity 31 t (30.5 long tons; 34.2 short tons) Water cap. 22,020 Gallons Firebox: ​  • Grate area 69.90 sq ft (6.494 m2) Boiler pressure 270 psi (1.86 MPa) Feedwater heater Worthington Heating surface: ​  • Firebox 397 sq. ft Cylinders Two, outside Cylinder size 27 in × 30 in (686 mm × 762 mm) Valve gear Walschearts Valve type Piston
Performance figures Maximum speed 70 mph (110 km/h) Tractive effort 69,711 lbf (310.1 kN) Factor of adh. 3.89
Career Operators Pennsylvania Railroad Class M1b Numbers PRR 6755 Retired 1957 Current owner Pennsylvania Historical and Museum Commission Disposition On static display

Locomotive No. 6755
U.S. National Register of Historic Places
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Nearest city	Strasburg, Pennsylvania
Coordinates	39°58′56″N 76°9′40″W
Area	less than one acre
Built	1930
Architect	Pennsylvania Railroad
Architectural style	dual service
MPS	Pennsylvania Railroad Rolling Stock TR
NRHP reference No.	01000519[1]
Added to NRHP	December 17, 1979

History

Main article: PRR M1

The No. 6755 was built by the Altoona Works in June 1930. The 6755 was a class M1a and was used predominantly in freight service, though it would occasionally be used for passenger trains. In 1953, the locomotive went back to the Altoona Works and was rebuilt into a class M1b. The locomotive continued to be used for freight service until 1957, when it was retired from the roster.

Present status

The No. 6755 is on static display at the Railroad Museum of Pennsylvania in Strasburg, Pennsylvania.^[2] The No. 6755 has since been deteriorating at a rapid pace, with its boiler jackets removed in the early 2000s. Prolonged exposure to the elements has wreaked havoc on major parts of the locomotive, causing structural rust. The No. 6755 is one of the locomotives the museum plans to place inside the roundhouse currently under construction as of July 2025.^[3]

Gallery

• 
  On display at the Railroad Museum of Pennsylvania
• 
  The attached coal tender.

See also

NYC 3001- This is the New York Central Railroad's version of the M1 that survives. Just like the 6755, the 3001 was a dual-service locomotive.