The Pennsylvania Railroad no. 1320 was a single experimental passenger three-cylinder compound

2-2-2-0 Under the Whyte notation for the classification of steam locomotives, 2-2-2-0 usually represents the wheel arrangement of two leading wheels on one axle, four powered but uncoupled driving wheels on two axles, and no trailing wheels, but can also be ...

locomotive purchased by the

Pennsylvania Railroad The Pennsylvania Railroad (reporting mark PRR), legal name The Pennsylvania Railroad Company also known as the "Pennsy", was an American Class I railroad that was established in 1846 and headquartered in Philadelphia, Pennsylvania. It was named ...

in 1889, based on the London & North Western Railway's Dreadnought class, designed by Francis Webb. As the London & North Western's Crewe Works, which had built the Dreadnought classes, was not legally allowed to sell its locomotives, 1320 was instead constructed by

Beyer, Peacock & Company Beyer, Peacock and Company was an English railway locomotive manufacturer with a factory in Openshaw, Manchester. Founded by Charles Beyer, Richard Peacock and Henry Robertson, it traded from 1854 until 1966. The company exported locomotives, ...

Manchester Manchester () is a city in Greater Manchester, England. It had a population of 552,000 in 2021. It is bordered by the Cheshire Plain to the south, the Pennines to the north and east, and the neighbouring city of Salford to the west. The t ...

to the Dreadnought's specifications.

Oswald Nock Oswald Stevens Nock, B. Sc., DIC, C. Eng, M.I.C.E., M.I.Mech.E., M.I.Loco.E., (21 January 1905 – 29 September 1994), nicknamed Ossie, was a British railway signal engineer and senior manager at the Westinghouse company; he is well know ...

, et al. Railways at the Turn of the Century, 1895-1905. Blandford P., 1969.

Design

The design featured a boiler pressed to delivering saturated steam to two outside high-pressure cylinders, which exhausted to one low-pressure cylinder inside the frames. All three cylinders had a stroke of ; the high-pressure cylinders drove the rear wheels, while the low-pressure drove the leading driving wheels. As the two pairs of driving wheels were not connected, the locomotives were "

duplex drive DD or Duplex Drive tanks, nicknamed "Donald Duck tanks", were a type of amphibious swimming tank developed by the British during the Second World War. The phrase is mostly used for the Duplex Drive variant of the M4 Sherman medium tank, that was ...

" or "double-singles". The locomotive performed poorly for the Pennsylvania, being slow and weak compared to the road's other, domestically purchased locomotives, as well as unsuited to the rougher trackage common of U.S. railroads. The unique design of the cylinders made the locomotive difficult to operate and maintain, making it unpopular among the road's engineers and management staff. The locomotive was scrapped in 1897.

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References

External links

Picture of this locomotive (ETH Zurich)
{{PRR locomotives Beyer, Peacock locomotives Compound locomotives Duplex locomotives Individual locomotives of the United States Pennsylvania Railroad locomotives Railway locomotives introduced in 1889 Standard gauge locomotives of the United States Steam locomotives of the United States 2-2-2-0 locomotives