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The Baltimore and Ohio Railroad's sole Class N-1 steam locomotive, #5600 (named "George H. Emerson"), was the first duplex locomotive and the first 4-4-4-4 locomotive ever built. It was designed and built by the Baltimore and Ohio Railroad's own Mount Clare Shops in 1937.

History[]

Beginning[]

The Baltimore and Ohio Railroad's sole Class N-1 steam locomotive, #5600 George H. Emerson, was the first duplex locomotive and the first 4-4-4-4 locomotive ever built. It was designed and built by the Baltimore and Ohio Railroad's own Mount Clare Shops in 1937.

The Design[]

The B&O's 5600 was designed in a very weird/odd way, as it was designed for its wheel arrangement to remain the same, as well as using some of the basic dimensions of a 4-8-4 "Northern" type steam locomotive.

The World Fair[]

The B&O N-1 #5600 had made an appearance at the 1939 New York World Fair, similar to the PRR S1 #6100 that would come two years later after the B&O N-1 was constructed.

The Cylinders[]

The rear set of cylinders were placed beside the firebox. This allowed the locomotive's wheelbase to remain the same. The space beside the firebox was hot and dirty, which caused premature cylinder wear, and the placement of the cylinders limited the size of the firebox.

These same problems occurred on the PRR Q1, which also placed the rear cylinders by the firebox; however it and the Q1 had problems with the sizes of the cylinders facing the other direction (or basically the rear cylinders facing back-to-front)

Withdrawal and Disposition[]

Despite how incredible the N-1 was, it did the work it was meant to do. It had ran it's final run until 1943, when the 5600 was retired from active service that same year in 1943, lingering in a scrapyard for seven years, until the single example of a duplex locomotive for the Baltimore and Ohio Railroad was sadly scrapped in 1950.

Gallery[]

List of Duplex Locomotives
France: Petiet A111A
United Kingdom: LNWR Dreadnought Class
United States: Baltimore and Ohio Class N-1Pennsylvania Railroad Class S1Pennsylvania Railroad Class T1Pennsylvania Railroad Class T1aPennsylvania Railroad Class Q1Pennsylvania Railroad Class Q2
New-Build: Pennsylvania Railroad Class T1 No. 5550
Never-built: 4-6-4-6ACE 3000New York Central C1-a
Tank Engines: Petiet A111A
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