PRR I1s #4483 is on display at the Western New York Railroad Historical Society in Hamburg, NY

PRR I1s #4483, Hamburg, NY

#4483 is stored at the Western New York Railroad Historical Society’s work site in Hamburg, NY. It is one of the Pennsylvania Railroad's class I1s steam locomotives, which were the largest of the Decapod type (2-10-0) in the US, weighing 366,500 lbs, 334,500 lbs on their 62” drivers.

Five hundred and ninety-eight were built between 1916 and 1923, one hundred and twenty-three at Pennsy's Altoona shops and four hundred and seventy-five at the Baldwin Locomotive Works. They were the main
freight haulers on the Pennsy until WWII, and worked until the end of steam on the system
in 1957.


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PRR I1s #4483, HamburgPRR I1s #4483, HamburgPRR I1s #4483, Hamburg
PRR I1s #4483, HamburgPRR I1s #4483, Hamburg

Nicknames given to the I1s type included “Decs” and “Hippos”, the latter because of their large boilers. These limited the size of the driving wheels, which made it impossible to mount counterweights large enough to balance the piston thrusts. As a result, they were hard riding at anything but low speeds and prone to slipping, and not popular with crews.

Of the five sets of drivers, only the first and last had flanges, which reduced the engine’s minimum curve radius. The driver wheelbase is 22’ 8” and engine wheelbase 32’ 2”.

PRR I1s #4483, HamburgPRR I1s #4483, Hamburg
PRR I1s #4483, Hamburg

#4483 was built by the Baldwin Locomotive Works in Eddystone, PA, in 1923, converted to an I1sa in 1931 and then assigned to the Pennsy’s Eastern Region, Susquehanna Division and Northern Region. In 1944, it was reassigned to the Eastern Region, Central PA Division and Williamsport Division.

The locomotive was retired in 1957 and became part of the Pennsy's historic locomotive collection stored at Northumberland, PA, most of which later went to the Railroad Museum of Pennsylvania in Strasburg, PA.

PRR I1s #4483, HamburgPRR I1s #4483, Hamburg

Many I1s locomotives were converted to I1sa types during major overhauls, increasing maximum steam cut-off to admit steam for 78% of the piston stroke rather than 50%. Low speed tractive effort rose from 90,000 lbs to 96,000 lbs.

The rebuild increased engine weight to 386,100 lbs, 352,500 lbs on the drivers. The grate stayed at 69.9 sq ft, but the firebox increased from 312 sq ft to 322 sq ft, including a 90 sq ft combustion chamber and 31 sq ft of fire tubes. The I1sa was mated to a tender weighing 204,700 lbs light with a 10,300 gallon water and 18.7 ton coal capacity.

PRR I1s #4483, Hamburg
PRR I1s #4483, HamburgPRR I1s #4483, Hamburg

In 1963, the Pennsy
sold #4483 to the Westinghouse Air
Brake Company to display on the front lawn of their headquarters in Pittsburgh, PA.

In 1982, it was bought by the Western New York Railroad Historical Society.

PRR I1s #4483, HamburgPRR I1s #4483, HamburgPRR I1s #4483, HamburgPRR I1s #4483, HamburgPRR I1s #4483, HamburgPRR I1s #4483, HamburgPRR I1s #4483, Hamburg