Subclass I1sa increased maximum steam cut-off to admit steam for 78% of the piston stroke (rather than the original 50%), boosting low speed tractive effort from 90,000 to 96,000 pounds …

Dec 7, 2021 · The I1sa class was designed for freight service, and all came with piston valves, 62-inch drivers, and a boiler pressure of 250 p.s.i. as standard equipment. With a huge firebox …

#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 …

Beginning in 1930, almost all of the I1s engines were redesignated I1sa, which indicated a modification to the valves to permit running at cutoffs of up to 78%, equated to a starting …

Mar 1, 2023 · Upgrades for the largest 2-10-0 Decapod fleet. The PRR Hippos began to undergo upgrades in 1930 as the I1sa, after which most of the class received modifications of the valve …

In the late 1950's PRR I1sa's around Columbus were mostly used as hump and transfer engines. Elsewhere on the Pennsy, where these recording were taken, they were still used on the road. …

PRR #4483 is a 2-10-0 steam locomotive built in 1923 and is the last surviving Pennsylvania Railroad Class I1sa locomotive, the largest class of decapods built.

Subclass I1sa increased maximum steam cut-off to admit steam for 78% of the piston stroke (rather than the original 50%), boosting low speed tractive effort from 90000lbf96000lbf. There …

Shown here is Pennsylvania Railroad engine #4390, an I-1SA (2-10-0)

Here is a rare tender view shot of both the M-1 on the left and the I1sa on the right. Spilled coal is still evident on both the water tanks as is the "Doghouse" on the short haul tender of #4483. Its …