The Pennsylvania Railroad (PRR) N1s was a class of 2-10-2 "Santa Fe" steam locomotives built for the Pennsylvania's Lines West. 60 engines were built between December 1918 and November 1919, and worked heavy mineral freight to and from ports on the Great Lakes until their retirement in the late 1940s. All examples were scrapped by 1950.
Overview
The 2-10-2 wheel arrangement, ten driving wheels with a two-wheel leading truck and a two-wheel cast KW-pattern trailing truck under a large Belpaire firebox, suited the N1s' intended purpose well. They were drag freight engines, designed to haul heavy freight up the 0.3% grade leading out of the PRR's "Lake ports," and were rated at on these relatively easy grades. The N1s had a longer boiler at long, but the I1s used a higher working pressure of . The I1s' tractive effort was higher, at just over , but the N1s had a superior factor of adhesion—4.13 to the I1s' 3.28, suggesting the N1s had less of a tendency to slip than the Decapod. The N1s, as a low speed drag hauler, was limited to , while the I1s was capable of or greater.
Disposition
The N1s were the first class of large power withdrawn after diesel locomotives appeared, as diesels proved superior at the low-speed "lugging" the N1s was designed for. All were scrapped by 1950.
See also
- Pennsylvania Railroad I1 class
- Pennsylvania Railroad class J1
- 2-10-2