Nickel Plate Road (NKP) No. 172 was a Class L1a 4-6-4 "Hudson" steam locomotive. It was built in 1927 by ALCO for the Nickel Plate Road.
This special Hudson was used to haul heavy passenger trains and freight trains on the Nickel Plate Road railroad.
No. 172 remained in service until 1956 when it was retired from service and later sold for scrap.