The P-1 was a class of seven semi-steamlined 4-6-4 locomotives rebuilt by the Wabash's Decatur shops from Mikados. The first five were rebuilt from the three-cylinder class K-5 in 1943. Basically only the boiler remained nearly unchanged, while the running gear was completely new with drivers of 80 inches (2.032 mm) and only two larger cylinders. Two more were rebuilt in 1947 from K-4 locomotives. Running numbers were 700 to 706. All seven had Timken roller bearings and a light blue livery with a bright white stripe along the running boards. They remained in regular service until 1953. Only 706 was earmarked for possible preservation, but ultimately scrapped in 1956.