PRR K-4s No. 3847 appears here at Englewood Union Station, Chicago, on October 1, 1949 in an image contributed by Carl Weber. The poppet valves applied to this locomotive enabled a more precise timing of steam admission to the cylinders, and exhaust therefrom, than did conventional gears such as the Baker or Walschaert, and hence improved the performance of steam locomotives especially at higher speeds. However, they were difficult to maintain because they had smaller, less accessible parts and because most railroad shop personnel were not familiar with them. No. 3847 also received a front-end throttle and type HT stoker during its rebuild, and displays the other modernization features described for No. 3674. Amazingly, this locomotive appears several times in the Green Frog DVD The Golden Twilight of Postwar Steam, Part 1.