The JNR Class DD12 was a diesel-electric locomotive operated by the Japanese National Railways from 1946 to 1972.
History[]
The DD12 was a series of small switcher locomotives built by General Electric as part of their 47-ton "Drop Cab" switcher locomotives, of which a total of 58 locomotives were built. With the plans that Allied Forces would be stationed in Japan after World War II, the Allied Powers had expected Japan's rail network to be unable to function due to the numerous air raids carried out on the country, and to solve this issue, the Allied Powers would produce their own locomotives for use on Japan's rail network with the intention of leaving them there for use by other parties.
It would be decided that a total of thirteen locomotives would be transferred to Japan; these included six existing 47-ton switchers already in use in the Philippines to be converted to narrow gauge and two new-build 47-ton switchers. These were designated the US Army Class 8500 and numbered 8584 through 8589, 8592 and 8593. When the Allied Powers arrived in Japan, they discovered that the Japanese rail network was not as badly impacted as expected, and as a result efforts were focused on maintaining and operating these existing systems with existing vehicles and thus no more new locomotives were ordered from GE.
Equipment for 13 locomotives arrived at Yokohama Port in April 1946, with eight locomotives assembled at Ōmiya Works in May that year; the other five locomotives were never assembled and it is not known what happened to them afterwards. The locomotives were stationed at Yokohama, Takatori and Kure. While the locomotives were slow, they were considered extremely rugged and reliable and far superior than the other diesel locomotives the JNR had been prototyping around that time; these locomotives are credited for the spread of diesel locomotives in Japan. Their control equipment was said to be of a foolproof design that even a low-ranking soldier could operate these locomotives after a short training session; however because their motors were mounted low and their bogies were small, their prime movers were prone to failure after heavy rain.
The US Army withdrew the locomotives from their service in 1952, with the locomotives reclassified and renumbered under a temporary numbering scheme (e.g. DE8584, DE8585 etc.), before they were then handed off to various Japanese railway companies in 1956. JNR received five locomotives, which were reclassified Class DD12 and renumbered DD12 1 through 5, the Nagoya Railroad received two locomotives, which were reclassified the Class DED8500 but retained their original numbers (8584, 8589), while the Yawata Steel Works received one locomotive, 8587, where it was renumbered D402.
The JNR locomotives would initially be stationed in Tokyo before moving to Hiroshima, Kure, Shinagawa and Kurihama; the locomotives would perform light switching duties as well as transporting fuel to US Army bases. By 1969 the locomotives were largely replaced by the DD13 in their duties; by 1972, when fuel transporting duties had decreased significantly the locomotives were sent to Shin-Tsurumi Depot and taken out of service, abandoned on a siding at Chigasaki Depot; all locomotives were scrapped by around 1974.
The DED8500s would be used for freight services towards Komaki and Gifu Air Bases; after some use on the Kakamigahara Line the locomotives were moved to the Chikkō Line, replacing steam locomotives and domestically-manufactured diesel locomotives that were prone to failure. The locomotives were withdrawn in 1965 with the opening of the Nagoya Rinkai Railway and they were resold to the Philippines in 1966, where they operated until about December 1978. D402 would operate at the Yawata Steel Works until it was scrapped in March 1967.
No Class DD12s have been preserved.
Design[]
The DD12 featured an appearance very similar to GE's other switcher locomotives.
Specifications[]
Essentially a GE 47-ton switcher converted to narrow gauge, the DD12s were powered by two Caterpillar D17000 V8 prime movers
Template:MeitetsuMotivePower