Sentetsu Purena-class locomotives

The プレナ (Purena) class locomotive was designed by the Railway Bureau based on the experiences gained through the design of modifications leading to the Pureshi-class rebuilds, and differed considerably from the imported Pure classes.[3] The first eight were built for a private railway, with Hitachi's Kasato factory[3] and Kawasaki[4] each building four units; these were bought by Sentetsu in 1936 and numbered 341-348.[5]

The design was then modified to include a superheater, but the resulting design retained the "Purena" classification; the two subclasses were thenceforward referred to as the "Original Purena" and "Bureau Purena" (局プリナ) classes. The first six Bureau Purena locomotives were built for Sentetsu in 1931 by the Gyeongseong Works;[3] these were numbered 321 through 326.[5] The 14 locomotives of both Purena subtypes were lumped together in Sentetsu's general renumbering of 1938, with 341–348 becoming プレナ1 through プレナ8, and 321–326 becoming プレナ9 through プレナ14.[5] In 1938 four more were built by Nippon Sharyō and fourteen more were built at Gyeongseong. In 1939 and 1941,[4] a total of nine were built by Kawasaki and Hitachi Kasato for the Gyeongchun Railway;[3] these were assembled in Korea at Sentetsu's Busan shops and numbered プレナ85 through プレナ93.

Nineteen locomotives of the Sentetsu Purena design were built for the South Manchuria Railway (Mantetsu) in Japan in 1935.[6] Although under the Mantetsu classification system tank locomotives were generally given the "Dabu" (ダブ, from "double-ender") classification,[7] Mantetsu instead designated these as プレサ (Puresa) class; eight were assigned to Mantetsu's Rajin depot for use on the North Chosen Line, whilst the other ten were assigned to depots in Manchukuo.

Many Purena class locomotives ended up with the Korean National Railroad after Liberation, which designated them 푸러7 (Pureo7) class;[3] at least 15 are known to have been operated by the KNR.[5]

The Sentetsu Purena class locomotives that remained in the North after the partition of Korea were operated by the Korean State Railway, designating them 부러치 (Purŏch'i) class, and later renumbering them into the 1700 series around the early 1970s. Three examples, numbers 1709, 1718, and 1720, were operational at the steelworks in Ch'ŏngjin as of November 2019, being used for tourist events.[8]

The nine Puresa-class locomotives that Mantetsu had assigned to its Rajin depot were taken over by the Korean State Railway after the war. They were initially designated 부러서 (Purŏsŏ) class - together with the Puresa-class engines inherited from Sentetsu - and were retained in use mostly around Rajin; around the early 1970s, they were renumbered into the 1300 series, though at least one's number omitted the initial '1'.[9] At least two have been seen operational in the 21st century; one, 1304, was seen in 2001 doing shunting work at Ch'ŏngjin,[9] while the other, 1319, is still operational as of October 2015, kept in pristine condition for use with tourist and railfan trains.[10]

The one unit known to have omitted the initial '1', number 307, was inspected by Kim Jong-il as a child at Rajin Station on 6 September 1954.[11] This locomotive has also been depicted on a commemorative stamp issued by the DPRK postal service.[9]

The ten Puresa-class engines that were used by Mantetsu in Manchukuo were taken over first by the joint Chinese-Soviet "Chinese Changchun Railway" (Chinese: 中國長春鐵路, Zhōngguó Chǎngchūn Tiělù; Russian: Кита́йская Чанчу́ньская желе́зная доро́га, Kitayskaya Chanchun'skaya Zheleznaya doroga), which took over Mantetsu operations within China in 1945. In 1952, the Chinese Changchun Railway was returned to China,[12] and they were taken over by the China Railway as class ㄆㄌ3. In 1959, they were designated class PL3, numbered 51–60.[13]