The Tehoro-class (テホロ) locomotives were a class of

steam Steam is a substance containing water in the gas phase, and sometimes also an aerosol of liquid water droplets, or air. This may occur due to evaporation or due to boiling, where heat is applied until water reaches the enthalpy of vaporizat ...

tender locomotive A tender or coal-car (US only) is a special rail vehicle hauled by a steam locomotive containing its fuel (wood, coal, oil or torrefied biomass) and water. Steam locomotives consume large quantities of water compared to the quantity of fuel, s ...

s of the Chosen Government Railway (''Sentetsu'') with

4-6-0 A 4-6-0 steam locomotive, under the Whyte notation for the classification of steam locomotives by wheel arrangement, has four leading wheels on two axles in a leading bogie and six powered and coupled driving wheels on three axles with the absenc ...

wheel arrangement In rail transport, a wheel arrangement or wheel configuration is a system of classifying the way in which wheels are distributed under a locomotive. Several notations exist to describe the wheel assemblies of a locomotive by type, position, and ...

. The "Teho" name came from the American naming system for steam locomotives, under which locomotives with 4-6-0 wheel arrangement were called "Ten Wheeler". After the

Liberation of Korea The surrender of the Empire of Japan in World War II was announced by Emperor Hirohito on 15 August and formally signed on 2 September 1945, bringing the war's hostilities to a close. By the end of July 1945, the Imperial Japanese Nav ...

, of the 178 surviving locomotives of all Teho classes - including six previously owned by private railway companies - 106 went to the

Korean National Railroad The Korea Railroad Corporation (Korean: 한국철도공사, Hanja: ), branded as KORAIL (코레일, officially changed to in November 2019), is the national railway operator in South Korea. Currently, KORAIL is a public corporation, manage ...

in the

South South is one of the cardinal directions or compass points. The direction is the opposite of north and is perpendicular to both east and west. Etymology The word ''south'' comes from Old English ''sūþ'', from earlier Proto-Germanic ''*sunþa ...

, and 72 to the

Korean State Railway The Korean State Railway (), commonly called the State Rail () is the operating arm of the Ministry of Railways of North Korea and has its headquarters at P'yŏngyang. The current Minister of Railways is Chang Jun Song. History 1945–195 ...

in the

North North is one of the four compass points or cardinal directions. It is the opposite of south and is perpendicular to east and west. ''North'' is a noun, adjective, or adverb indicating direction or geography. Etymology The word ''no ...

Description

Having become indispensable on branchline use, it was decided to modernise the Teho type, and in 1925–26 local engineers developed a derivative locomotive. The result was the テホロ (''Tehoro'') class, the first of which was built in July 1927 and the second in October of the same year, both at Sentetsu's Gyeongseong Works. These featured a single-stage

compressor A compressor is a mechanical device that increases the pressure of a gas by reducing its volume. An air compressor is a specific type of gas compressor. Compressors are similar to pumps: both increase the pressure on a fluid and both can trans ...

, and improvements included the expansion of the heat transfer area, improved power transfer and brakes, an automated smoke box door, and other improvements. The Tehoro class was designed for use on both passenger and freight trains, and was used primarily on the Gyeongui and Gyeongbu lines. The next thirteen came in 1929, five from Gyeongseong and four each from

Mitsubishi The is a group of autonomous Japanese multinational companies in a variety of industries. Founded by Yatarō Iwasaki in 1870, the Mitsubishi Group historically descended from the Mitsubishi zaibatsu, a unified company which existed from 187 ...

and

Hitachi () is a Japanese multinational corporation, multinational Conglomerate (company), conglomerate corporation headquartered in Chiyoda, Tokyo, Japan. It is the parent company of the Hitachi Group (''Hitachi Gurūpu'') and had formed part of the Ni ...

's Kasato works; the last of these became the largest producer of Tehoro class locomotives. Another eighteen were delivered in 1937, nine each from Hitachi Kasato and

Kawasaki Kawasaki ( ja, 川崎, Kawasaki, river peninsula, links=no) may refer to: Places *Kawasaki, Kanagawa, a Japanese city **Kawasaki-ku, Kawasaki, a ward in Kawasaki, Kanagawa **Kawasaki City Todoroki Arena **Kawasaki Stadium, a multi-sport stadium *K ...

, and in 1938, as part of Sentetsu's general renumbering, the Tehoro class locomotives in service received numbers テホロ1 through テホロ39. Finally, between 1939 and 1941, 56 more were delivered, mostly from Hitachi Kasato. The Tehoro class was a notable milestone in the history of Korea's railways. As the first type designed and produced entirely by domestic (Korean and Japanese) factories, it gave Japanese and Korean designers extensive experience which was subsequently applied to the development of the Pashishi and Mikasa-class locomotives.

Postwar

Korean National Railroad 터우6 (Teou6) class

The exact dispersal of the Tehoko-class locomotives after the

partition of Korea The division of Korea began with the defeat of Japan in World War II. During the war, the Allied leaders considered the question of Korea's future after Japan's surrender in the war. The leaders reached an understanding that Korea would be l ...

in 1945 and the division of Sentetsu assets in 1947 is uncertain, but at least five went to the

, where the

designated them 터우6 (''Teou6'') class and used them until April 1955, when they were replaced by diesel locomotives.

Korean State Railway 더우유 (Tŏuyu) class

Most of the class went to the

after the partition, where they were designated 더우유 (''Tŏuyu'') class by the

, but little is known of their service lives and subsequent fates.

Construction

References

{{DPRKloco Locomotives of Korea Locomotives of South Korea Locomotives of North Korea Railway locomotives introduced in 1927 4-6-0 locomotives Gyeongseong Works locomotives Hitachi locomotives Kawasaki locomotives Mitsubishi locomotives