Sentetsu Tehoro-class locomotive

The Tehoro-class (テホロ) locomotives were a class of steam tender locomotives of the Chosen Government Railway (Sentetsu) with 4-6-0 wheel arrangement.[1] 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".[2]

Chosen Government Railway Tehoro class (テホロ) Korean National Railroad Teou6 class (터우6) Korean State Railway Tŏuyu class (더우유)
A Tehoro-class locomotive as built.
Type and origin Power type Steam Builder Gyeongseong Works, Kawasaki, Hitachi Kasato, Mitsubishi Build date 1927–1942 Total produced 95
Specifications Configuration: ​  • Whyte 4-6-0 Gauge 1,435 mm (4 ft 8 ^1⁄2 in) Driver dia. 1,680 mm (66 in) Length 18,424 mm (60 ft 5.4 in) Width 3,050 mm (10 ft 0 in) Height 4,232 mm (13 ft 10.6 in) Loco weight 75.10 t (73.91 long tons) to 77.20 t (75.98 long tons) Tender weight 48.50 t (47.73 long tons) to 54.00 t (53.15 long tons) Fuel capacity 7.6 t (7.5 long tons) to 9.5 t (9.3 long tons) Water cap 17,500 L (4,600 US gal) to 20,000 L (5,300 US gal) Firebox:  • Firegrate area 4.36 m^2 (46.9 sq ft) Boiler: ​  • Small tubes 150 x 51 mm (2.0 in)  • Large tubes 24 x 137 mm (5.4 in) Boiler pressure 12.6 kgf/cm^2 (179 psi) Heating surface 170.80 m^2 (1,838.5 sq ft)  • Tubes 157.20 m^2 (1,692.1 sq ft)  • Firebox 12.00 m^2 (129.2 sq ft) Superheater: ​  • Heating area 46.30 m^2 (498.4 sq ft) Cylinders 1 Cylinder size 530 mm × 660 mm (21 in × 26 in) Valve gear Walschaerts
Performance figures Maximum speed 95 km/h (59 mph) Tractive effort 120.0 kN (27,000 lbf)
Career Operators Chosen Government Railway Korean National Railroad Korean State Railway Class Sentetsu: テホロ KNR: 터우6 KSR: 더우유 Number in class 95 Numbers Sentetsu: テホロ1–テホロ95 Delivered 1927–1942

After the Liberation of Korea, of the 178 surviving locomotives of all Teho classes - including six previously owned by private railway companies - 106 went to the Korean National Railroad in the South, and 72 to the Korean State Railway in the North.[3]

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.[1] 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.[4] These featured a single-stage compressor, 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.[1] The next thirteen came in 1929, five from Gyeongseong and four each from Mitsubishi and Hitachi's Kasato works;[1][4] the last of these became the largest producer of Tehoro class locomotives.[1] Another eighteen were delivered in 1937, nine each from Hitachi Kasato and Kawasaki,[1] 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.[4] Finally, between 1939 and 1941, 56 more were delivered, mostly from Hitachi Kasato.[1]

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.[1]

Postwar

Korean National Railroad 터우6 (Teou6) class

The exact dispersal of the Tehoko-class locomotives after the partition of Korea in 1945 and the division of Sentetsu assets in 1947 is uncertain, but at least five went to the South,[4] where the Korean National Railroad designated them 터우6 (Teou6) class [1] and used them until April 1955, when they were replaced by diesel locomotives.[5]

Known KNR 터우6-class locomotives

Number	Last Sentetsu number	Builder	Year	Notes
터우6-23	テホロ23	Hitachi Kasato	1937
터우6-25	テホロ25	Hitachi Kasato	1937	Derelict by 1954.[4]
터우6-32	テホロ32	Kawasaki	1937
터우6-82	テホロ83	Hitachi Kasato	1942
터우6-93	テホロ93	Hitachi Kasato	1942

Korean State Railway 더우유 (Tŏuyu) class

Most of the class went to the North after the partition, where they were designated 더우유 (Tŏuyu) class by the Korean State Railway, but little is known of their service lives and subsequent fates.

Construction

Year	Builder	Total	Numbers (1927–1938)	Numbers (1938–1945)
1927 July	Gyeongseong	1	751	テホロ1
1927 Oct.	Gyeongseong	1	752	テホロ2
1929 Mar.-Dec.	Gyeongseong	5	759–763	テホロ9–テホロ13
1929	Hitachi Kasato Mitsubishi	4 4	764–771	テホロ14–テホロ21
1937	Hitachi Kasato Kawasaki	9 9	772–789	テホロ22–テホロ39
1939	Hitachi Kasato	15	-	テホロ40–テホロ54
1940	Hitachi Kasato	10	-	テホロ55–テホロ64
1941	Hitachi Kasato Kawasaki	14 3	-	テホロ65–テホロ81
1942	Hitachi Kasato	14	-	テホロ82–テホロ95
Total		95

Tehoro production totals by manufacturer:[1]

Builder	Years	Total
Gyeongseong	1927, 1929	7
Kawasaki	1927, 1937, 1941	18
Hitachi Kasato	1929, 1937, 1939–42	66
Mitsubishi	1929	4
Total		95

References

1. Byeon, Seong-u (1999). 한국철도차량 100년사 [Korean Railways Rolling Stock Centennial] (in Korean). Seoul: Korea Rolling Stock Technical Corp.
2. Colvin, Fred H. (1906). The railroad pocket-book: a quick reference cyclopedia of railroad information. New York, Derry-Collard; London, Locomotive Publishing Company (US-UK co-edition). p. L‑9.
3. "Korean National RR TW-1 4-6-0". donsdepot.donrossgroup.net.
4. "Korean National RR Class TW6 4-6-0s". donsdepot.donrossgroup.net.
5. "철또군이 들려주는 이야기 : 네이버 블로그". korail0918.blog.me.