The first railway line on the Korean peninsula was built to standard (1435mm.) gauge and opened in 1899. Japanese influence in Korea was already growing and would become almost total after Japan defeated Russia in 1905. Five years later, Japan formally annexed Korea as a colony. Recognising the strategic importance of railways, the main lines were built, owned, and operated by the government but secondary railways were left to private enterprise to promote.
Excluding a short, and short-lived, 610mm. gauge line in the southern port city of Busan, which opened in 1909 using two Andrew Barclay 0-4-0 tank locomotives, early interest was concentrated in the northern part of the peninsula where the forests, coal and ore reserves all attracted the interest of light railway promoters. The southern part of the peninsula was predominantly agricultural, with fewer resources to entice railway promoters. A step change came in 1916, when the Chosen Light Railway Company started building a 762mm. gauge line eastwards from the city of Daegu in the south east towards Gyeongju, with branches from there, north to Pohang and south to Ulsan, a total route length of 110km. when completed in 1921. In 1928 this line was absorbed into the state system and by 1940 had been re-gauged to 1435mm.
In 1923 six separate, small railway companies, including the Chosen Light Railway, by this time re-named, merged to form the Chosen Railways Company (not to be confused with the state-owned Chosen Government Railway, or Sentetsu). This was the largest private railway company in the country and while it remained both a fraction the size of the state railway, and a collection of separate lines rather than a coherent system, henceforward it would play the leading role in the development of new narrow gauge railways on the peninsula. With one significant exception, these would all be in what became North Korea after 1945.
In the late 1920s a new company, the Chosen Keitoespecially as most private railway promoters in the south opted for the standard gauge. Cost was presumably one factor – the company had paid up capital of 900,000 yen (roughly £4m. at today’s prices), even then a modest amount for a line that would eventually extend to 125km. in length; another was probably a degree of realism about the likely traffic levels.
