The 1960s were a breakthrough decade for North Korea.
With the reconstruction of damage caused by the Korean War nearly complete, great advances were being made under the Ch'ŏllima Movement, the North Korean equivalent of China's Great Leap Forward; the efforts were both focussed on and aided by the railways.
Development was also aided by the fact that, during the colonial era, most Japanese construction of heavy industry including machine manufacturing, as well as the bulk of railway development, took place in the north of the country; the DPRK was also blessed with an abundance of natural resources and a number of large hydroelectric power plants that had also been built by the Japanese.
Much of the work done on the railways in this period was focussed on the electrification of trunk lines.
Due to the increased importance placed on the railways, by 1965 Kukch'ŏl was transferred from the Ministry of Transport to a newly established Ministry of Railways (조선 민주주의 인민 공화국 철도성, Chosŏn Minjujuŭi Inmin Konghwaguk Ch'ŏldosŏng).

Re-electrification of the Yangdŏk–Ch'ŏnsŏng section of the P'yŏngra Line, which had been initially electrified in 1948 but destroyed during the Korean War, was completed with Soviet assistance on 25 May 1956, but the large-scale electrification of North Korea's rail lines began only in 1958; by the end of the 1960s, nearly 900 km (560 mi) of lines had been electrified, and by 1973, when the electrification of the P'yŏngra Line was completed, over 1,300 km (810 mi) of lines had been electrified, realising the goal of electrifying all major trunk lines.
Electrification of the lines was accompanied by the manufacture of electric locomotives.
Domestic production of small electric locomotives for use in mines had begun in 1958, but production of mainline electric locomotives didn't start until a few years later.
Although the USSR had promised to deliver Soviet-made electric locomotives to North Korea, this never took place, so to supplement the sixteen electric locomotives inherited from Sentetsu, in 1958 Kukch'ŏl ordered ten Type 22E₂ locomotives from the Škoda Works of Czechoslovakia.
This was just a temporary measure, however, as the main goal was the development of a domestically-produced electric locomotive.
To this end, a licence to build the Škoda Type 30E was bought from Czechoslovakia, including technology transfer, and a number were built to the original design to gain familiarity with the process, but most of the effort was placed on designing the larger, indigenous design.
The prototype of the DPRK's first domestically produced mainline electric locomotive, the Red Flag 1, was completed at the Kim Chŏng-t'ae Works (then called the P'yŏngyang Electric Locomotive Works) on 30 August 1961, and Kim Il-sung visited the plant for the occasion and chose the locomotive's name personally.
Serial production started in 1962, with twenty built that year, followed by another thirty in 1963; eventually, over 150 were built.

Meanwhile, in order to modernise on non-electrified lines, Kukch'ŏl started ordering diesel locomotives to begin replacing steam power on these lines.
The first step towards dieselisation came in 1964, with the arrival of fourteen DVM-4-type locomotives from Ganz-MÁVAG of Hungary, which were used both for shunting and to pull local trains on branchlines.
After this positive initial experience with diesel power, an order was placed for larger, more powerful locomotives suitable for use on heavy mainline trains.
Made in the USSR to meet a Hungarian requirement, the first two prototypes of the M62-type locomotives appeared on Soviet Railways in 1964 before series production and deliveries to Hungary began in 1965; by the time Kukch'ŏl received their first deliveries of the type - designated K62-class by the factory - in 1967, the M62 had become the backbone of diesel power all over the Comecon world: in addition to Hungary, in 1965 and 1966 the type was put in service in large numbers in Poland, Czechoslovakia, and East Germany.
A total of 64 were delivered to North Korea between 1967 and 1974,
The 1960s were a breakthrough decade for North Korea. With the reconstruction of damage caused by the Korean War nearly complete, great advances were being made under the Ch'ŏllima Movement, the North Korean equivalent of China's Great Leap Forward; the efforts were both focussed on and aided by the railways. Development was also aided by the fact that, during the colonial era, most Japanese construction of heavy industry including machine manufacturing, as well as the bulk of railway development, took place in the north of the country; the DPRK was also blessed with an abundance of natural resources and a number of large hydroelectric power plants that had also been built by the Japanese. Much of the work done on the railways in this period was focussed on the electrification of trunk lines. Due to the increased importance placed on the railways, by 1965 Kukch'ŏl was transferred from the Ministry of Transport to a newly established Ministry of Railways (조선 민주주의 인민 공화국 철도성, Chosŏn Minjujuŭi Inmin Konghwaguk Ch'ŏldosŏng).
Re-electrification of the Yangdŏk–Ch'ŏnsŏng section of the P'yŏngra Line, which had been initially electrified in 1948 but destroyed during the Korean War, was completed with Soviet assistance on 25 May 1956, but the large-scale electrification of North Korea's rail lines began only in 1958; by the end of the 1960s, nearly 900 km (560 mi) of lines had been electrified, and by 1973, when the electrification of the P'yŏngra Line was completed, over 1,300 km (810 mi) of lines had been electrified, realising the goal of electrifying all major trunk lines. Electrification of the lines was accompanied by the manufacture of electric locomotives. Domestic production of small electric locomotives for use in mines had begun in 1958, but production of mainline electric locomotives didn't start until a few years later. Although the USSR had promised to deliver Soviet-made electric locomotives to North Korea, this never took place, so to supplement the sixteen electric locomotives inherited from Sentetsu, in 1958 Kukch'ŏl ordered ten Type 22E₂ locomotives from the Škoda Works of Czechoslovakia. This was just a temporary measure, however, as the main goal was the development of a domestically-produced electric locomotive. To this end, a licence to build the Škoda Type 30E was bought from Czechoslovakia, including technology transfer, and a number were built to the original design to gain familiarity with the process, but most of the effort was placed on designing the larger, indigenous design. The prototype of the DPRK's first domestically produced mainline electric locomotive, the Red Flag 1, was completed at the Kim Chŏng-t'ae Works (then called the P'yŏngyang Electric Locomotive Works) on 30 August 1961, and Kim Il-sung visited the plant for the occasion and chose the locomotive's name personally. Serial production started in 1962, with twenty built that year, followed by another thirty in 1963; eventually, over 150 were built.
Meanwhile, in order to modernise on non-electrified lines, Kukch'ŏl started ordering diesel locomotives to begin replacing steam power on these lines. The first step towards dieselisation came in 1964, with the arrival of fourteen DVM-4-type locomotives from Ganz-MÁVAG of Hungary, which were used both for shunting and to pull local trains on branchlines. After this positive initial experience with diesel power, an order was placed for larger, more powerful locomotives suitable for use on heavy mainline trains. Made in the USSR to meet a Hungarian requirement, the first two prototypes of the M62-type locomotives appeared on Soviet Railways in 1964 before series production and deliveries to Hungary began in 1965; by the time Kukch'ŏl received their first deliveries of the type - designated K62-class by the factory - in 1967, the M62 had become the backbone of diesel power all over the Comecon world: in addition to Hungary, in 1965 and 1966 the type was put in service in large numbers in Poland, Czechoslovakia, and East Germany. A total of 64 were delivered to North Korea between 1967 and 1974,
Korean State Railway