Đường sắt Nhà nước Triều Tiên vận hành nhiều loại đầu máy điện, diesel và hơi nước, cùng với nhiều loại tàu chở khách động lực phân tán. Các đầu máy của KSR được lấy từ nhiều nguồn khác nhau. Phần lớn, chủ yếu là đầu máy hơi nước và điện do Nhật Bản sản xuất, đã bị bỏ lại sau khi kết thúc thời kỳ thuộc địa, và các đầu máy này đã di chuyển phần lớn các chuyến tàu giữa thời điểm phân chia Triều Tiên và bắt đầu Chiến tranh Triều Tiên.[29] Vào ngày 10 tháng 12 năm 1947, Kukch'ŏl có 786 đầu máy - 617 đầu máy khổ tiêu chuẩn (141 tank, 476 tender), 158 đầu máy khổ hẹp, 8 đầu máy điện (khổ tiêu chuẩn), và ba cần cẩu hơi nước;[93] kể từ tháng 9/1945, 747 toa chở khách, 6,928 toa chở hàng và 29 tàu điện ở miền Bắc - tất cả những thứ này đã được thừa hưởng từ Chosen Government Railway và các công ty đường sắt thuộc sở hữu tư nhân khác nhau ở Triều Tiên.[93]

The Korean War destroyed much of the North's railway infrastructure, but with extensive Soviet và Chinese aid, along with aid from the rest of the Eastern Bloc - mostly in the form of steam locomotives from Hungary, Czechoslovakia, Poland và Romania, North Korea's railways were rapidly rebuilt. During the Ch'ŏllima Movement, North Korea's equivalent to China's Great Leap Forward,[94] Kim Il-sung placed a special emphasis on the electrification of the railways. As a result of this emphasis, many hundreds of kilometres of railway were electrified by the end of the 1950s.[95]

Another important aspect of the Ch'ŏllima Movement was the further industrialisation of North Korea. In terms of industry, the Japanese legacy was a fairly extensive network of railways connecting steel mills, chemical plants and other heavy industries with the many mines of the north - coal, iron, and many other metal and non-metal resources; all of these were further expanded during the 1950s. In 1945, a rolling stock repair facility in P'yŏngyang,[96] eventually becoming today's Kim Chong-t'ae Electric Locomotive Works, which has manufactured almost all of North Korea's electric locomotives since the first Red Flag 1-class locomotive, North Korea's first domestically produced electric locomotive, was rolled out in 1961.[39]

With ample coal supplies to fire steam locomotives, and electrification of the rail network being expanded rapidly after the Korean War, dieselisation was not the priority for Kukch'ŏl that it was for many other railways, not starting in earnest until the second half of the 1960s with the arrival of the first diesel locomotives from Hungary and the Soviet Union. Once there, though, they have consistently shared the burden with electric and steam locomotives, taking over the latter's share of work on non-electrified lines gradually.[29] Though still in sporadic use, steam had mostly left the North Korean mainlines by the end of the 1970s,[39] and elsewhere by the end of the 1990s.

Severe floods in the 1990s had taken their toll on North Korea's hydroelectric generation system, and even some mines had flooded - and due to electricity shortages caused by the silting of the dams, there was often little electricity available to run pumps needed to clear the water out of the mines. By the turn of the millennium, Kukch'ŏl was having difficulties keeping electric trains running, and the fleet of K62s was insufficient to meet the transportation needs, even though demand had been reduced significantly due to ongoing economic difficulties. To alleviate this problem, more M62s from several European countries, along with a sizeable number of second-hand locomotives from China, were imported.[29] At the same time, however, the economic crisis also made it difficult to obtain diesel fuel, and by the late 1990s rail traffic was barely plodding along.

In recent years, extensive work has begun on refurbishing the rail network and power generation capabilities in the country, but diesels continue to play their significant role in hauling passenger and freight trains on the various mainlines, and Kim Jong-un has been placing special emphasis on the refurbishment and modernisation of the railways.[97] Due to ongoing economic difficulties in North Korea, maintenance levels are poor; locomotive serviceability is estimated at 50%.[98] However, recent imports of diesel locomotives from China and construction of newer electric locomotive types are helping to ameliorate the situation.[39]

At the present time the Đường sắt Nhà nước Triều Tiên operates primarily using electric and diesel power, with a wide array of locomotive types. Most numerous and important are the Red Flag 1-class electrics, the Red Flag 6-class articulated electrics for heavy freight trains, and the Kanghaenggun-class electrics, which were converted from diesels; also important are the K62-class diesels, and the various types imported recently from China. Efforts to modernise the motive power stock are also underway, with the continuing construction of Red Flag 5400-class heavy electrics and the latest addition, the Sŏngun Red Flag-class electrics designed to provide greater performance with lower power consumption,[99] along with a program to modernise the K62 diesels with new engines and other upgrades.[100]

Năm 2002, những toa chở khách do Thụy Sĩ sản xuất được mua lại từ BLS Lötschbergbahn đã được đưa vào phục vụ trên tàu cao tốc P'yŏngyang–Hyesan, trở thành những toa chở khách đầu tiên do phương Tây sản xuất được vận hành bởi Kukch'ŏl.[29]

Theo chỉ đạo của Kim Jong-un để cải thiện hình ảnh của đường sắt Triều Tiên,[101] Những toa chở khách màu xanh lá cây đồng đều của Kukch'ŏl's đang được sơn lại thành sặc sỡ hơn.