Class of locomotives
The 500 series locomotives are a group of diesel-electric and diesel-hydraulic locomotives bought either new or second-hand by the Korean State Railway from the Soviet Union and Russia. The series includes several types of locomotive, all numbered in the 내연5xx range. The exact assignment of running numbers is not known, nor is the total number of units imported - or even all the types included in this series. However, the following are known:
Some second hand broad gauge () units are operation around Rajin since the conversion of the Hongŭi Line from Tumangang on the DPRK-Russia border to Hongŭi, and of a section of the Hambuk Line from Hongŭi to Rajin to dual (standard and broad) gauge, completed in 2013.
References.
 ;templatestyles src="Reflist/styles.css" / ;