At present, China's railway industry has been developing with great momentum. Many parts of the country have realized the electrification of the universal speed railway, and most cities have opened high-speed railway. In addition, China's electric locomotives, subways and bullet trains have been successfully exported. However, have you noticed that the qinghai-tibet railway has always used the diesel locomotive introduced from the United States? It can be said that without the American diesel locomotive, the qinghai-tibet railway may not be open to traffic on time.

The qinghai-tibet railway is a single-track railway from xining to Lhasa built by China, covering a total distance of 1,956 kilometers. The railway from golmud to Lhasa started construction in 2001 and was completed and opened to traffic in 2006. This is of great strategic significance. On the route from golmud to Lhasa, ordinary diesel locomotives simply cannot meet the demand for transport due to the high altitude and thin oxygen. Therefore, China considered the use of locomotives when the qinghai-tibet railway was still under construction. Since spherical lightning is prone to occur in summer in the qinghai-tibet plateau, it is not suitable for the construction of electrified railway. However, the ordinary diesel locomotive could not meet the demand. At this time, the domestic plateau diesel locomotive was still in the experimental stage, so China had to purchase 78 nj-2 plateau diesel locomotive from the American general electric company to ensure the smooth operation of qinghai-tibet railway.

The nj-2 plateau diesel locomotive is specially designed for the plateau region, with a power of up to 3000 kilowatts, even at an altitude of 5000 meters, it also has 2500 kilowatts. Trains on the qinghai-tibet plateau are typically in a reconnection mode, with the combination of two locomotives capable of moving the carriages smoothly, and a top speed of 120 kilometers per hour. Although there were some problems with the nj-2 diesel locomotive at the early stage of operation, there were no major problems after it was perfected in the later stage. It can be said that the smooth operation of the qinghai-tibet railway over the years nj-2 plateau diesel locomotive contributed.

So for so many years there is no corresponding diesel locomotive can be used in China? Why does the qinghai-tibet railway use locomotives imported from the United States? In fact, as mentioned above, when the qinghai-tibet railway was constructed, China's plateau diesel locomotive was developed on the basis of the dongfeng 8B diesel locomotive. The two prototype vehicles of the df-8b plateau locomotive, named "snow land shenzhou", were responsible for transporting materials needed for the construction of the qinghai-tibet railway since 2002, and all aspects of the assessment also met the design requirements.

However, the original ministry of railways decided in 2003 that China's railways should achieve "leapfrog development" instead of moving forward slowly on the original basis. China could introduce advanced locomotives or technologies from abroad in order to shorten the gap between China and developed countries in the shortest time and eventually catch up with them. Therefore, under this general trend, the domestic "snow land shenzhou" had no chance to get the order, which was finally given to the general electric company of the United States to make the nj-2 plateau diesel locomotive.

Although the emergence of nj-2 plateau diesel locomotive has solved the lack of reliable locomotives in qinghai-tibet railway in a timely manner, with the continuous improvement of qinghai-tibet railway's transport capacity, the gap of diesel locomotive gradually appears. If there is no domestic plateau locomotive, the qinghai-tibet railway is always at risk of being jammed by foreign countries, so in this case, the former CNR began to find ways to break through this bottleneck. After years of efforts, the hxn-3 plateau locomotive began to be tested on the qinghai-tibet railway in 2014. On June 10, 2018, the hxn-3 plateau diesel locomotive and the nj-2 plateau diesel locomotive executed the Z6801 golmud to Lhasa passenger train in the form of multiple connection and successfully reached the destination. This means that the domestic plateau diesel locomotive has been able to meet the needs of the qinghai-tibet plateau, China will no longer have to rely on American locomotives.

Although the nj-2 plateau diesel locomotive is still the main locomotive of qinghai-tibet railway, we believe that with the passage of time, American locomotives will all be phased out sooner or later, and China's domestic plateau diesel locomotive will become a beautiful scenery on qinghai-tibet railway.