JS Class 2-8-2s
The JS class 2-8-2 was a product of co-operation between China and the USSR in the 1950s. The rolling chassis of the successful JF class mikado was improved and paired with a new boiler based on Soviet practice to produce a capable mixed traffic locomotive. The new engines were intended for main line service and were equipped with mechanical stokers and feedwater heaters, resulting in a considerable increase in power over their predecessors.
The standard JS. Tonghua's JS 5031 had the full smoke deflectors carried by the majority of the class for most of their working lives.
From 1986, a modified design, the JS "B", was produced. This incorporated a number of modifications aimed at easing maintenance and making the locos more suitable for trip working and shunting service. The most visible change was the adoption of a single slide-bar arrangement, similar to that used on the QJ class 2-10-2s, to replace the double slide-bar design inherited from the JF.
The JS went into production at Dalian in 1957 and at Qishuyan, Datong and Beijing (Feb 7th) in later years. Between 1957 and 1965, 1135 locomotives were constructed. After a gap of 16 years, Datong started building JS again in 1981 and had constructed 358 more engines to the original design by the time the revised JS "B" specification was adopted in 1986. A total of 423 JS "B" were built before steam production finished at Datong in December 1988. The final batch of locos built were QJs but the vast majority of engines built in 1988 were JS Class.
Nancha's JS 5431 was fitted with high smoke deflectors and had no chimney cowling. The buffer beam and front steps had also been modified. The resulting engine looked very different to the standard locos. High deflectored JS were common in some areas and numbers were spread throughout the range. They were thought to be local customisations as details varied from loco to loco.
Compared to some of the major classes, JS numbering is reasonably straightforward. The original 1950s and 1960s built locos were numbered from JS 5001 to JS 6135. Starting at 5001 avoided overlapping the numbers of the various types of JF occupying the 1 - 4100 (approx) range. The locos constructed at Datong in the early 1980s were numbered from JS 6201 to JS 6558, while the final JS "B" locos carried numbers between JS 8001 and JS 8423. The last built was JS 8422 which emerged in December 1988. JS 8423 was an earlier JS "B" built by Datong for use as a works pilot and numbered JS 9999. When it became surplus to requirements, it was renumbered JS 8423 and sold to industry.
There are some non-standard and renumbered JS, but not many. JS 1001 at Pingzhuang is one of them but it isn't known if it was renumbered or built specially for industry and numbered in a separate series. There have been no other reports of locos with similar numbers. Wuhan steelworks renumbered JS 6256 - 6258 as JS 001 - 003. One of these engines, numbered JS 6257, was seen at Wuchangbei in 2000 indicating that the original numbers may have been restored. The most unusual numbers were carried by the four JS at Baotou steelworks. JS 58001 - 58004 were built in 1958 and may have carried these numbers from new. Some doubt has been expressed over the true identity of JS 5801 - 5809 and JS 6002 - 6004 at Anshan steelworks but there doesn't appear to be any hard evidence that these aren't their original numbers. Two of the locos, JS 5808 and 5809 were Shenyang Bureau engines, seen in the Jilin area in the 1980s so their appearance at Anshan in the 1990s would seem to be entirely plausible.
Most of the JS still in traffic are from the 1980s Datong batches and have no smoke deflectors. Pingdingshan's JS 8062 is a JS "B" and clearly shows the single slidebar arrangement fitted to 8000 series engines.
As would be expected with such a large class of modern engines, JS could be found all over the network until the very end of CNR steam. Many of the 1980s built engines went straight into industrial or local railway service while others were sold to industry when their CNR careers were over. A considerable number were still in service at the turn of the century and several dozen are still in use in 2012, particularly at the opencast coal mine at Sandoling in Xinjiang.