Highland Railway - Jones locomotives
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The Highland Railway was a Scottish railway in which David Jones (1834- 1906) was its locomotive superintendent. He was credited with the design of the first British 4-6-0 that was strongly influenced by the Scottish locomotive design for Indian Railways. The 4-6-0 wheel arrangement that appeared in 1894, quickly became the most common locomotive for passenger and mixed traffic work in Britain.
Although Jones was a fervent disciple of Alexander Allan, Jones' new designs tended to break away from the Allan tradition, which had lasted so long in Scotland. One Allan feature that Jones did not perpetuate in his 4-6-0s was double framing around the outside cylinders. Allan's straight-link valve gear was, however, retained; this was basically similar to the corresponding Stephenson gear, but the link was easier and therefore cheaper to make and imparted a constant lead irrespective of cut-off. The "Drummond" Castle class was, mechanically, Jone’s personal design, although the Drummond stamp of chimney, cab and 'water-cart' bogie tender was unmistakable. A dubious asset, without which none of the younger Drummond's locomotives was complete, was the provision of steam reverse, a troublesome mechanism if it were not well maintained.
With the introduction of the 4-6-0, Highland Railway had thus obviated the 0-6-0 employed by practically every other British railway, except its most intense competitor, the Great North of Scotland Railway. A 0-6-0, however, would have meant a crank axle, and crank axles did not have a place in Jones' designs.
Jones’ other new designs also tended to break away from the Allan tradition, although he continued to use the Allan link valve gear:
- His Loch class 4-4-0 had a very high power/weight ratio and was among the several classes carrying his special louvered chimney. This invention involved the division of the chimney into a central exhaust tube and an outer concentric ring into which air was projected through the louvre slits down the front of the chimney casing. The increase in air resistance was induced by deflector plates. By this means, a draught was supplied when the engine was running with its steam cut off, as happened for long stretches on the hilly Highland line.
- There was one 0-4-4 tank, the only detail, now available, seems to be a photograph of the inaugural train of the Wick and Lybster Light Railway arriving at Lybster; a generally Stroudley-Jones appearance, with inside cylinders.
- There was one 0-4-2 tank about which, nothing is known.
- By 1892, there were also three 0-6-0 tanks. Whether one of these was the Stroudley rebuild of 1871 is not recorded.
In 1871, Lochgorm assembled a new 2-4-0. No details seem to be available, but three such with 6 feet 3 inches driving wheels are known to be available in 1892.
